‘5'" THE EFFECT OF SOIL TREATMENT ON THE ACCUMULATION OF IONS BY SEVERAL CROPS by KENNETH McALPINE PRETTY AN ABSTRACT Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY 1958 Department of Soil Science Approved by (:F{.l__.CE>F1WéE7 .1 '11!” .i..(. {:1 dun. '*'mmwiwfiwWfifiW#mu’ . .- m ' . w ,u ‘rv .4 nil—fl“ ——-———.’.m‘,- _ .-.~ g f ABSTRACT lienneth McAlpine Pretty Field studies were conducted over a two-year period to determine the effect of unbalanced soil fertility conditions on the growth and chemical composition of several crops grown on an in- fertile Kalamazoo sandy loam soil. Calcitic and dolomitic lime. phosphorus and potassium were applied singly and in combination to give a total of twelve treatments. Yield data and chemical composition were determined for timothy and soybean hay, as well as the mature grain of millet, soybeans, corn and wheat. The content of the various nutrients in the soil following treatment was determined and related to the content of the same elements in the plant. In addition, the manganese, total nitrogen and crude ash content of the various crOps was determined. Phosphorus significantly increased the yields of soybean hay and millet in 1955, while potassium depressed the yield of soybean seed. In 1956 phosphorus applications increased the yield of winter wheat and potassium increased corn and millet yields. Both liming materials increased wheat yields in 1956, while only dolomitic lime increased the yield of corn. Calcitic lime in- creased timothy yields but dolomitic'lime had a depressing effect. In the majority of cases applying the various nutrients to the soil resulted in an increased content of that element in the plant. However, with the exception of phosphorus, the overall composition of seeds was not substantially changed. Timothy and soybean plants showed an appreciable increase in the content of calcium, magnesium and potassium when these elements were applied to the soil. The cation composition of soybean seed tended to remain more constant than any other crop studied. ——--_;.. -.—- Kenneth McAlpine Pretty 2 The sodium, nitrogen and crude ash contents of plants were not substantially or consistently altered by soil treatment. How- ever, there was a tendency for lime applications to increase the nitrogen content, and phosphorus and potassium fertilization to increase the crude ash. Calcitic and dolomitic lime reduced the manganese content of all crops. The potassium—magnesium interaction in plants was the most important relationship determining changes in cation content. Potassium applications usually depressed magnesium accumulation and vice versa. However, these changes did not occur in equivalent amounts. The total cation content was increased or decreased by magnesium and potassium fertilization, depending on the extent of the interaction and the relative quantities of the two ions in the plant tissue. Due to these interactions changes in cation ratios in the plants were not necessarily related to changes in the same ratios in the soil. Changes in the composition of various plant species as a result of soil treatment can be caused by a number of factors, including the relative activity of the ions on the soil colloid, the varying cation exchange capacities of roots, the presence of specialized absorption sites or ion-carrier mechanisms, and the effect of climate on the physiological processes of the plants. Seeds apparently possess specialized absorption mechanisms by which certain ions can be selectively excluded. The extent to which the recorded differences in crop composi- tion may be a true index of nutritive value has not been determined Kenneth McAlpine Pretty 3 and the possibility of significant changes in more important, undetermined constituents is recognized. THE EFFECT OF SOIL TREATMENT ON THE ACCUMULATION 0F IONS BY SEVERAL CROPS by KENNETH McALPINE PRETTY A THESIS Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY 1958 Department of Soil Science (5 208627 5/24/92. TO MY PARENTS whose unfailing interest and constant encouragement have been a great source of inspiration, these results are affectionately dedicated ACKNOWLEDGMENTS The author wishes to express his sincere appreciation to Drs. James Tyson and R. L. Cook for their valuable counsel and constant interest during the course of this investigation. Grateful thanks is extended Mr. William Fischer, Manager of the W. K. Kellogg Farm of Michigan State University, for his cooperation and assistance in conducting the field phases of this study. The writer also wishes to express his thanks to the Board of Directors of the Rackham Foundation for providing the necessary funds to conduct this research. VITA Kenneth McAlpine Pretty candidate for the degree of Doctor of Philosophy Final Examination, May 13, 1958, 1:30 P.M., Room 210, Agriculture Hall Dissertation: The Effect of Soil Treatment on the Accumulation of Ions by Several Crops Outline of Studies: Major Subject: Soil Science Minor Subjects: Chemistry, Plant Physiology Biographical Items: Born, June 19, 1929, Wilkesport, Ontario, Canada Undergraduate Studies, Ontario Agriculture College, Guelph, Ontario, 1947-1954 Graduate Studies, Michigan State University, East Lansing, 1954-1958, M. S. Degree, December, 1955 Experience: Extension Specialist, Soil-Crop Improvement Association, London, Ontario, 1951-1954 Special Graduate Research Assistant, Department of Soil Science, Michigan State University, 1954—1957 Instructor in Soil Science, Michigan State University, ~1957-1958 Member of American SOciety of Agronomy, Soil Science Society of America, International Society of Soil Science, Society of the Sigma Xi, and the Honor Society of Phi Kappa Phi TABLE II. III. IV. VI. VII. VIII. IX. XI. XII. XIII. XIV. LIST OF TABLES Some Physical and Chemical Characteristics of the Soil Studied . . . . . . . . . . . . . . . . . . . . . Varieties and Dates of Planting and Harvest of the Crops Studied . . . . . . . . . . . . . . . . . . . . The Average Effect of Lime and Fertilizer Treatments on the Soil Nutrient Levels in 1955 . . . . The Average Effect of Lime and Fertilizer Treatments On the Soil Nutrient Levels in 1956 . . . . . . . . . The Effect of Lime and Fertilizer Treatments on Various Cation Ratios in the Soil . . . . . . . . . . . . . The Effect of Soil Treatment on the Yield of Several Crops Grown in 1955 . . . . . . . . . . . . . Analysis of Variance of 1955 Crop Yields . . . . . . . The Effect of soil Treatment on the Yield of Several Crops Grown in 1956 . . . . . . . . . . . . Analysis of Variance of 1956 Crop Yields . . . . . . . Percent Change Result of Lime in the Composition of Timothy Hay as a and Fertilizer Applications . . . . . Percent Change Result of Lime in the Composition of Soybean Hay as a and Fertilizer Applications . . . . . Percent Change Result of Lime in the Composition of Millet Grain as a and Fertilizer Applications . . . . . in the Composition of Soybean Grain as a and Fertilizer Applications . . . . . Percent Change Result of Lime in the Composition of Corn Grain as a and Fertilizer Applications . . . . . Percent Change Result of Lime in the Composition of Wheat Grain as a and Fertilizer Applications . . . . Percent Change Result of Lime The Effect of Soil Treatment on Certain Cation Ratios in Crops Grown in 1955 . . . . . . . . . . . . . PAGE 19 22 27 28 30 32 33 36 37 42 5O 57 63 68 73 76 PAGE The Effect of Soil Treatment on Certain Cation Ratios in Crops Grown in 1956.. . . . . . . . . . . 77 A Comparison of the Effect of Soil Treatment on the Composition and Yield of Crops . . . . . . . . 83 The Effect of Lime and Fertilizer Applications and 111 Crop Grown on the Nutrient Status of the Soil . . The Effect of Lime and Fertilizer Applications on the Chemical Composition of Crops Grown . . . . . . . 117 LIST OF FIGURES FIGURE PAGE 1. The effect of soil treatment on the composition of timothy hay grown in 1955 . . . . . . . . . . . . 39 2. The effect of soil treatment on the composition of timothy hay grown in 1956 . . . . . . . . . . . . 4O 3. The effect of soil treatment on the nitrogen and crude ash content of timothy hay grown in 1955 and 1956 . . . 41 4. The effect of soil treatment on the composition of soybean hay grown in 1955 . . . . . . . . . . . . . . . . 47 5. The effect of soil treatment on the composition of soybean hay grown in 1956 . . . . . . . . . . . . . . . . 48 6. The effect of soil treatment on the nitrogen and crude ash content of soybean hay grown in 1955 and 1956 . . . 49 7. The effect of soil treatment on the composition of millet grain grown in 1955 . . . . . . . . . . . . . . . 54 8. The effect of soil treatment on the composition of millet grain grown in 1956 . . . . . . . . . . . . . . . 55 9. The effect of soil treatment on the nitrogen and crude ash . content of millet grown in 1955 and 1956 . . . . . . 56 10. The effect of soil treatment on the composition of soybean grain grown in 1955 . . . . . . . . . . . . . . . 6O 11. The effect of soil treatment on the composition of soybean grain grown in 1956 . . . . . . . . . . . . . . . 61 12. The effect of soil treatment on the nitrogen and crude ash content of soybean grain grown in 1955 and 1956 . . 62 13. The effect of soil treatment on the composition of corn grain grown in 1955 . . . . . . . . . . . . . . . . 65 14. The effect of soil treatment on the composition of corn grain grown in 1956 . . . . . . . . . . . . . . . . 66 15. The effect of soil treatment on the nitrogen and crude ash content of corn grain grown in 1955 and 1956 . . . . 67 FIGURE 16. The effect of soil treatment on the composition of wheat grain grown in 1956 . . . . . . . . . . . . . . . . 71 17. The effect of soil treatment on the nitrogen and crude ash content of wheat grown in 1956 . . . . . . . . . . . . 72 TABLE INTRODUCTION . . . . . . . LITERATURE REVIEW . . . . . . EXPERIMENTAL METHODS . . . . Field Studies . . . Laboratory Studies . . . Soil Analysis . . . Plant Analysis . . . Interpretation of Results RESULTS . . . . . . . . . Soil Nutrient Content Crop Yields . . . . . . OF CONTENTS Chemical Composition of Crops Studied Timothy Hay . . . . . Soybean Hay . . . . . Millet Grain . . . . . Soybean Grain . . . . Corn Grain . . . . . Wheat Grain . . . . . Cation Ratios in Plants DISCUSSION . . . . . . . . SUMMARY AND CONCLUSIONS . . . LITERATURE CITED . . . . . . APPENDIX . . . . . . . . . . PAGE . 18 . 21 . 23 . 26 100 110 INTRODUCTION The existence of all life, plant. animal or human, is dependent, directly or indirectly, upon the soil. Plants rely on the soil for the nutrients, moisture, aeration and support necessary for them to grow and reproduce. Animals and man utilize these plants for food, and hence are dependent on the soil to supply their sustenance in sufficient quantity and quality to support normal growth and development. The importance of determining the extent to which the chemical composition or nutritive value of a plant can be changed by manipulation within the environment is evident. Although the magnitude of such changes is important from a nutritional stand— point, the factors governing these variations are of even greater significance. If it can be ascertained that plant composition can be substantially and consistently altered, and if the condi- tions responsible for such changes can be properly evaluated, then certain cause and effect relationships can be established which are applicable to a given environmental complex. Under normal conditions nutritional diseases caused by deficient or toxic levels of mineral elements in the diet do not occur. This is particularly true in human nutrition where the food consumed represents plant material grown in widely separated areas of the country or the world, and hence under ‘very diverse soil and climatic conditions. Nutritional disorders of animals are perhaps more commonplace due to the restricted area from which they derive the majority of their feed. Certain locations are known to be deficient in one or more essential nutrients, thus causing a characteristic upset in normal metabolic and physiological processes. The incidence of goiter in the Mid— west as a result of low iodine levels in soils and plants is an example of such a mineral deficiency induced disorder. Cobalt, calcium and phosphorus deficiencies of animals in the United States, as well as selinium toxicity, have been related to the available levels of these elements in the soil. Consequently, any funda- mental studies on dietary deficiencies must begin with plants and the soil upon which they were grown. “ The chemical composition of a plant is a reflection of the environment in which it is grown, together with limitations im- posed by the genetic constitution and uniformity of protoplasmic composition of species or varieties. The external environment of the plant is influenced by such factors as climate, plant compe- tition, stage of maturity, soil type and level of available nutri- ents, as well as many other complex physical, chemical and bio- logical relationships. This study was undertaken to further examine the effect of unbalanced fertility levels in the soil on the growth of agriculturally important plant species, and more particularly, on the accumulation of mineral elements by these crops. An extensive study, recently concluded, indicated that the change in chemical composition of plants grown under field conditions as a result of fertilizer application was not great (Duncan, 1955a). However, this experiment was conducted under conditions of balanced high and low soil nutrient levels as indicated by soil tests. Other research work showed that plant composition could be changed by unbalanced soil fertility under conditions of controlled green- house environment (Power gt 21, 1955). 1 The above studies failed to show the effects of wide vari- ation in soil nutrient content upon the chemical composition of plants grown under the complex, variable environment of field conditions. Consequently, this was the primary objective of the present investigation. More specifically, it was designed to determine the influence of calcium, magnesium, phosphorus and potassium fertilization, singly and in combination, on the nutri— tive value of several crop species, insofar as this value can be assayed by chemical composition of the plant. A further, and more fundamental objective, was to determine certain basic rela- tionships which are operative in establishing variations in plant composition so that these results might be of value in inter- preting data from similar studies in the future. l4. —-——ry LITERATURE REVIEW The literature dealing with the effect of various chemical. physical and biological relationships on the accumulation of mineral elements by economic plants is voluminous. A complete discussion of all of the factors influencing the nutrient content of such plants is outside of the scope of this manuscript. Compre— hensive reviews of previous work relating plant growth and compo- sition to environment have been presented by Gauch (1957), Shaw (1952), Truog (1951) and Stout and Overstreet (1950). Many factors contribute to the final yield and composition of a plant. Each factor, acting individually, may have an almost insignificant effect. However, the sum total of all components, and particularly the combinations of these factors, will result in a plant which is the product of its environment. Among the factors known to have a profound influence on the growth, development, and composition of plants are (a) the soil, its chemical, physical and biological characteristics, both in its natural state and as altered by management, (b) the plant, its genetic and physico-chemical constitution, its stage of matur- ity, and its manipulation within the environment, and (c) the climate, that is, temperature and rainfall as it affects the soil substrate and the plant itself. Truog (1951) aptly commented "The soil is, indeed, an intricate dynamic system, and to under- stand how a fertile soil may function as a well nigh perfect medium for plant growth requires much study and considerable imagination." Beeson (1947) stated, "When one considers the complexity of the biological system under which we produce our food crops, one will recognize as natural the variable results obtained by the superimposition of a fertilizer on a set of soil conditions." Similar statements could be made concerning the complexity of the plant factor. That soils do differ widely in their ability to supply nutrients, and hence to support optimal plant growth, is an universally accepted fact. Recently, considerable effort has been devoted to studying fundamental differences between soils as they affect the nutrient supplying power of the soil. Studies by Chu and Turk (1949), Mehlich and Colwell (1943), and by Marshall and his associates (1950, 1951), indicate that the clay fraction is most important in determining the availability of ions. Attention has been given to the interaction of different soil colloids with such other properties as base saturation and exchange capacity. Emphasis has also been placed on the relative bonding energies of the various ions. Mattson (1948) has stated the relationship between avail— ability of ions and clay mineral type as follows, "If two soils having different cation exchange capacities (due to different acidoid content or strength) contain the same proportion of a monovalent and divalent ion, the soil with the higher exchange capacity should yield its monovalent ions more readily and its divalent ions less readily." An example of this relationship is the often observed fact that potassium is absorbed more readily by plants from the 2:1 mineral colloids than from the 1:1 clays (Mehlich and Reed, 1948). The ionic associations on the exchange complex have an important bearing on nutrient availability to plants. Marshall and his associates (1950, 1951) have demonstrated that the re- placement of H+ ions on a soil colloid by calcium or magnesium increases the activity of a given amount of exchangeable potassium. The selection of ions by plants is more closely related to the active portions in the soil than to the total exchangeable amounts. Hence changing the ionic atmosphere by the application of nutrients in the form of fertilizers or other soil amendments could be expected to exert a considerable influence on ion avail- ability to plants. The concept of a static soil solution serving as the sole source of nutrients has been discarded by most soil scientists. Marshall (1951) has pointed out some of the shortcomings of this belief. Since that time other workers have contributed to the idea that the exchangeable ions must be looked upon as being the immediate source of cationic plant nutrients in most soils (Mehlich and Coleman, 1952). It must be realized, however, that the ions in solution, or those retained on the clay and organic matter complexes by exchange mechanisms, are by no means the only source of nutrients. If this were so, soils would rapidly become depleted of nutrient reserves so that ion accumulaticn and growth by plants would cease. Graham and Albrecht (1952) and Steward and Volk (1946) have reported studies on the release and subsequent uptake of potassium from nonexchangeable sources. Lawton and co—workers (1956 and 1958) have reported the uptake of phosphate from in- soluble or weakly soluble sources applied to soils. Certain physical relationships in soils can affect the absorption of nutrients, although the extent of this effect may vary with the plant and ions under study. Withrow (1951). in a review of the effect of light on the mineral nutrition of plants, has stated, "Light is not known to play any direct role indispens— able for the absorption, movement, or metabolism of the mineral nutrients. Although light rarely strikes the absorbing surface of plants, that is, the roots, there may be an indirect effect resulting from the temperature rise concomitant with the absorption of light and from the basic photochemical reactions occurring in plants, such as photosynthesis, chlorophyll synthesis, photo- morphogenesis, and photoperiodism." Apart from a favorable soil reaction and an adequate supply of essential nutrients, the soil factors associated with an ade— quate supply of all essential nutrients are (a) a favorable supply of water, (b) adequate oxygen, (0) favorable temperature, and (e) friability or looseness of the soil so that roots are not restricted in their free growth and development (Page and Badman, 1951). Although these factors may be most noticeable in terms of crop yields, differences in ion accumulation have been noted. Cartter and Hopper (1942) reported results of a regional study with soybeans in which high temperature increased the cal- cium content of the seed produced by a given variety. Hoagland and Broyer (1936) and Broyer and Overstreet (1940) conducted experiments with excised barley roots in which they were able to show that potassium accumulation increased with increasing temperature. up to a maximum. However, in all of these studies, particularly those conducted in a soil medium with intact plants, any effects which temperature may have had on the solubilization of nutrients in the soil, on the ion absorption mechanism of the root interface, and on the translocation and utilization of the nutrients within the plant, cannot be readily separated. Soil moisture is one of the variables in plant growth in the field which affects the absolute activities of cations and probably their ratios to one another (Peterson and Krackenberg, 1954). Richards and Wadleigh (1952) suggested that under condi— tions of adequate nutrient supply, plants that are limited in growth by a relatively low level of soil moisture will have a higher content of mineral nutrients than plants under comparable fertility but not limited in growth by moisture supply. Daniel and Harper (1934) noted that the calcium content of grasses and alfalfa grown under different fertilizer conditions in Oklahoma decreased and the phosphorus content increased during periods of high rainfall. When effective rainfall was low the reverse was true. Freeland (1936, 1937) indicated that soil moisture, through its effects on transpiration rates, affected the rate of potassium uptake by corn, beans and sunflowers. The influence of soil aeration on plant growth and nutrient absorption has been reviewed by Russell (1952). Lawton (1945) noted that the order of reduction in nutrient absorption by corn from Clyde silt loam soil because of restricted aeration was K>Ca >Mg>N>P . Cline (1957) studied oxygen diffusion rate as an important factor in soil aeration and nutrient absorption by peas. Stubblefield and DeTurk (1940), in reporting results of their studies on the effect of seasonal conditions on the composi— tion of corn, oats, and wheat, have stated "Weather conditions exert a pronounced effect, with the result that crops grown on the same plot in succeeding years may vary as much in chemical composition as crops grown on different plots." Plants differ in their abilities to absorb nutrients from a given medium. Much of this difference in plant species has been attributed to variations in cation exchange capacity of the plant roof surfaces (Mehlich and Drake, 1955; Elgabaly and Wiklander, 1949). Drake, Vengris and Colby (1951) have listed the exchange capacities of the roots of many mono— and dicotolydenous plants showing a range from 30.4 to 10.5 m.e./100 grams oven-dry tissue for the former and from 94.0 to 25.0 for the latter. McLean and Baker (1953) made activity measurements of Na, K and Ca- saturated roots of several plant species, and from this calculated the mean free bonding energy of the cations. Plant roots with _ A;- Tim .. L‘s; relatively high cation exchange capacities had bonding energies for calcium which were more than double the bonding energies for potassium. Using roots of low cation exchange the bonding energy of calcium was about 50 percent of the value with higher cation exchange roots, whereas potassium was held with about 80 percent of the energy of the higher exchange roots. The significance of these studies on the ability of plants to absorb or exclude ions has been the subject of extensive re- search and speculation. Epstein and Hagen (1952) postulated the presence of ion—binding compounds generated by metabolic processes, these compounds being specific for certain ions. Mattson (1948) has used the Donnan principle to help ex- plain the differences in monovalent and divalent cation absorption by colloids of high and low cation exchange capacity. According to his theory, the higher the cation exchange capacity of roots, the greater is the relative absorption of divalent over monovalent ions, since the activity of the divalent cation is inserted as the square root in the Donnan distribution. Elgabaly and Wiklander (1949) pointed out that the root and soil colloids compete for cations, so that the cation uptake by the plant depends upon the relative exchange capacities of the root and soil. However, as Mattson has stated, it is only when nearly all of the cations exist in an exchangeable state and the plant root colloids must compete with soil colloids for these cations by exchange that the Donnan distribution will be reflected in the composition of plants. By an increase of free electrolytes, the inequalities of the Donnan distribution of ions will be evened out. Although the prediction of cation content in plants ap— pears promising under conditions of limited root extensions, substantial failures may be encountered with field-grown plants where the proportions and concentrations of cations vary widely in different zones of root penetration (Mehlich and Drake, 1955). Other factors, intimately associated with physiological differences between plant species, may be operative in deter- mining the rate and extent of ion accumulation. Newton (1923) suggested that the observed species differences in cation ratios aretafunction of the capacities of their root systems to produce carbon dioxide. Calcium accumulation was especially favored by release of carbon dioxide. Broyer (1951) has pointed out various hereditary limitations to ion accumulation by plant species. Collander (1941) also conducted numerous experiments to illustrate that the extent of physicochemical processes may be predetermined by ancestral characteristics. The age of the plant, stage of maturation and associated rate of metabolic activity, and translocation of absorbed ions are all of importance in determining ion accumulation (Broyer, 1951). Tyson (1930), working with sugar beets, found that the percentage of minerals in the plant was usually highest in the spring when the young plants were making most rapid growth, and lowest during the summer. Beeson (1941) also indicated that the nutritive elements generally attain maximum concentrations 12 during the early part of the life of the plant. Ulrich (1946) and Sayre (1948) noted a decreased potassium content of plant tissue as the growing season progressed. Various authors have noted that certain plant parts have the ability to selectively exclude certain ions while accumulating relatively large amounts of the others. However, the specific mechanism for such selectivity remains to be elucidated. Loehwing (1951) indicated that in many annuals a large part of the mineral - nutrients are absorbed early in the life of the plant. As the plant passes from the initial anabolic stage to the catabolic stage just preceding flowering, important changes may occur in the mineral nutrient levels. Along with the redistribution of ions there is commonly a low level of root carbohydrate supply associated with a low absorption activity at this stage of growth. McMurtrey (1947) observed that the magnesium and phosphorus content of the reproductive organs of plants increased during ripening. Cooper, Paden and German (1947) commented on the relatively small amount of calcium in the carbonaceous parts of plants such as seeds, roots and tubers. and noted that the amount of magnesium in these parts is nearly always greater than the amount of calcium. Wallace, Toth and Bear (1948) studied the location of sodium in various plants and found a tendency for it to be concentrated in conductive tissues. Beeson (1947), in his classic study on plant composition, has noted the variable elemental content of plant parts. 13 Depending on the intensity and the combination of various soil and plant factors already discussed, the application of one or more nutrient elements may have a variable effect on the chemical composition of plants grown. Naftel (1937), Bender and Eisenmenger (1941), Vlamis (1949) and MacLean (1956) all reported an increased content of calcium in a range of crop plants as a result of lime applications. 0n the other hand, Chambers and Gardner (1951) found that the content of calcium in wheat was A almost unaffected by liming, although the total uptake of calcium was increased due, primarily, to increased plant size. Beaumont and Snell (1935) obtained an increased content of magnesium in corn stover, oats (grain and straw), barley (grain and straw), millet and buckwheat as a result of magnesium application. No change was observed in rutabagas or Sudan grass. Taylor (1954) and Carolus (1935) also noted an increased magnesium content of plant tissue with increasing available supplies in the soil. Lawton and Cook (1954), in a comprehensive review of the literature, have pointed out that the potassium content of crops is generally increased as the level of exchangeable potassium in the soil is increased by the use of fertilizer, provided the level of soil potassium initially present is not extremely high. Bear and Prince (1945) have reported luxury consumption of potas— sium by alfalfa, while Windham (1953) found that the potassium content of 19 vegetable crops was usually increased by generous 14 applications of potassium fertilizers. the extent of this increase being dependentcniplant species. There is ample evidence in the literature that the accumula— tion of many micro-nutrients by plants is closely related to available supplies in the soil. Epstein and Stout (1951) and Lyon and Beeson (1948) made their observations with manganese. Steckel gt 2; (1949) observed that the manganese concentration in oat and soybean plants was increased by soil applications of manganese sulfate. Fujimoto and Sherman (1948) noted that plant absorption of manganese was decreased by the addition of lime to the soil, thereby depressing the level of available manganese. Variations in the phosphorus content of plants due to phos- phate applications have been less marked. Blair and Prince (1939) found only a slight increase in the total percent phosphorus in alfalfa with increasing phosphorus applications to the soil. Studies in Michigan by Williams (1955) showed that increasing rates of application of superphosphate tended to increase the total phos— phorus content of sugar beets, field beans and wheat. Wedin st 21 (1956) found that phosphorus applications also increased the level of phosphorus in the plant. of perhaps even greater significance in plant composition is the effect which the soil application of one ion exerts on the availability and/or accumulation of another. Practically all possible relationships between ions have been reported at some time in the literature. However, only those interactions which are most widely accepted will be reported here. x, ' . t: -. sii‘ I‘ll” f Peterson and Knackenberger (1954), in summarizing the inter- relations of bases in calcium absorption, stated that an increase in the supply of absorbable calcium or magnesium tends to decrease the absorption of potassium from a low potassium medium, although this effect is likely to be less marked than the reverse. Carolus (1938) noted that nitrogen-phosphorus-potassium fertilization re— duced calcium and magnesium absorption. Adequate absorption of calcium, magnesium and potassium could only be obtained by calcium- magnesium-potassium fertilization. McCalla and woodford (1935) also found that low potassium supplies markedly increased the cal- cium and magnesium content of wheat. Prince and co-workers (1947), in studying the release of magnesium from New Jersey soils, con- cluded that the most important single factor influencing the mag- nesium uptake by plants was the quantity of available potassium. . As the potassium supply decreased the magnesium content of the plant increased, even when the plants were growing on a soil quite deficient in magnesium. Contrasting results on the influence of calcium levels on the uptake of magnesium have been presented by Carolus (1933) and Naftel (1937). Increased phosphorus uptake as a consequence of magnesium applications to soils have been reported by several workers (Truog st 21, 1947; Beeson, Lyon, and Barrontine, 1944). The presence of a positive correlation between the phosphorus and magnesium contents of plants, or between the efficiency of phos- phate fertilizers and the supply of available magnesium, has been reviewed by Beeson (1941, 1946). 16 Among the basic cations absorbed. potassium, calcium, mag— nesium and sodium, it is often noted that a decreased absorption of one ion is approximately balanced by an increased absorption of another, so that the total equivalents of cations in plant tissue will remain essentially constant (Lucas and Scarseth, 1947; Shear gt 2;, 1946; McCalla and Woodford, 1938; and van Itallie, 1938). However, these workers have admitted that there are certain exceptions to this rule. There is also a tendency to maintain a cation:anion balance in plants (Bear, 1950; McCalla and Woodford, 1938). Apparently an excess absorption of either cations or anions by the plant is balanced by the changing content of organic acids within the plant so that the reaction of the plant sap remains essentially unchanged (Hoagland and Broyer, 1940). This metabolic change within the root during the absorption process occurs primarily in the concen- tration of the malic acid fraction (Jacobson and Ordin, 1954). The effects of chemical composition and quality of crops on the health, growth and reproduction of animals or humans util- izing these crops has been extensively studied. Research conducted over a ten-year period by workers at the Michigan Agricultural Station failed to show any differences in the rate of growth, vigor, milk production or reproductive ability of matched herds of dairy cows fed on fertilized and unfertilized crops (Dexter gt El, 1950; Duncan gt 2;, 1952; Duncan, 1955b; ward st 21, 1955). Similarly. no differences were obtained in the growth of rats fed on the cow's milk (Cederquist and Ohlson, 1955). Analyses of the feedstuffs used in these studies indicated that the composition of timothy hay was favorably influenced by fertilization, while the relatively small differences that occurred in the composition of soybeans, corn, wheat, oats and brome hay in any one year could not be attributed to fertilization (Duncan, 1955a). According to the concept of plant nutrition proposed by Shear, Crane and Myers (1946) these results may have occurred because lime and fertilizer applications only increased the intensity of nutrient supply, but had no effect upon the balance of nutrients in the soil. Subse- quent studies on this same soil did show that unbalanced nutrient levels could cause changes in plant composition (Power, Swenson and Cook, 1955). Although nutritional disorders can be induced by restricting the kinds of feed or the content of any particular element in the feed, deficiencies in the diets of man or domestic animals have not been of general consequence because of the relatively small requirements for many elements and the varied selection of food- stuffs generally available. Nevertheless, deficiencies or toxicities of one or more elements can occur in localized areas, particularly where domestic animals are confined to feed produced in those areas. The many nutritional disorders of animals as a result of nutrient deficiencies in the feed have been reviewed by Underwood (1956) and Morrison (1947). EXPERIMENTAL METHODS Field Studies Field experiments were initiated on an extremely infertile Kalamazoo sandy loam soil in May of 1955 to determine the effect of unbalanced applications of calcium, magnesium, potassium, and phosphorus on the chemical composition and quality of several feed crops, namely, timothy hay, soybean hay, millet, wheat, corn and soybeans. With the possible exception of millet, these crops are commonly grown in Michigan and are widely used for livestock feed. In addition, corn, soybeans and wheat, or portions thereof, are of considerable importance in human nutrition. The results of other experiments conducted on this same soil have already been cited (Dexter, 1950; Duncan, 1955; Power, 33 31, 1955). These experiments indicated that no extreme nutrient unbalance existed in the untreated soil but rather the nutrients were properly balanced at a very low level of fertility. Records shcwed that the experimental field had received very little fer- tilizer or lime for a pericd of at least twenty years. Some of the characteristics of the experimental soil are given in Table I. A total of twelve treatments were used, each replicated three times. Each plot measured one rod by five rods. The twelve treatments were randomized across the width of the experimental area, while the six crops were randomized across the length of each block. TABLE I SOME PHYSICAL AND CHEMICAL CHARACTERISTICS OF SOIL STUDIED Available Phosphorus (lb/acre) ......................... 24 Percent Potassium Saturation ......................... 1.5 Percent Calcium Saturation ......................... 24.1 Percent Magnesium Saturation ......................... 3.8 Percent Sodium Saturation ......................... 1.8 Exchangeable Manganese (ppm) ................... ...... 94 Cation Exchange Capacity (m.e./100 grams) ............. 5.75 Soil pH ........................................... 5.2 Soil Series ..................................... Kalamazoo Texture of Surface Soil ................... sandy loam Type of Clay (predominant) ..... .......... .... Illiteb a aValues represent average of 20 samples from experimental area. b Stolzy, L. 1954. Unpublished Ph. D. thesis, Michigan State College Calcitic and dolomitic limestones, phosphorus and potassium were applied in all possible combinations. Four treatments re- ceived no lime. 0n the plots receiving lime, meal grade calcitic limestone, with a neutralizing value of 87 was applied in amounts equivalent to four tons per acre of pure calcium carbonate. Dolo- mitic limestone meal, with a neutralizing value of 106 was applied in equivalent amodnts to a second series. The limestones contained 9 and 45 percent magnesium carbonate, respectively. Treble superphosphate (45 percent P205) was applied at the rate of 1250 pounds per acre, while muriate of potash,(60 percent K20) was applied at the rate of 500 pounds per acre on those plots designated to receive these nutrients. With the exception of the timothy plots, one-half of the fertilizer and lime was applied before plowing, while the other half was applied after plowing and worked into the top three or four inches of the soil. In addition, all plots received a uniform application of 40 pounds per acre of nitrogen in the form of urea prior to plowing. As the original sod was timothy, one series of plots in. each replicate was left unplowed to serve as the hay crop. The complete applicaticn of lime, phosphorus and potassium was made as a topdressing on these plots. All fertilizer and lime applications were made during the period May 20 to 30. In 1956, considerably smaller quantities of lime and ferti- lizer were applied. Hydrated calcitic and dolomitic lime was ap— lalied to the appropriate plots in amounts equivalent to 1,000 21 pounds per acre. Treble superphosphate (45% P205) and muriate of potash (60%IK20) were applied at the rate of 200 and 100 pounds per acre, respectively, to plots receiving these elements. All applications, with the exception of those on timothy plots, were made following plowing. Table II includes a summary of the crop varieties or strains used in the experiments, together with the dates of planting and harvest. Soil samples were taken from each plot in 1955 and 1956 at the time of crop harvest, or shortly thereafter. Each sample represented fifteen to twenty cores to a depth of six inches. Laboratory Studies Soil Analysis The soil samples obtained from each plot were air-dried and screened through a 2-mm sieve. One hundred gram samples of soil from each of the three replications of each treatment were thoroughly mixed together and saved for composite soil analysis. A mechanical analysis was made on the soil using the hydrometer method of Boyoucous (1936). Soil pH measurements were made on noncomposited samples, using a 1:1 soil-water ratio'and a Beckman model 8-2 glass electrode, line-Operated pH meter. Available phosphorus was estimated by the method of Bray (1945). The extracting solution consisted of 0.03 N ammonium fluoride in 0.025 N hydrochloric acid. A soil-extracting solution ratio of 1:50 was employed. 4—4 TABLE II DATES OF PLANTING AND HARVEST OF EXPERIMENTAL CROPS IN 1955 AND 1956 Crop Variety Date of Planting Date of Harvest 1955 1956 1955 1956 Timothy haya Unknown —--- ---- June 28 July 2 Millet Proso June 16 June 21 Sept. 27 Oct. 6 Soybean hay Blackhawk June 4 June 2 Sept. 2 Aug. 29 Soybeans Blackhawk June 4 June 2 Nov. 5 Oct. 9 Corn Michigan 351 June 4 June 2 Nov. 5 Oct. 20 Wheatb Gennessee Sept. 24 ---- —-—- July 19 aEstablished sod bWinter wheat planted in 1955 and harvested in 1956. Exchangeable cations were removed from the soil by leaching with neutral, normal ammonium acetate. The method used was simi- lar to that suggested by Peech (1948). Potassium, sodium, and calcium concentrations in the ammonium acetate extract were deter- mined by using a Beckman model 0.0. flame photometer. Magnesium was determined by a modification of the thiazole yellow technique outlined by Drosdoff and Nearpass (1948). Values for exchangeable manganese were obtained by the periodate procedure of Willard and Greathouse (1917). Plant Analysis The plant samples were oven dried at 60° C. and ground in a Wiley mill. Twenty-five gram samples of plant material from each replicate were composited and saved for subsequent analysis. Crude ash determinations were made by the A.0.A.C. procedure (1945). Values for total nitrogen were also obtained by the A.0.A.C. Kjeldahl distillation method. Two gram plant samples were wet digested with nitric and perchloric acid, diluted to a volume of 50 milliliters and saved for element analysis. Calcium, magnesium, potassium and sodium concentrations were determined using a Beckman model D. U. flame photometer. Phosphorus and manganese analyses were performed with the ammonium .molybdate and periodate colorimetric proce- dures, respectively. m Interpretation of Results Due to the scope of this investigation, and the number of analyses involved, it was deemed necessary to composite the soil and plant samples from the three replications. Such action pre- cluded the possibility of statistical analysis of the data, with the exception of crop yields, for which results were available for each replicate. An attempt was made to calculate correlation coefficients between soil levels of any one nutrient and the content of any or all constituents in the plant. Such a procedure was discarded, however, as being conducive to erroneous interpretation and con- clusions. Changes in the nutrient level of the soil were relatively large compared to changes in plant composition. Hence, highly significant correlations were obtained in certain instances when even a cursory examination of the plant analysis data indicated that the magnitude of the changes in plant composition could not conceivably be statistically significant under conditions of normal biological variability. .Therefore, for the purposes of the present discussion, it is assumed that a variation in composition of approximately ten percent is of sufficient magnitude to warrant drawing conclusions regarding its causes and effects. Although such an assumption may be subject to criticism, it is considered to be supported by sufficient evidence in the field of soil fertility research so as to serve as a basis for interpreting the present data in terms of qualitative and quantitative factors influencing the accumulation of ions by plants. 26 RESULTS Soil Nutrient Content The effect of soil treatment on the level of available nutrients in 1955 and 1956 is presented in Tables III and IV, respectively. These data represent an average of all six crop areas in 1955, and all except the wheat plots in 1956. These latter plots were omitted from the 1956 averages due to the fact that they had not received the final additions of lime and ferti- lizer. Four tens of calcitic lime almost doubled the exchangeable calcium in the soil in 1955, while dolomitic lime gave less than a twenty percent increase. This is a reflection of not only the lower calcium content of the dolomitic lime, but also the lower solubility and subsequent slower dissolution of this material. This latter effect is even more evident when the exchangeable mag- nesium levels are compared. In spite of the fact that calcite contained only one-fifth as much magnesium as dolomite, it was equally effective in increasing the magnesium content of the soil. Both materials resulted in a threefold increase in exchangeable magnesium. Potassium fertilization increased the exchangeable potassium in the Soil by over 200 percent. Based on the rate of application, exchangeable potassium levels in the soil should have been increased THE AVERAGE TABLE III 27 EFFECT OF LIME AND FERTILIZER TREATMENTS ON THE SOIL NUTRIENT LEVEL IN 1955 Treatment Ca Mg K .Na ‘Pounds P.P.M. pH (percent saturation) P/acre Exch. Mn None 27.4a 3.7 2.0 1.1 26 63 5.2 P 29.5 3.4 2.0 1.3 144 64 5.1 x 24.0 3.1 4.4 1.4 31 75 5.2 PK 27.6 3.3 4.4 1.1 162 73 5.2 L1b 42.4 11.5 1.8 1.2 28 47 5.7 LIP 49.8 12.0 1.9 1.4 156 45 5.7 le 42.5 11.2 4.2 1.3 26 46 5.8 LIPK 47.0 11.7 4.1 1.4 155 48 5.8 L2° 34.5 12.3 1.9 1.3 28 47 5.5 L2? 35.2 10.7 1.8 1.3 152 50 5.5 L2K 27.5 10.8 3.9 1.3 28 46 5.6 L2PK 31.4 10.0 3.9 1.2 145 49 5.6 aAverage of all crop areas bCalcitic lime cDolomitic lime THE AVERAGE EFFECT OF LIME AND ON THE SOIL NUTRIENT TABLE IV 28 FERTILIZER TREATMENTS LEVELS IN 1956 4...“... f:.....i“.....§....’§“ 53:23.: 4.3.5:"... pH None 31.38 5.2 1.8 0.7 32 27 5.1 p 33.6 4.9 1.8 0.8 144 27 5.0 x 25.5 4.5 4.6 0.8 43 35 5.0 PK 29.7 4.5 4.9 0.9 176 36 5.1 le 77.1 12.3 1.7 0.9 35 11 6.3 Llp 74.6 11.8 1.8 1.0 156 12 6.4 11K 73.3 12.4 4.3 0.9 32 12 6.5 LIPK 80.0 12.2 4.7 1.0 159 13 6.6 L2° 51.4 40.3 1.8 0.9 30 9 6.5 L2? 55.2 36.9 1.7 0.9 189 10 6.4 sz 47.5 37.6 4.0 1.0 32 11 6.3 L29: 51.0 39.6 4.1 0.8 158 11 6.3 a . Average of all crop areas bCalcitic lime cDolomitic lime except wheat by about 400 percent. However, the difference between observed and expected values can be explained partly on the basis of plant removal and leaching, but more particularly by fixation of potas- sium in nonexchangeable forms. Phosphorus applications resulted in a five to sixfold in— crease in the level of available phosphorus. Here again, fixation would account for difference between observed and expected values. Exchangeable manganese levels in the soil were substantially decreased by lime applications. However, there was no difference between liming materials with respect to their influence on avail— able manganese. Phosphorus and potassium had no effect on man- ganese availability. Also. the soil treatments had no influence on exchangeable sodium levels of the soil. In 1956 exchangeable calcium values were 250 percent greater where calcitic lime had been used, and 75 percent higher where dolomitic lime was applied, as compared to unlimed plots. The use of dolomite resulted in a ninefold increase in exchangeable mag- nesium, while the values where calcite was applied were almost the same as the previous year. This large increase in calcium and magnesium levels in 1956 is primarily due to the use of hydrated lime which is more readily soluble than the coarser carbonates. Phosphorus and potassium fertilizers were applied in 1956 in amounts calculated to maintain the previously established levels. Within the limits of plot variation, this aim was accom- plished. TABLE V THE EFFECT OF LIME AND FERTILIZER ON VARIOUS CATION RATIOS IN THE SOIL 3O Ratio Lime Treatment Fertilizer Treatment -Ca-Mg +Ca-Mg +Ca+Mg -K 4K 1255 Ca/Mg 8.02 3.92 2.94 4.08 3.94 Ca/K 8.48 15.17 11.12 19.19 8.02 Mg/K 1.06 3.87 3.79 4.71 2.04 1256 Ca/Mg 6.33 6.30 1.33 2.90 2.77 Ca/K 9.21 24.36 17.67 30.42 11.52 Mg/K 1.45 3.87 13.30 10.49 4.16 Values for exchangeable manganese were ccnsistently lower on all plots in 1956. This is probably due to changing oxidation- reduction conditions in the soil as influenced by tillage, crop- ping and climate. Due to this variability, it has been shown that the exchangeable manganese content of a soil is not neces- sarily a good index of the manganese nutrition of plants (Hoff and Mederski, 1958). However, liming the soil reduced the ex- changeable manganese to one—third the original level. Table V lists some of the cation ratios in the soil in 1955 and 1956. It is evident that rather wide ratios were established between the primary cations in the soil as a result of lime and potassium applications. However, the ratios were relatively con— stant for any series of treatments. This would indicate that the presence of a complementary ion or ions had no effect on other ratios. For example, the Ca/Mg ratio was not affected to any extent by potassium fertilization in either of the two years. The significance of these ratios in the nutrition of plants will be discussed later. Crop Yields The yields of all crops were exceptionally low (Tables VI and VIII). This is a reflection of the very low fertility status of the area at the beginning of the experiment. Although soil test values indicated relatively large increases in the supply of avail- able nutrients (Tables III and IV), response in terms of increased growth was not obtained. Such results suggest that the expected THE EFFECT OF SOIL TREATMENT ON THE YIELD OF SEVERAL TABLE VI CROPS GRO'N IN 1955 32 Tons per Acre Bushels per Acre Treatment Timothy hay Soybean hay Millet Soybeans Corn None 0.97“ 0.60 7.5 4.0 24.1 P 0.99 0.80 14.4 3.9 13.8 K 0.78 0.98 9.6 2.8 10.1 PK 0.71 0.97 11.4 2.8 10.3 le 0.76 0.74 10.0 3.8 12.8 LIP 0.70 1.05 14.2 4.2 13.6 LlK 0.70 0.69 13.0 3.7 13.9 LIPK 0.81 1.11 11.9 3.0 10.3 L2c 0.72 0.55 9.2 2.9 23.6 L2P 0.71 1.02 12.4 3.7 14.6 L2H 0.71 0.62 9.6 2.9 17.1 L2PK 0.80 0.97 18.5 3.2 14.8 L.S.D. (.05) N.S. 0.36 5.8 N.S. N.S. 8Average of three IDC’alcitic lime cDolomitic 1 ime replications 33 Hot: 3: «6 3:832:39. 12:: an «o 23:33? NN Masha mo.H an.o 5H.N 80.0 oe.o N aswnudaom x usaosnnosm x saga Ho.u No.0 me.o mN.o ma.o H asumnspom x mzsosnuosm mH.H Hm.o ov.a «m4H bw.u N aaaunsaom x oiuu mn.o mm.o wb.H mw.H OH.O N nahosnmozm x oE«A Ha.v .va.v No.6 om.a eb.o H Isumnsuom em.n nu.o 445v.NH .4Nm.oa no.o H assessment we.H mm.o Hm.o vb.o ns.H N osau mn.~ hm.o .Nn.N 4Nn.N nm.o HA nusoausohs mm.H v¢.N no.0 .am.n 40.0 N nsoawsoaanom . 40.0 an House has as: sovooah :aoo usoonhom «odds: suonhom assess? .mo seawmfiao> no ooasow mosao> & newsman HHHHHHH11 mnAfiH> memo mnaa ho HUZde<> ho mHmwAoa as oo oaooasaawam.. He>oa an 08 00060006000. NN aohhfi Ho.0 00.0 00.0 00.0 05.0 00.0. N 850000060 2 0566000600 a osau 00.0 ma.0 00.0 no.0 00.0 00.0. 2 550008060 2 nauosoooss no.0 00.0 00.2 00.0 00.0 ~0.H 0 asaouooom x ulna 00.0 00.0 00.0 00.0 no.0 sa.a 0 0046000000 x ones 00.0 .00.0 00.0 ..00.HH 00.0 00.0 H . 850000060 ..00.20 00.0 00.0 no.» HH.0 00.0 s 0560000620 ..~0.0a ..00.0 00.0 00.0 00.0 .00.0 m oaaa ..00.n .sn.0 00.H ns.a ~n.0 s0.a as noooaoooos 00.0 ..mm.e~ ..H0.HH ..0¢.0a ..00.0 .00.0 N oaoaoooaaoom on Hones «00.5 .300 ncooamom 00:“: .80me hauwuas somwwfim 003.38; .00 ooh—3m mead; 1m nonhuma— nfifi» 0000 002 .40 00235; 00 300.3: .5 Eng 38 and/or the supply of available calcium were probably of greatest importance. The only significant response to phosphorus applications was by the wheat crop. The average increase in yield per acre with phosphorus additions was 85 percent, indicating the tremendous importance of an adequate supply of available phcsphorus in the nutrition of the wheat plant. None of the interactions between supplied nutrients were statistically significant, indicating that insofar as crop yields were concerned the addition of one nutrient, within the range of amounts applied, did not influence the effectiveness of another. Chemical Composition of Crops Studied Timothy Hay Figures 1, 2 and 3, and Table X, present a summary of the effect of soil treatment on the composition of timothy hay. It should be recalled that these fertilizer and lime applications were made on the surface of the established timothy sod. In both years these applications were made about one month prior to har- vest. In spite of the relatively short period of time involved, certain changes in composition of timothy occurred in 1955. Both liming materials increased the uptake of calcium and magnesium. As would be expected, based on the composition of the two lime- atones, calcitic limestone was most effective in increasing calcium accumulation while dolomitic limestone improved the uptake of ‘Iii‘ / 0.25 / 0.20- / 0.15- 0.10‘ pennant 0.054 Ol_ uh O' 0 Mill iequivalents/lOO grams 8 10‘ p Total p ,/ lpcations /0—-°~.~3 W W: 0 0 9 k fix’b 9 k 43% 0 9 7? PK ‘—— —Ca—M ——r «— +Ca-Mg —-> ‘— +Ca+Mg —" 8 Tig. l. The effect of soil treatment on the composition of timothy hay grown in 1955. o u n 0.30! 0.24- 0 0-18 ‘ Percent 0.12 ' 0.06 1 60- ”HUMMVHIGHts/IOO grams 5? '3." 3 5.; 7.3 g 3' p—a N 40 . ' £13. x 10‘1 Total ,/ Cations N M . _———.——.~ ca 0 P R 9'14 0 13 1'( fix 0 1') 1: Pk "— -Ca-Mg—-D- *— +Ca-Mg —’- *— +Ca+Mg ‘—"‘ The effect of soil treatment on the composition of timothy hay grown in 1956. Percent 11 Percent u 41 1955 Ash )‘""‘{ ” x/o.~~.°’ 1956 I #‘- / ' ”NO—O—fl—‘N G [92" I5. '0 P 14 Pk 0 P' 14 Pk 0 P 14 15K anv— -Ca-Mg -—-m- ‘— +Ca-Mg —-1n- 4.— +Ca+Mg —. The effect of soil treatment on the nitrogen and crude ash content of timothy hay grown in 1955 and 1956. TABLE X 42 PERCENT CHANGE IN THE COMPOSITION OF TIMOTHY HAY AS A RESULT OF LIME AND FERTILIZER APPLICATIONS Constituent Ca-Lime Mg-Lime Phosphorus Potassium 5155 Calcium 43.4“ +10.2 - 9.9 4 7.7 Magnesium +14.6 419.8 +16.8 -— 2.8 'Potassium 4 1.4 — 2.0 + 8.1 +31.8 Sodium -24.3 -48.8 -12.7 + 7.2 Total cations + 3.4b - 0.6 + 7.1 +25.3 Phosphorus + 9.8 + 5.8 +72.9 + 7.4 Manganese -14.8 - 4.9 — 6.6 +20.3 Nitrogen + 5.9 + 2.7 + 3.2 + 6.1 Crude ash + 4.8 + 1.3 +17.8 +17.3 1256 Calcium +39.1 +17.2 + 2.5 -l3.5 Magnesium + 0.6 +29.6 + 5.4 -16.7 Potassium + 5.3 + 5.8 + 9.8 +30.5 Sodium + 2.9 +15.6 + 1.6 + 1.6 Total cations + 6.9 +12.4 + 7.6 +12.0 Phosphorus — 3.4 - 3.4 +45.4 — 3.0 Manganese —29.l -2l.3 +21.8 - 9.8 Nitrogen + 4.5 + 7.9 + 5.9 + 1.7 Crude ash + 2.2 + 1.0 +ll.8 +10.9 aPercent increase or decrease compared to unlined or unfertilized treatments. bCalculated from the sum of the milliequivalents of calcium, magnesium, potassium and sodium. u“ignesium to the greatest extent. Both materials also tended to increase the uptake of phosphorus and decrease the accumulation of manganese. Here again, the trend was most noticeable with the calcitic limestone. This is no doubt due to the greater proportion of fine material in the calcitic lime, resulting in a more rapid dissolution and conversion to the ionic form. Even under condi- tions of equal particle size, dolomite is somewhat more resistant than calcite (Beacher st 21, 1952). The accumulation of sodium was greatly decreased by lime treatment, particularly dolomite. However, due to the very low content of sodium in the tissue this was not reflected in the overall uptake of cations. The uptake of the other monovalent cation, potassium, was unaffected by soil treatment. Since the potassium was applied in a water soluble fcrm it was immediately available for plant absorption. ‘Thus it would be expected that the lime treatment would not exert any substantial effect on the uptake of this nutrient during the comparatively short period of one month. Of all the nutrients applied, phosphorus was the one most effective in increasing the content of that particular ion in the plant. 0n the average, plants receiving applied phosphorus con- tained 72.9 percent more phosphorus than untreated plants. In view of the surface application, and the immobile nature of phosphorus in the soil, this accumulaticn is worthy of note. Three factors probably contributed to this immediate response. First, the form If phosphorus used (treble superphosphate) is largely water 44 BOIbele and hence was available for immediate utilization. Secondly, there was not sufficient time for soil fixation to occur, particu- larly with such a high rate of application (1250 pounds per acre). If the fertilizer had been mixed with the soil, fixation probably would have proceeded at a faster rate. Thirdly, there were no doubt a number of absorbing roots close to the surface of the soil, so that the phosphorus ions did not have time to move any appre— ciable distance before absorption occurred. Phosphorus increased the uptake of magnesium and phosphorus, which contributed to an increase in the crude ash content. Potas- sium absorption was also increased to a certain extent by phosphorus applications to the soil. It is possible that the inclusion of phosphorus resulted in more vigorous root growth, thus increasing cation accumulation. Potassium applications to the soil resulted in a substantial increase in potassium concentration in the plant. At the same time, the uptake of other cations was essentially unchanged so that the increase in total bases was almost entirely due to potas- sium, Potassium also accounted for a considerable increase in the content of crude ash and manganese. However, the manganese content was subject to appreciable variability so that this observation is of questionable significance. The data for the composition of timothy hay grown in 1956 shows several inconsistencies when compared to the 1955 data. CaIC1tic lime increased the uptake of calcium even more than it [ii‘I :1!) 1955. This was probably due to the longer period of time 45 ‘5 during which the lime was able to react with the soil. coupled with the use of hydrated lime in 1956, thus increasing the water soluble and exchangeable calcium in the soil. This conclusion was borne out by the soil analysis data. Similar statements can also be made regarding the dolomitic lime, with a subsequent in- crease in the content of magnesium. The calcitic lime did not increase the uptake of magnesium in 1956 as it did the previous year. This can be accounted for on the basis of a considerable increase in the content of exchange- able calcium in the soil while the level of exchangeable magnesium was almost the same. This wider Ca/Mg ratio in the soil was then reflected in a wider Ca/Mg ratio in the plant. The magnesium content of all samples was several times higher in 1956 compared to 1955. No plausible explanation can be offered for this observed phenomenon. Differences in climate and “other cultural practices, such as nitrogen fertilization, may have contributed to this increase. The total nitrogen content of the forage was similarly increased, which appeared to be unrelated to soil treatment. Liming the soil again reduced the uptake of manganese. The accumulation of manganese by the plant was closely related to soil levels of manganese, although the decrease in uptake as a result of lime applications was not nearly proportional to the decrease in exchangeable manganese in the soil. No doubt the plant secured soluble manganese from sources other than that Id£0rbed on the exchange complex. 46 ; Although phosphorus applications increased the phosphorus content of the timothy, the increase was considerably lower than for the previous year. During the intervening time interval a considerable portion of the phosphorus was probably fixed in a form unavailable to the plant, even though this fixation was not reflected in the soil tests. Manganese uptake was improved by phosphorus applications, although this trend was most noticeable on unlimed plots. Potassium fertilization again accounted for a substantial increase in the content of total bases in the plant. However, the change was less noticeable than in 1955 for several reasons. First, high potassium levels in the soil and in the plant reduced the uptake of calcium, and more particularly magnesium. Secondly, increased magnesium uptake as a result of magnesium fertilization accounted for a greater propcrtion of the increase in total cation content. The fact remains, however, that heavy applications of potassium fertilizer exerted the greatest effect on cation accumu— lation, both in terms of ratio and absolute quantities. At any particular potassium level there was a marked tendency for the sum of the other cations to equal a constant. Soybean Hay As seen in Figures 4 and 5, the cation content of soybean plants was approximately three times that of timothy hay, indicating that this plant removed many more nutrients from the soil than did the timothy. , 47 1. /’°\\ / ‘0 ma [9’ 1 / /R\ o 6. ’ / \ °K . / / \ \ .2:- / / \o\ \ 8 / / \\ \\ a .- ~ - g o 4 J c! \o \\°’ "fin x 10 1 0.2 '////.‘~§‘.”/" '/’//m\\\\‘//,/fi ‘////A\\\\"”,a p 0.0 - ‘ ‘ - 140‘ I R x] \\ T t 1 ‘ .n \ _ o a / \\‘t{/ \3 R )3— ations / \ / 120' ”I \ I a, , \ I \ , v ‘ I \a’ n 5100. Eb o 1 -.O H E 80‘ Q E w d H m -: 60 ' a S u o I fl 3 £40. o———--o\ V/K\ :8 VA\/%L Ms ‘ ’Fo‘fl Ax a’g— I, \%K 20. A‘“ “‘4’ A“-~A/ o P K in 6 13 T< Pk?) F 1% PR 4— -Ca-Mg —o- ‘— +Ca-Mg —— 4.— +Ca+Mg —m~ 4!. The effect of soil treatment on the composition of soybean M ' hay grown in 1955. ’13.: :1. . . 0.6- °\\0’/ 0.4- °\ , \ 0" ‘0\\ we \ ”(K = . \ \ o I \ 00.2 °' -1 ‘ Mn x 10 0", ‘ I I I l 4- A l a m l 180. '4‘ I I ’A\ gr \\ A 160‘ I, \ \x .n / \ d h‘s hf” I \ ‘ ‘U / \ 1404 J “*3 a Total 5 . Cations Q20- 0 o 1 F4 hoo- +1 a d o '3 so. 2, s 4 a 3 60 'H I 2 . 0’", \ z’41\ « ‘\a 0" \~ M 5 /‘o\ ‘0\ ‘°——'0 5 40% 0’ \\°___ \0 l3 -—A A“ 20 '2’ / ’ \A K ' a———y ’ A-“r-J L‘~A/ c i V V j V *7 1 fi' 37 E T 0‘— I:Ca-Mg _._PK 9‘— ECa-MK ”PK 0“— +Ca+Mg _._PK 55. The effect of soil treatment on the composition of soybean fl?“ hay grown in 1956. 4 9 =' '4'” 1955 71 /p"" 0‘ / \\fi P~\\°A8h 6 ’ ‘\°/ °~ ’ w o~ / \\ / “4 ‘0’ 5‘ g «a a c: i'h 3 5' $.4‘ l d‘.’ £;. 34 ”\H "\ ./////.———_—.————‘. - N 2% 1. o. J A __l A m l A l A __m m I 1956 .- —- lax 8‘ /’0— ‘0— -° V’IA‘ /’° ” \\ Ash V/ ‘\o,’ 0’ ‘O—--O 6* a a a U ‘6 93‘ e/////*_~_‘."’—‘. ’—_* 3 i3~———. N 2i 0 w ofD 191615 Erica? {71c «m— -Ca-Mg —o- 4— +Ca—Mg —+- ‘— +Ca+Mg —-'- Fig. 6. The effect of soil treatment on the nitrogen and crude ash content of soybean hay grown in 1955 and 1956. i... 1 .I: .1. PERCENT CHANGE IN THE COMPOSITION OF SOYBEAN HAY AS A RESULT OF LIME AND FERTILIZER APPLICATIONS TABLE XI Constituent Ca-Lime Mg-Lime Phosphorus Potassium 1.9.52 Calcium +16.la + 9.1 - 8.3 + 2.9 Magnesium +12.0 +10.7 + 2.8 -12.5 Potassium - 6.3 - 9.2 - 6.4 +47.7 Sodium + 5.9 +16.9 — 5.4 0.0 Total cations + 8.9b + 4.7 — 4.7 + 7.0 Phosphorus + 6.9 + 2.3 +44.0 - 6.5 Manganese -36.8 -44.3 +16.1 - 1.8 Nitrogen + 8.9 + 5.5 + 3.1 ~ 5.2 Crude ash + 2.5 + 0.5 — 4.6 + 5.8 1.2.5.9. Calcium + 0.7 -l4.8 +10.8 -19.3 Magnesium +17.3 +18.7 + 5.4 -18.6 Potassium - 6.0 -11.5 - 5.4 +99.0 Sodium - 8.5 -23.7 - 5.6 0.0 Total cations + 3.9 - 5.7 + 5.5 — 8.0 Phosphorus +10.5 + 2.3 +29.0 + 2.2 Manganese -50.8 -47.1 — 8.8 -ll.7 Nitrogen +10.5 + 5.9 - 1.8 - 4.1 Crude ash - 0.8 - 1.5 + 6.9 + 0.5 aPercent increase or decrease compared to treatments. bCalculated from the sum of the milliequivalents of calcium, magnesium, potassium and sodium. unlimed or unfertilized Both liming materials were more effective in increasing the calcium and magnesium content of soybean plants in 1955 than they were in increasing the uptake of these same elements by timothy “Table XI). As already indicated, this is related to the length (If time from date of application to harvest, and the low solubility f? «of lilmstone. The uptake of calcium was somewhat proportional to §1 “the cmncentration of calcium in the two materials and the level «if exchangeable calcium in the soil. Hence, the increase in cal- cium ion accumulation was only one-half as great with dolomitic ’ lime compared to calcitic lime. Both materials gave small, almost identical, increases in magnesium uptake. This, too, was reflected in similar soil levels of available magnesium. Lime applications reduced the uptake of potassium to a slight extent. The concentration of manganese in the plant was also reduced considerably by lime treatment. 0n the other hand, ' sodium uptake was increased by lime treatment, although in terms of absolute amounts, the increase was small. Phosphorus in the plant was closely correlated with avail- able soil phosphorus. Manganese absorption also appeared to be increased by phosphorus applications. Small, but probably insig- nificant decreases in calcium, potassium and sodium uptake accom- panied phosphorus accumulation. Potassium fertilization resulted in almost a 50 percent increase in the concentration of this ion in the plant. Part of this increased potassium uptake was counteracted by a decline in magnesium absorption. This is in agreement with the work of 52 Prince e_t_ _a_l (1947) who noted that the quantity of available potassium in the soil was the most important single factor influ— encing the magnesium uptake of plants. Potassium also decreased the nitrogen content of the soybean forage (Figure 6). This ap— peared to be an indirect effect confounded with lime treatments. In the absence of lime, potassium did not decrease the nitrogen content of soybean hay. In 1956 calcitic lime failed to increase calcium uptake but did improve magnesium accumulation. This increase in magnesium concentration was almost equal to that obtained with dolomitic lime. There is no apparent reason for these conflicting results. Calcitic lime also increased the uptake of nitrogen and phosphorus, probably due to its effect in increasing the pH, thus creating a more suitable environment for nitrogen fixing bacteria and a more desirable soil reaction for phosphorus solubility. Truog (1951 ) has shown that phosphorus availability is higher on neutral t0 Slightly acid soils than on those which are strongly acid. The increased absorption of magnesium as a result of apply— ing d01omitic lime occurred at the expense of calcium and potas- Silfll uptake. However, the total reduction in cation accumulation was almost 17 milliequivalents per 100 grams, while the increase in magnesium uptake amounted to only 7.5 milliequivalents. As in the case of timothy, applied phosphorus resulted in a smaller increase in the phosphorus content of the tissue in 1956 samples. However, it also decreased the accumulation of calcium in the plant. The potassium concentration in the soybean plants was almost doubled in 1956 as a result of potassium fertilization. This ef— feet was coupled with a substantial decrease in the calcium and magnesium content, so that the total cation concentration was re- dUCEd by the presence of high amounts of potassium in the soil. This Was in contrast to the large increases in the cation content of timothy hay attributable to potassium applications to the soil, With a subsequent increase in potassium absorption. Mill e 1: Grain Data for the composition of millet as influenced by lime and fertilizer treatments are graphically shown in Figures 7, 8 and 9 - It is evident that millet, like many other seeds, is very low in calcium so that small changes in the content of this ele— ment may be relatively large when expressed as a percentage of the total . In 1955 neither of the limestone materials changed the calcium content, but both gave about a fifty percent increase in masnesium (Table XII). This is no doubt a reflection of the select- ive exclusion of calcium by the millet seed. As observed with other crops, lime applications depressed the accumulation of man- ganese substantially. Total cation content was also increased by about. one-third, primarily as a result of increased magnesium in the seed. Phosphorus applications to the soil were less effective in increasing the phosphorus content of the tissue than they were in the other crops previously discussed. Small increases in the w y. 1.3:... 54 0.5‘ P\\ 0.4. I, \E 'N/ w I \\ \AP 0.3. / / \o a / / D 5 ‘d I I .— 2 0"" I // Mn x 10 g 0.2‘ q I /0—---o’ \ I 0” \ I 0.1« \l o ‘ A A I I l I A 201 I, \\ / \3 //°Total 18‘ u\ I, // Cations \‘fl D-—--a\“‘( 16‘ I \\ IF I \ ll 14' / \ , L \ / 0’ °\ \ f / 4\ \ L0 E Q A w o o i .310- “I § /\ f \ / , 455+ / X/A HG‘ A‘u " pa--- v knew-Ax 44 21 o——o—-——-‘°"—4 ._*____.~. M 4 0 ' 1'( PK oexpfifii’kpkbp ._ —. «— —~ *- 7; Fig. 7. The effect of soil treatment on the composition 0 m grain grown in 1955. 55 1.0. ‘ ,0 l/ 0.8. If ’9“ \ / I 0.6. °___4 o. / a s‘d q ‘2 5 . \ Mn x 10 500.4. N \ /D’” P 9: 1 N \b” 0.2.4 a I a A n A: ‘ g t 1 o a R {I/ \ [eations I \\ \ / 24‘ I \ )3 \ [I I, \ // \V \ I \ / /A\ / I! am ur/ \Nr’/a £1 H 73 l H I9 1 Milliequivalents/loo grams 0 o—_.—d-——* .—.———O——-0 . a Fig. 8. b F k 31? 6 F it fik 6 I5 K FIE «— -Ca-Mg —' <— +Ca—Mg —' ‘— +Ca+Mg —> The effect of soil treatment on the composition of millet grain grown in 1956. 56 1955 :3 a //’°-~~ ___0 [IA ”A811 « -.. - , \isix N E 2 \/.\. 0' 1. o A j I l J 41 A 4 ‘ A A J 1956 :5 ffish o————4r————O\ I /A\ ”o w I \ r , ~-o-—- / N W V ”A\ I 0’ \\ I 2 \d’ 4.: a a o a 0 On 1 i o - e - o p 1( PK. 0 l’ 1K PK b ‘5 if fik «a— -Ca-Mg—-'- Q— +Ca-Hg —-o- *— +Ca+Mg -—-v- Fig. 9. The effect of soil treatment on the nitrogen and crude ash content of millet grain grown in 1955 and 1956. h TABLE XII 57 PERCENT CHANGE IN “IE COMPOSITION OF MILLET GRAIN AS A RESULT 0]“ LIME AND FERTILIZER APPLICATIONS —— Cons t ituent Ca-Lime big-Lime Phosphorus Potassium £52 Calczlum - 3.7a - 2.7 + 6.7 + 4.1 magnesium 450.1 451.1 +15.2 + 9.7 Potassium +15.5 - 0.9 - 0.4 + 4.0 Sodium - 8.5 + 4.2 + 2.6 + 2.6 Total cations +33.9b +28.4 + 9.1 + 7.3 Phosphorus + 7.1 + 2.3 + 7.2 - 1.4 Manganese -25.2 ~35.4 - 6.7 +72.6 NitI‘Ogen + 6.7 + 6.7 - 7.0 - 2.3 Crude ash - 6.4 —- 9.2 + 8.8 + 5.2 $25.6 .- Calc ium +20.3 + 4.0 +14.6 + 1.6 flamesium +21.8 +52.5 +17.4 - 7.5 Potassium + 2.5 + 1.0 +ll.7 + 6.0 Sodium - 1.6 + 0.8 + 2.4 - 7.5 Total cations +13.1 +27.6 +30.5 - 2.0 Phosphorus - 0.9 - 3.7 +26.8 + 4.5 Manganese -l4 . l -43 .4 --11 .0 +24 .4 NitI‘Ogen + 8.7 +13.1 - 3.6 - 1.2 Crude ash - 2.0 - 4.9 412.3 + 2.5 —_—i aPercent increase or decrease compared to treatments. b magnesium, potassium and sodium. unlimed or unfertilized Calculated from the sum of the milliequivalents of calcium, x-uvn ad" ".1 58 ‘3’" crude ash and calcium content, and an appreciable increase in magnesia. uptake could also be attributed to phosphorus fertiliza— tion. with the net result that the total cation content of the millet seed was increased by almost ten percent. Potassium applications did not affect the composition of :7“ the millet to any significant extent, with the exception of. man- f +11 E l Sanese , which was increased. The increased magnesium content of w t the tissue which had received potassium fertilization was contrary "a t0 observations with other crops. The further application of lime in 1956 increased the uptake of calc ium where the calcitic material was used. It should be re- ‘e'bered that the lime applied in 1956 was hydrated, thus a faster reaction in the soil and a subsequent increased uptake by the Plant could be expected. Magnesium uptake was also increased by the ca-1<:itic lime, but not nearly to the extent it was in 1955. Dolomitic lime again caused a fifty percent increase in the ¢€\Snegiu. content of the millet. However, it had no effect in the “cc“‘ulation of calcium, potassium or sodium. Both materials in- creased the nitrogen and total cation content of millet seed and decreased the manganese. Dolomite was most effective in bringing about these changes in composition. In both instances the increase in total cations was almost entirely due to the accumulation of additional magnesium, especially in view of the wide Mg/Ca ratio in millet. In 1956 phosphorus applications to the soil increased the crude ash, calcium, magnesium, potassium and total cation content 01' millet seed, apart from a substantial increase in the accumu- lation of the phosphate anion. Manganese concentration in the tissue tended to be reduced by phosphorus treatment. The effect of potassium fertilization on the composition of millet grown in 1956 was similar to results obtained in 1955. There was a general lack of any consistent change in the content 01' the various plant constituents, with the possible exception of unganese which was increased. Whereas potassium tended to i"(Brease magnesium absorption in 1955, the reverse was true in 1956 . 32mm Grain Table XIII shows that lime applications in .1955 did not. change the composition of soybeans to any extent. Calcitic lime tended to decrease the content of most constituents, although this trend was very slight. Dolomitic lime had a similar effect, with the e3‘ception that magnesium and sodium contents were increased a 3‘31]. amount. Phosphate applications to the soil also produced very little change in seed composition, aside from an increase in the phos- phorus content and a decrease in the manganese content (Figure 10). Potassium treatments increased the manganese and crude ash in the soybeans but had no other effect (Figures 10 and 12). .--f-‘ "-7“ "3"?“ .‘f‘ . ». ,' u I.' ,, __._-;_._}J. *fi—f' E‘ .I -_... _-‘~ ._‘.— ..-. ‘ ~. I A: 1‘ ‘. . to a 1". xA‘x /A\ .0— Mn x 10"1 0. I \w / \ ” -- 0.1 m l I 1 1 1 l n 1 1 70 q A___aTotal ‘\ A n~ /’ Cations \ // 6° \( 50 % A‘-_~L.- A K / ‘6 k‘ ")’o m 40 *9. \\ I, \W g V \ Q "E so Q ‘ H § > . «A 3- 0 20. ’0"—.O__' 3 ‘°—'-'°’ o——-o—-——-o\\ 0H 1 .0 S 10‘ W W M Ca o 13 I? Bic 6 1; it 1712 d 15 1% mi ‘.-— -Ca-Mg——-m- -<-— +Ca-Mg —" *" +Ca+Mg—" Fig. 10. The effect of soil treatment on the composition of soybean grain grown in 1955. . .n’“\.'.‘- .33 , . . M. H m.‘lfi‘~..fia V"- _‘ a L‘. Percent 0.31 0.2‘ A ’/ “~o 1 0.1 o _0/ °____°\ m“‘q,,4\‘&nox 10 . n A A I I I ‘W--4 A m A I 70 o\\\ Total ‘ ‘13—”A“ k I’DCations ‘D / \‘NO I / / _./ °\ ’ 60. D--" \\ [I Y 8! M11 1 legal valents/IOC grams 3 r i: .L r | a ‘~W 30' ’0“; 20! 0‘_°__ I ‘0 _ /D - °___ 0 _.4r— *5 4. o 0 a o D- . 2 0<—‘ m l A l J A m L m 4 m 1956 0‘ /A\\ ’A\ I, \ ‘ / ‘0 ’ \ / ‘0 Ash °___,-a°’ / \b / a ’,1 o---d a 4‘ 0’ o o a o E . 2' C) 6 in k in b 13 ft Pk o P K PK F1 ‘— -Ca-Mg —'- ‘— +Ca-Mg —* ‘— +Ca+Mg —’ 8' 21:3. The effect of soil treatment on the nitrogen and crude ash content of soybean grain grown in 1955 and 1956. R. TABLE XIII 63 PERCENT CHANGE IN THE COMPOSITION OF SOYBEAN GRAIN AS A RESULT OF LIME AND FERTILIZER APPLICATIONS Consti t. u e n t Ca-Lime Mg-Lime Phosphorus Potassium .122 Calcium: — 9.2a - 3.6 - 5.1 - 0.8 Magnesium- - 8.1 + 4.9 - 0.8 - 1.7 Potassium- - 0.2 + 1.3 - 4.2 + 4.2 Sodium + 2.9 +15.6 + 1.6 + 1.6 Total cations - 3.2b + 1.9 — 3.3 + 2.1 Phosphorus - 1.3 - 3.6 +16.7 - 0.9 Manganese - 4.3 — 5.1 -12.8 426.8 Nitrogeri + 4.3 + 0.3 + 5.5 + 1.4 Crude ash - 3.6 - 5.8 + 3.3 + 2.5 .1222 Calcium .. 3,2 — 1.4 — 0.9 - 6.2 Magnesium + 0.4 + 2,1 - 3.2 + 7.0 Potassiu‘ 40,3 -12.9 - 1.9 + 9.7 Sodium - 17.6 _ 2.7 - 2.3 - 2.3 Total cations _ 7.0 - 7.5 - 2.2 + 7-5. PhosphOrus - 4.4 - 1.7 +25.8 + 4.6 “any-“ease -61.9 -44.1 -15.0 +16.6 NithEn + 6.9 + 5.7 + 1.6 - 5.3 Crude as]! .. 5,8 - 2.2 — 4.2 \ B‘Percen treat“tents +16.9 1: increase or decrease compared to unlimed. or unfertilized Ezlculated from the sum of the milliequivalents of calcium, 5“esium, potassium and sodium‘. . sfhlq. ...__- s H“ .l‘ _ _,.,._-4__ ‘4‘... ' _. 64 ,; As shown by Figure 11 both liming materials decreased the accumulation of potassium and manganese in 1956. However, values for total calcium and magnesium in the plant were essentially unchanged - Phosphorus and potassium had the same effect on composition in 1956 as in the previous year. The former increased the accumu- lation of phosphorus and decreased the manganese content while the latter increased the manganese and crude ash content. Potassium in the seed was also increased to a small extent by potash appli- cations to the soil. There was a marked tendency for the composition of the soybean Sra in to remain constant, particularly as far as the major cations Were concerned. This trend was consistent for both years indicating that the soybean seed is not materially affected by Unbalanced soil fertility levels. Corn Grai n K Col‘n grain is characterized by a small accumulation of cations, especially calcium. For this reason, small variations in CompositiOn, although not readily apparent, may be 0f very real importance in determining the nutritive value. In 1955, liming the soil did not increase the accumulation 0f calcium: in the corn grain (Figure 13). Magnesium absorption, however 3 was increased by applications of dolomitic lime, but not 65 0.4- P 9' Percent O '? 0..l‘ 04* A g 4 A A A A A A A . 24‘ P / / - / R\ / F\\ 20. I \ / P l/ ‘0. l \ / / / \‘fl / \r‘ / / Total ' . / D- " ”R / d Cations cf \\ ., / \ / H 02 l (K A p... P “P. \\\ >5 /\ Milliequivalents/IOO grams g v _A r A k A a fi‘ : - 4. 4Ca o P x PK 0 P x Pk? b in PR F1 ~«m— -Ca-Mg—'"' ‘— +Ca-Mg —'- ‘— +Ca+Mg —- 8’ 13. The effect of soil treatment on the composition of corn grain grown in 1955. l“ 66 Percent 84 Milliequivalents/IOO grams \::>D “o \\\§g m V ‘ V I v P K PK C) P K PK () P K PK «e— -Ca-Mg --—e «a— +Ca-Mg —o- *—-- +Ca+Mg -—p- 14. The effect of soil treatment on the composition of corn grain grown in 1956. ' iFigH 67 I 1955 24 .////"“~ov”" ““~m\\\\.////‘ ,_—_—m~‘-._-_‘ N ,9 2: . A /’° a--. / AA. ”AAA o ‘ I \ / /’ ‘ a // \IY \\ I 0’ ‘0’ g 0’ ‘0’ ll 01‘- 4 j 4 4- ‘ A m 4 A A 1956 2 N W’A [p r; S ' N ‘o’ H a o 0 a o D. 1. obkp'xdfikpk'o‘p‘xfai Ex ‘— —Ca-Ms —.- «m— +Ca—Mg ——t— +— +Ca+Ms —. X‘ X5. The effect of soil treatment on' the nitrogen and crude ash content of corn grain grown in 1955 and 1956. I I 'l\ TABLE XIV 68 PERCENT CHANGE IN THE COMPOSITION OF CORN GRAIN AS A RESUIT OF LIME AND FERTILIZER APPLICATIONS n Can. t i tu ent Ca-Line Dig-Line Phosphorus Potassium lflfi Calciu- 0.0a — 2.4 — 3.0 - 3.0 lagnesiun -1l.4 + 9.9 +20.2 - 7.5 Potassium - 7.8 -11.5 +13.7 +14.5 Sodiu- 457.5 -55.7 -18.9 +28.4 Total cations - 9.9 - 1.9 +16.l + 2.9 Phosphorus + 0.9 + 1.5 +40.0 - 1.5 Manganese - 2.8 + 3.2 +304 +15.5 Nitrogen + 0.5 - 2.1 + 3.2 - 1.1 Crude ash + 4.1 - 3.4 +18.0 + 1.2 .1152 much“. -11.1 -l4.8 -11.5 - 4.0 Hague-31... + 9.2 + 8.3 +33.2 - 1.5 POtassm- — 0.9 + 3.3 +11.8 + 1.6 swim-I- - 1.7 0.0 +2o.4 - 6.5 Total cations + 3.8 +12.4 +17.9 - 4.5 Phosphorus + 1.8 + 3.5 +37.6 + 3.9 Manganese -23.2 -35.9 0.0 +14.5 NitrOgen + 1.6 + 1.6 + 2.7 0.0 crude ash + 5.1 + 1.7 +1332 - 2.7 \ a::::ent increase or decrease compared to unlined or unfertilized b tuents. ce1?u1ated fro. the sun of the milliequivalents of calcium, mag- 81l-IIII.. potassium and sodiug. calcitic lime. Both materials reduced the potassium and sodium content . The net effect of adding lime to the soil was to cause an appreciable decrease in the measured cation content (Table XIV). The applied phosphorus, aside from substantially increasing the phosphorus content of the grain, increased the accumulation of magnesium, potassium and manganese, but decreased sodium uptake. The total cation content of the grain was increased about 14 per- cent by phosphate fertilization. It is suggested that increased absorption of phosphorus may have stimulated the physiological PrOCesses in the grain in such a manner that the requirement for the Other cations was similarly increased. The calcium content of the 81'8 in was not increased. Perhaps the element is selectively excluded by the corn grain. Potassium fertilization increased the accumulation of P°taSBium, sodium and manganese in the'corn, but decreased the Illa8"eE-i\.lm content to a slight degree. It is interesting to note, h°'°Ver , that the increase in potassium in the grain due to high lev\x_]_s of potassium in the soil was slightly less than the potassium accumlation due to phosphorus fertilization. Figure 14 shows that the calcium in corn was actually reduced by line applications in 1956. Although such a result might be ex- pected when a high magnesium lime is used, it is contrary to expec— tations for a high calcium line. This fact further leads to the co nclusion that calcium is selectively excluded from corn grain. A part from a small increase in the magnesium content and the usual 70 reduction in manganese, liming had no further effect on the compo- sition of corn grown in 1956. The effects of phosphorus applications on the chemical com- position of corn grain grown in 1956 were very similar to those obtained in 1955. Phosphorus, potassium, magnesium, sodium, crude ash and total bases were all substantially increased in the kernels while calcium was decreased (Figures 14 and 15). The increase in the nag-nesium content was most striking. Total cations were in- creased by 18 percent as a result of phosphorus fertilization. It is very evident that there was little change in chemical cowosition with the addition of potassium. Even when potassium '33 added singly the accumulation of this element remained un- changed . Whereas potassium decreased the content of calcium, and '°re Particularly magnesium, in timothy and soybean plants, it had “0 effect on these two elements in corn. However, as in the pre- vious year, potassium increased manganese uptake. The data show that the sum of the cations in corn is not equal to a constant. Deviations of over 20 percent from the mean W Only one crop of wheat was grown. Plots which were limed a nd fertilized in the spring of 1955 were fallowed until autumn vh en the winter wheat crop was planted. Figures 16 and 17 present War 1ations in plant composition as a result of soil treatment. 7.....___. . ....3-,...-.. -. v~.-.- ’ n—t II— a.-. , . .. L; ' I Percent Milliequivalents/loo grails 71 O / V \ If \ lea t al \ / Cations ”K ,A /\ ' \ / ,Ax ‘ I . M Na?” ‘ o’ 4” WWW—fica 7) 15 1? find i It Pkb i K Pk FL 4— -Ca-Hg—'- o— +Ca-Mg —-a- 4— +Ca+Mg -—--u- \\ 16. The effect of soil treatment on the composition of wheat grain grown in 1956. 72 2.55 2.() 1.5 Percent 0.5 C) v o i? 1? PK 6 P 1': PK 6 17 R Pk co— +Ca-Mg -—.- ‘— +Ca+Mg ——o- The effect of soil treatment on the nitrogen and crude ash content of wheat grain grown in 1956. Fig. 17. j" RESULT OF LIME AND FERTILIZER APPLICATIONS —# L v—v TABLE XV PERCENT CHANGE IN THE COMPOSITION OF WHEAT GRAIN AS A .— gr Cons t 1 tuent (Ia-Lime Mg-Lime Phosphorus Potassium M Calciu- — 0.5b 48.5 - 4.3 — 8.2 Hague-sium +41.5 41.7 4. 5.8 ~24.6 Potassium + 2.1 + 1.1 +14.9 t 4.9 Sodiu- 46.3 48.7 - 2.7 - 2.7 Total cations +21.8c - 6.6 + 9.0 42.8 Phosphorus .11.? + 8.7 +41.3 + 8.0 “meanness 47.5 -20.3 +35.6 43.3 Nit-roses . 4.4 + 5.8 -15.6 - 1.9 Crude ash 40.9 +27.2 + 6.0 +lO.9 a “eat planted in fall of 1955 and harvested in 1950. Perecent increase or decrease compared to unlimed or unfertilized t"eatments. c calculated from the sum of the milliequivalents of calcium, ‘aSnesium, potassium and sodium. Table XV illustrates the average change in composition resulting from line and fertilizer applications. (:alcitic lime increased the magnesium, phosphorus, crude ash and total cation content of the grain while reducing the accu- mulation of sodium and manganese. Calcium in the wheat was also 3"“- slightly decreased. The largest increase in magnesium content . g occurred where calcitic lime was applied alone, or in combination ! with phosphorus. When combined with pctassium there was no sub- stantial increase in magnesium, indicating that potassium depressed J the magnesium uptake. lJolomitic lime had a similar effect on crude ash, phosphorus, sodium- and manganese. However, in addition, this liming material decreased the calcium and magnesium contents, and thus the total cation content. No ready explanation can be given for these ob- served differences between liming materials. Phosphorus applications to the soil, aside from increasing the phosphorus in the wheat, increased the crude ash, potassium, lllelnSahese and total cation content. However, total nitrogen in the grain was reduced by these treatments. (Figure 17). Potassium fertilization resulted in an increased uptake of manganese and a decrease in the magnesium and total cation content. Calcium was decreased to a small extent. It is evident from these data that heavy potassium fertilization of wheat had the same g.enel‘al effect on plant composition that was obtained with the at her seed crops, millet, corn and soybeans. 1- 75 Cation Ratios in Plants The ratios, Ca/Mg, Ca/K and Mg/K in crops grown in 1955 and 1956 are presented in Tables XVI and XVII, respectively. These ratios should be compared to the same ratios calculated for the cations in the soil (Table V). The ratios point out several important factors. Although differences in the ratios did occur with soil treatment, the ratios in the plant were not necessarily related to those found for soil nutrients. For example, the Ca/Mg ratios in millet, soybeans, corn and wheat were relatively constant irrespective of soil treatment. However , in the soil, three to fourfold variations occurred. Simi— 18" Statements could be made regarding the Ca/K and the Mg/K ratios, although the latter is probably more closely correlated to soil values than either the Ca/‘Hg or Ca/K ratios- This lack of a good relationship between the soil and plant ratios is the result of several fundamental facts. First, and pr°bab1y most important, is the selective absorption of certain cations by different plant species and plant organs. This factor "5‘11 be discussed more fully later. Secondly, a whole series of. 81.11% values can be obtained from entirely different experimental “Haitians, The complementary ion effect is relatively more important in determining final plant composition than it is in establishing the absolute level of associated cations in the soil solution or on the exchange complex. Too, with crops such as corn which are very low in one particular cation (calcium) a substantial percent in erease or decrease in the con-tent of that ion will not be reflected A /. — ‘r V —- 'm._' TABLE XVI THE! IBFTECT OF SOIL TREATMENT 0N CERTAIN CATION RATIOS IN CROPS GROWN IN 1955 76 Ratio ~Lim£ Treatment Fertilizer Treatment -Ca-Mg +Ca-Mg +Ca+Mg —K +K Timothy hay Cal/Ms 0.83“ 0.84 0.76 0.74 0.84 Ca/K 0.10 0.11 0.11 0.12 0.09 Ms/K 0.12 0.13 0.14 0.16 0.11 Soybean hay Cal/Ms 1.61 1.67 1.59 1.50 1.76 Cid/K 1.70 2.11 2.04 2.37 1.65 Ms/K 1.06 1.26 1.29 1.59 0.94 Millet grain cal/Ms 0.06 0.04 0.04 0.05 0.05 Cal/K 0.09 0 08 0.09 0.09 0.09 Ms/K 1.43 1.85 2.18 1.77 1.87 Soybean grain cams 0.35 0.35 0.32 0.34 0.34 Cal/K 0.15 0.14 0.14 0.15 0.14 “S/K 0.43 0.40 0.45 0.44 0.41 Corn grain ca/Ms 0.03 0.03 0.02 0.03 0.03 Ca/K 0.03 0.03 0.02 0.03 p.03 "S/K 0.98 0.94 1.22 1.16 0.94 \ a calculated on the basis of milliequivalents per 100 grams. TABLE XVII THE! IEFTECT OF SOIL TREATMENT ON CERTAIN CATION RATIOS IN CROPS GROWN IN 1956 77 Lime Treatment Ratio Fertilizer Treatment -Ca-Mg +Ca-Mg +Ca+Mg -K +K Timothy hay 041/11; 0.38“ 0.52 0.34 0.40 0.41 Cit/K 0.13 0.17 0.14 0.18 0.12 Ma/K 0.34 0.33 0.42 0.46 0.29 Soybean hay CHI/Ms 2.30 1.97 1.65 1.96 1.95 Cal/K 3.80 4.07 3.66 6.37 2.58 Ms/K 1.66 2.07 2.20 3.25 1.32 Millet ggain Cal/Ms 0.07 0.07 0.05 0.06 0.07 Cal/K 0.08 0.10 0.09 0.09 0.09 F's/K 1.16 1.37 1.75 1.53 1.33 Soybean grain “V": 0.28 0.27 0.28 0.30 0.26 M 0.13 0.14 0.15 0.15 0.13 “S/K 0.46 0.52 0.54 0.51 0.50 Corn grain “V“: 0.03 0.03 0.04 0.03 0.03 CVK 0.03 0.03 0.04 0.03 0.03 Ms/K 1.11 1.06 1.01 1.07 1.04 Wheat grain ca/“s 0.10 0.06 0.09 0.07 0.09 C‘VK 0.11 0.10 0.09 0.11 0.10 N's/K 1.19 1.65 1.04 1.51 1.08 ___‘__‘___ a l C c“lated on the basis of milliequivalents per 100 grams. I r in the cat¢i<>n ratio when compared to an element which is accumulated in relatively large amounts. Filltilly, a wide range of cation ratios in the soil and in the plan‘: ‘will result in the same final yield. This fact is sup- POPtEd‘bBV yield data in this experiment. Hence, it is still neces— sary to liliow the absolute levels of an ion in the soil and in the plant 1!! <>rder to interpret the significance of any particular ratio. 79 .v’; DISCUSSION One of the primary purposes of this investigation was to determine the effect of unbalanced fertility levels in the soil on the Chemical composition of several species of crops. It is knc-wn that species vary widely in their ability to accumulate ions depending on the stage of maturity of the plant, the type of ion studied and the part of the plant analyzed. It will be noted from the data that timothy and soybean hay crops: in which the vegetative portions of the plant were analyzed, tended to accumulate all cations to a considerable extent when “"389 nutrients were applied to the soil. Although the data are a“ consistent in all cases, it is evident that calcium, magnesium and potassium levels in the plant were directly related to avail- able Supplies in the soil. Only the magnitude of the increases varied . 0n the other hand, the cation content of the seeds of various species 1 corn, millet, soybeans and wheat was only slightly af- fected by soil treatment. The notable exception is magnesium which was accllllulated by millet and to a lesser extent by wheat and corn. There is considerable evidence that seeds tend to maintain a relatively constant composition (Arnon and Hoagland, 1943; Norman, E 1905). This conclusion is substantiated by the data in the present study. Duncan (1955a) drew similar conclusions from analyses 0f L—i 80 ,3; a number of Species. However, unlike the present investigation, he used balanced soil nutrient levels for plant growth. The mechanism by which plants tend to exclude additional nutrients from reproductive organs beyond those quantities neces- sary for normal metabolic processes is not clear. However, Loehwing (1951) has suggested that it may be due to the formation and tran810catior. of growth substances within the tissue during the initiation of the fruiting process. Actively growing tissue, such as that present in an en- larging seed, requires adequate amounts of nutrients. The extent t0 Which these nutrients are present in the vegetative tissue, or in the soil in an available form, will determine the ultimate size and “Unbers of seeds. If the nutrient supply in the vegetative portion is sufficient, considerable quantities of inorganic elements can be diverted to the reproductive organ, so that the additional requirement placed on the soil may not be great. This is particu- larly true of nitrogen, magnesium, phosphorus and potassium which are relatively mobile in the plant and can be reutilized. However, calcium is much less mobile in the plant than the above elements 8° the-*— supplied for the last formed plant parts (i.e. , reproductive organs) llust come from the soil solution. Phosphorus was accumulated by seeds more than any other element - Apparently the mechanism by which cations are excluded from reproductive parts is inoperative as far as anions are con- cerned s or at least it seems true for phosphorus. Seeds are usually higher in phosphorus than vegetative parts (Morrison, 1947)- 81 I i However, much of this phosphorus is in the form of phytin which is not readily digested; hence many plant materials, although they may be rich in phosphorus according to their chemical analysis, are 9001‘ Sources of phosphorus in the diet (Anderson, 1947). whether or not the additional phosphorus taken up by seeds is actually necessary for metabolic processes is open to conjecture. This hYpothesis would presuppose that additional quantities of cations wculd also be required to satisfy the needs created by an increase in growth reactions. Albaum (1952). in outlining the role °f PhOSpborus in the metabolism of plants, concluded that phosphorus probably affects growth by participating in a number of processes at the cellular level. These include respiration and the subsequent Utilizat ion of carbohydrates. If these reactions are interfered With dUe to a lack of phosphorus, secondary changes may occur such as inhibition of salt uptake, nitrification, and loss of chlorophyll. In the present study, additional quantities of magnesium and potassium were absorbed by corn, millet, and wheat grain, along with increased phosphorus. Whether this is a direct effect result- ing froIII increased respiration with a subsequent increase in ion accum] ation is unknown. The lack of such a trend in soybean - grain 9 and the absence of an additional calcium requirement in all seeds eKcept millet, leaves the subject open to debate. In general , all nutrient elements were increased in the vegetat ive portions of crops used when available levels in the soil were BiIl'aultaneously increased. Hence, it is evident that the root d - , ocs n01; possess the ability to selectively exclude ions, at least .\ ‘ lIIIIfl’l’ l||l.l‘lul|l.lJ to the degree that reproductive organs are capable. However, the magnitude of the change in composition varied with the species, thus leading to the conclusion that morphological and physiological differences in the species are important in determining ion accumu- lation. Such factors as cation exchange capacity of roots, perme- ability Of root membranes, level of metabolic activity, and the innate requirement of the plant are just several of a host of pos— sible causes for such observed phenomena. Since the study of such mechanisms was beyond the scope of this study the selection of a cause or causes would be rash speculation. Macy (1936) developed the concept of a "critical percentage" of each essential nutrient in each kind of plant. Above this Content "luxury consumption" occurs and below it there is a region °f "POVerty adjustment." In the region of poverty adjustment, that 13 -. between a certain minimum nutrient percentage and the critical percentage, yield increases almost proportionately to the increase in percent nutrient content. Below this zone yield in:- creases may occur with increasing nutrient supply while the percent content of that element remains essentially unchanged. Above this zone the reverse is true. An attempt has been made to evaluate this concept with the Present data. Table XVIII presents a summary of the effect of Various nutrients on the content of that element in the plant as well as the effect of these nutrients on crop yields. It should be pointed out that these data are'somewhat arbitrary and hence ar . . e subJEct to certain limitations in their interpretation. The 83 TABLE XVIII A COMPARISON OF THE EFFECT OF LIME AND FERTILIZER TREATMENTS ON THE COMPOSITION AND YIELD OF SEVERAL CROPS Crop Plant C0flosition Crop Yield Ca ‘Mg P K Ca Mg P K l§§§ Timothy my I“ I I I U U U U Soybean hay I I I I U U I U Millet grain U I U U U U I U Soybean grain U U I U U U D U 00m grain U I I I U U U U _1_9§ Ti’mthy hay I I I I U U U U Soybean hay U I I 'I U U U U M“let grain I 1 I U U U U I s°ybean grain U U I U U U U U Corn grain 1) U I U U I U I "heat grain U D I U I I I U '—\ “I: increase, D: decrease, U = unchanged, compared to absence of Of n“trient. p c. ‘ :- ti . - m "' , . __ _ I :1. u II I :h\\ ’ yields are reported as being increased, decreased or unchanged, based upon statistical analysis. The nutrient status of the plant is similarly reported. In the latter instance a ten percent change in composition was considered necessary to warrant the. tabu- lation Of an increase or decrease in that particular element. F“; It would appear from an examination of these data that the E ‘ critical percentage of most nutrients had been reached, that is, where the content of an element increased with no appreciable in— ‘ crease in yield. There are, of course, notable exceptions such as j the increase in the yield of soybean hay in 1955 as a result of Phosphorus fertilization, accompanied by an increase in the phos- phorus content of the tissue. Similar results were obtained with wheat. These observations are characteristic of the zone of poverty adjust-lent, where both yields and nutrient content increase. At the other extreme there are examples of a yield increase but no increase in nutrient content, as illustrated by the effect of ph°3ph0rus and potassium on the growth of millet in 1955 and 1956, respectively. when one considers the absolute yields of these crops the fallacy of these conclusions is evident. All yields were extremely low ind1cative of nutrient starvation, at least for one element. It is l“Ore logical to conclude, therefore, that the nutrient con- tents , at least where no lime or fertilizer was applied, are ac— .tually IIlinimal percentages, and that in most instances the zone Where both yield and nutrient content increase was just b91118 reached. It 13 possible. however, for an increase in nutrient . _ ~ ‘ ,. = .3. ‘ I; v ‘ . - .-'"i‘ I” I 7 " g If - fl " I. ’ ‘ , ' a.ifi-l.- _-l" n...- I 8 5 r 1' content to occur without an accompanying increase in yield. This is one of the greatest limitations to the use of total chemical analyses of plant tissue as an index of the soils supply of nu— trients. Under conditions of unbalanced fertility one or more elements which are in short supply may restrict growth while the _._..—- 1‘ element which is in the soil in greatest amounts is utilized in .., luxury amounts by the plant. Too, a limited supply (or excess) of one nutrient may affect the quantity of another nutrient which a .Vi '- V'."' \. - .1 “IL '1 is taken into the plant. This observation was made in the present investigation, particularly between magnesium and potassium. Another complicating factor is the tendency for many plants to show an almost normal content of a certain nutrient even if the supply is limited. The plant or plant part merely makes the amount of growth which the nutrient supply permits, keeping the chemical composition of the plant tissue almost "constant (Cook and Millar, 1953) . As seen in the present study, this is especially true of seeds . Considerable evidence has accumulated supporting the hyPOthesis that cation uptake by plants is related to the percent base Saturation of that particular element in the soil (Mehlich and Colwell, 194:5, 1946; Meblich, 1946). This is due to the fact that the availability of a cation is dependent on the activity of that ion adsorbed on the soil colloid (Marshall, 1948, 1951). The type of soil colloid is also a factor in determining the activity of an ion and hence its uptake by plants from a given system (Chu and Turk , 1949; Hehlich and Coleman, 1952). 86 a f". Mehlich (1946) noted that the sum of the cations in a par— ticular plant species grown on an illitic soil was a function of the base saturation of that soil. Data in this investigation do not bear out this relationship. Although there was a distinct tendency for the content of any particular cation to be related to the base saturation of that cation in the soil, the total cation content did not increase with increasing base saturation. Since cach 111': and magnesium are the ions primarily responsible for an increase in the percent base saturation of the soil, the failure of the relationship referred to by Mehlich to prevail in the present study is due to a general failure of the plants to take up addi tional calcium and magnesium with an increase in the avail- ability of these cations in the soil. It should be pointed out, however- , that the analysis of entire plants rather than specific parts might have shown entirely different results. A slight, though inconsistent, trend toward increased cation content of plant tissue was observed with increasing bases in the soil. Power (1954) Obtained an increase in the total cation content of alfalfa, soy- beans and oats with increasing percent base saturation in the. soil. Observed differences in the accumulation of nutrients by plants of several species have been attributed to variations in morphology and physiology of roots. Drake and his associates (1951) have related this phenomenon to differences in the cation exchange capacity of roots of varying species, while Graham and Baker (1951) paid particular attention to the quantity of ex- changeable hydrogen absorbed on the root membranes. Hence these 87 H-ions associated with the root surface may be replaced by other cations. Plant roots also show the suspension effect and interact with neutral salts to develop exchange acidity, thus indicating the existence of a cation double layer associated with the root surface. However, these phenomena of absorption and release of various cations by plant roots are not directly dependent on root letabo]. ism, since similar results have been obtained with living and ether killed roots at 0°C and 25°C (Williams and Coleman, 1950). Cation exchange capacity measurements on the roots of a number of species have shown that this value decreases in the order soybeans > timothy > corn) millet > wheat (Drake 2 g, 1951). Matt-30h (1948) stipulated a cation distribution in which the outer layers of a high cation exchange capacity colloid would be more dil‘Ite or of lower concentration than a low exchange colloid. This greater. dilution requires greater relative absorption of divalent than of monovalent cations, since the divalent cation is inserted as the square root in the Donnan distribution (K: Vii-a— ). Thus the higher the cation exchange capacity, the greater is the relative “gorption of calcium over potassium. The data in this study bear out the general relationship. The average Ca/K ratio in soybean plants was approximately 2/1 while in timothy this same ratio was about 1/9. Even wider ratios -fere observed in millet, corn and wheat. However, the selective exclusion of calcium by some of these seeds makes further inter- pretation impossible . The distribution of divalent and monovalent cations as a function of the cation exchange capacity of roots has perhaps been oversimplified. For example, McLean and Adams (1954) found that calcium was bound more strongly than potassium on both mono- and dicotolydenous roots. The strength of this bond was not necessarily related to the cation exchange capacity. However, these measure— ments were made in homoionic systems at 100 percent saturation which does not accurately characterize the normal root atmosphere. The relative absorption of ions of different valence is also affected by the concentration of the ions in the soil and the type of colloid. When cations are at low concentration, divalent 1°“ are absorbed in relatively greater amounts than monovalent ions ”0'“ the soil colloid with increasing cation exchange capacity of the x‘OOts. However, at higher ionic concentrations the valence effect tends to disappear (Mehlich and Drake, 1955). Mattson (1948) concludes that it is only when nearly all the cations exist in an exchangeable state and the plant root colloids must compete 'ith the soil colloids for these cations by exchange that [the Donnan d\%\l‘ibution will be reflected in the composition of plants. Thus, ‘9 this investigation, where high. concentrations of cations were iregent in solution and in solid phase, as well as absorbed on the £011 colloid, the Donnan distribution has limited application in dxplaining observed differences in the accumulation of cations by various plant species. The specific mechanism by which cations and anions are ac- cumulated by plants has been the subject of intensive investigation ,.l|l||' lit-III). l: J 89 by plant physiologists. The scope of these studies, and the number of theories advanced, necessarily restrict a discussion of the ac— cumulation of ions to a most general one. Most theories involve the concept of an ion—carrier mechanism (Lundegardh, 1955; Overstreet and Jacobson, 1952). A generalized scheme illustrating the concept of ion transport from the sur— rounding mtedium (o-level) to the interior of the cell (i—level) has been presented by Lundegardh (1955). .Absorption Translocation Accumulation *A' + n’ + R’—> R‘A' + M‘R'———) R” + R” + WA“ i-level o-leve] R+ and R- are the carrier groups and 14+ and A- are the metal- ‘ lic cations and anions, respectively. The extent to which metabolic energy is involved in ion ac- c““"uJ-filtion is the subject of considerable debate. Lundegardh con- giders that the accumulation of a free salt needs only active accumu- jation of one of its ions. If ions are actively accumulated the ”Cid HA will decompose the carrier complex MR, resulting in free t “A and regenerated carrier HR capable of combining with new \23 ati‘ms‘ The carriers R+ and R- may act as "absorption tracks" in Q iransporting ions from the root surface into plant cells. Lundegardh further considers that the Fe ion in respiratory enzymes affects the anion transport. As an electron moves outward along the enzyme system an anion is transported in the opposite direction. According to the reaction 411+ 4» 4e + 02 = 21120 four anions corresponding to four electrons should be transported for each molecule of oxygen consumed. Anions are therefore actively accumulated while cations are passively dragged into the cell via 11' carriers. Overstreet and Jacobson (1952) made certain observations regarding the nature of ion carriers. They sumarized these as follows : (a) iOn carriers are intermediate metabolic products or closely related substances; (b) the carriers are not stable _i_n Elm-0; (c) they undergo chemical alteration in the course of their carrier function; and (d) they probably function as chelated com- plexes- Different rates of absorption of different ions of the same charge . the unequal rates of absorption of a cation and its associ- ated aDion, and the mutual reciprocal effect of ion pairs can partially be explained on the basis of the Lundegardh hypothesis. JacobSO-n _e_t .‘fl. (1950) studied the interaction between H+ and K+. No abSOrption of K was observed if the IC/li+ ratio was less than 17‘ COmpetition between Na+ and K+ was interpreted as indicating \ single binding compound for these two ions. Overstreet, Jacobson and Handley (1952) studied the competi- tion between Ca+ and K+. The presence of K+ reduced the absorption rate of 0&4“, whereas the presence of Ca“’ in certain concentrations reduced the rate of K+ uptake and in other concentration ranges narkedly increased K+ absorption. They concluded that probably a +4- single binding substance serves CaM and K+l but in addition Ca is effective in the removal of the KR complex from the absorption .-iii in site. The results obtained by Epstein and Hagen (1952) are some- what at variance with the above conclusions. Therefore the carrier substance HR may actually be a single compound with differing af- finities for different cations or it may be a series of quite specific compounds. These studies can be of value in interpreting variations in plant composition, particularly when complemented by the concepts of the distribution of ions between rcot and soil colloids. At low concentrations of a particular ion in the soil, and a balance between ions, normal accumulation occurs. As the concentration of a cation increases (e.g., potassium) the relative activity of the cation also 1"creases in comparison to the othersaturating ions. For ions which are bOund by the same absorption site or binding compound an in- crease in activity of one will result in an increase in the uptake °f this cation to the mutual repression of the complementary ion. This in turn is related to the cation of the roots. Monocotyledons, because of their low cation exchange capacity, and the presence of the D0nnan distribution on roots, would tend to accumulate more potas- 3\\\\ and sodium than calcium and magnesium, especially at low external 0 centrations. Conversely, dicotyledons would tend to accumulate cal- aid“ and magnesium and depress potassium absorption. The net effect of increasing the ion concentration in the external root environment is then a combination of several phenomena; (a) the activity of the ion on the soil colloid, (b) the activity of the ion on the root col- 1 aid and the competition between ions for sites on the absorption mechanism. A further complicating factor is the possibility of an 92 ,_:. absorbed ion enhancing or depressing the removal of other ion- carrier complexes from the absorption site. Based on these facts an approximate, though imperfect relationship between the percent saturation of a particular cation in the soil and the content of that nutrient in the plant should result. The present data bear out this relationship in a general way within the limits possible in such a heterogeneous environment. Many authors have referred to the presence of rather definite cation ratios in plants. Among these studies have been those by Mehlich and Reed (1948) on Ca/K and Ca/Mg ratios, and by Stanford SE Ll,- (1942) on the Ca+Mg/K ratio. As already pointed out these ”“08 are of value in predicting ion accumulation and pointing °“t the competition between ions insofar as absorption is con- cerned_ However, plants will grow over a wide range ofcation ratios. This is evidenced by the wide variations in the Ca/Mg, Ca/K, and Mg/K ratios reported in Table V, with very little dif- ferenCQ in plant growth. If the ratio widens or narrows to the point Where one ion is present in deficient amounts then changes 1“ SPOWth will result. For the most part, the ratios obtained in a present investigation were not sufficiently varied to result inany appreciable differences in plant growth. Consequently, such ratios must be interpreted in only a general sense. Ulrich (1952), in discussing the nutrient balance concepts of Shear gt a_1 (1946, 1 948), has pointed to the impossibility of maintaining a single nutrient at a specified concentration within a plant. It would 3 eem more expedient to study the effect of nutrient relationships .a I ".1:- on growth until such time as the specific role of each nutrient in plant metabolism has been sufficiently elucidated. Bear (1950), Van Itallie (1938), and Bear and Prince (1945) have pointed to the presence of a rather constant total cation content in plants, together with a similar constant cationzanion ratio. However, they hasten to explain that these constant ratios are only found under conditions of balanced or normal soil fertil- ity, Data presented in this thesis would support. this general conclusion insofar as seeds are concerned, even with severely un- balanced soil fertility. However, if composition of the entire plant is considered, the cation content was not a constant. As Ph°39hate was the only anion determined, it is difficult to draw any cOnclusions on the constancy of the cation:anion ratio. Based °“ the data available, it would appear that the cation:anion ratio did not, approach a constant value._ under the conditions of this ”periment. An excess absorption of cations compared to anions is over— come by the production of organic acids, particularly malate \bkC0bson and Ordin, 1954; Hoagland and Broyer, 1940). Thus the ”action of the cellular contents remains essentially the same. sifljlarly, an excess of anions absorbed is compensated by a pro— por-tional reduction in the organic acid content. Where the ac- tivities of cations and anions are similar, almost equal quantities of each will be absorbed from a given system. However, if the activity of the anion exceeds that of’lthe cation, additional quantities of anion will be absorbed with a proportionate decline 94 in malic acid concentration, presumably to serve as metabolite in the tricarboxylic acid cycle (Lundegardh, 1955). Unfortunately, no evidence is available in the present study to confirm or refute this conclusion. Presumably potassium chloride would result in an increased uptake of both ions due to similar activities. Calcium and magnesium carbonates, because of the low activity of the bicarbonate ion, would result in an excess of these cations in the cells, with a subsequent increase in the organic acid content of the tissue. In a polyionic environment, such as that experienced under field conditions, variations in organic acid content are doubtless much less than those found in homionic systems in the laboratory. The extent to which the chemical composition of a plant is. an index of the nutritive value of that plant is questionable. Certainly the content of phosphorus, calcium, magnesium and man- ganese can be of value in interpreting composition in terms of nutritive value. Nitrogen may or may not be included, as the quality of the nitrogen in terms of amino acids is often of greater significance than the total nitrogen content (Morrison, 1947) - With the possible exception of phosphorus, it may be c”cluded that the nutritive value of seeds as measured by chemical conlpcl'Sition is not materially affected by unbalanced soil fertility levels . However, vegetative plant parts are subject to wider variations so that unbalanced soil fertility canditions can alter the plant as far as feedingyalae is concerned. The extent of this effect canionly be ascertained accurately by biological assay. 95 It; Feeding trials with rats were conducted to determine the effect of soil treatment on the nutritional value of corn and soy- beans.1 No differences in animal growth were observed, but vari- ations in the Ca:P ratio of bones could be related to differences in the Ca:P ratio of the feed. However, no feeding trials were conducted to determine the effect of changing the composition of timothy and soybean hay on the nutritive value of these crops. 1Rutherford, B. Elaine, and Pretty, K. M. 1958. Unpub- lished data. 96 SUMMARY AN D CONCLUSIONS Field and laboratory studies were conducted in 1955 and 1956 to determine the effect of unbalanced soil fertility on the growth and nutritive value of several crops, as assessed by yields and chemical composition. Relatively large amounts of calcitic and dolomitic limestone, phosphorus and potassium were applied in all combinations to an extremely infertile Kalamazoo sandy loam soil . Vegetative portions of timothy and soybeans, and the mature seed of millet, soybeans, corn and wheat were harvested for yield data and the determination of chemical composition. The results obtained from these investigations may be sum- marized as follows: 1. Crop yields were increased by some soil treatments de- Pending on the plant species. Calcitic limestone increased the yields of timothy hay and wheat in 1956 while dolomitic limestone increased corn and wheat yields. Phosphorus applications increased 5°Ybean hay and millet yields in 1955 and wheat yields in 1956. P°tassium depressed the yield of soybeans in 1956 and increased the Yield of millet and corn in 1956. 2. It is concluded that crop yields on this soil cannot be incr"Nised to normal values within a two-year period, even with balaDCed nutrient applications. The calcium, magnesium and potas- sium cOntents of timothy and soybean hay were generally increased by the application of these nutrients to the soil. However, seed 97 crops increased only in magnesium as a result of the same soil treatments. 3. Phosphorus applications to the soil substantially and consistently increased the phosphorus content of all crops grown. 4. Lime applications greatly decreased the exchangeable manganese content of the soil and the total manganese in plant tissue. However, the manganese content of the crops was not directly related to the exchangeable manganese levels in the soil. 5. There was a distinct tendency for phosphorus and potas— sium to increase the manganese content of plants although con- siderable variation occurred between 1955 and 1956. 6. Lime applications had no appreciable effect on phos- phorus accumulation by plants. Calcitic limestone did not affect the potassium content of crops but dolomitic lime reduced the pOtassium content of wheat, corn, soybean hay and soybean seed. 7. The application of phosphorus increased the total cation content of corn, and the 1956 millet crop, as well as the crude ash content of timothy hay, millet, corn and wheat. Phos- Ph°PUS also increased the magnesium content of millet, corn and timothy hay. 8. Magnesium contents were generally decreased by potassium fertilization, especially in wheat, soybean hay and the 1956 ti'othy hay crop. Calcium levels were depressed in 1956 by po- tassium applications to timothy and soybean hay. 9. The Mg/K ratio was the most important factor determining the total cation content of crops. An increase in the content of 98 one did not result in an equivalent decrease in the other, so that the total cation content increased or decreased depending on the proportionate uptake of each ion. There was no tendency toward a constant cation content except in soybean grain. 10. Sodium, nitrogen and crude ash levels in the plant were not consistently affected by any soil treatment. However, there was a tendency for lime applications to increase the nitrogen con— tent of the crops and for phosphorus and potassium to increase the crude ash. 11. The total cation content of the plants was not closely related to soil pH or percent base saturation, but was primarily affected by Mg/K relationships. 12. A comparison between crop yields and plant composition failed to show a definite relationship between the two. 13. It is concluded that plant composition, although closely rel. ated to the availability or percent saturation of the soil col- 1°id by any particular ion, is also affected by the cation exchange cali'acity of the roots, the balance between nutrients'and the com- PEtition between ions for sites on the absorption or ion-carrier mechanism. I 14. Due to the exclusion of certain ions by an as yet un- known mechanism, the cation composition of reproductive parts of plants was not appreciably changed by unbalanced soil fertility conditions. The composition of vegetative plants can be sub- stantially altered by similar conditions. 99 , i“ 15. The extent to which soil treatment altered the nutritive value of the crops studied through a change in undetermined consti- tuents is a question of great magnitude. The importance of the variations in plant composition herein reported in the nutrition of axiimmls and man is also open to debate. 100 ‘;13r LITERATURE CITED Albaum, H. G. 1952. The role of phosphorus in the metabolism of plants. The Biology of Phosphorus. Mich. State College Press, East Lansing, 147 pp. Anderson, A. K. 1947. Essentials of Physiological Chemistry. John Wiley and Sons, Inc., New York, 395 pp. Artiomi, D. I., and D. R. Hoagland. 1943. Composition of the tomato plant as influenced by nutrient supply in relation to fruiting. Bot. Gaz. 104:576-590. Association of Official Agricultural Chemists. 1945. Official and Tentative Methods of Analysis. 6th Edition. Washington, D. C. Beax:t1er, R. L., D. Longnecker, and F. G. Merkle. 1952. Influence of form, fineness, and amount of limestone on plant develop- ment and certain soil characteristics. Soil Sci. 73:75-82. Beale, F. E. 1950. Cation and anion relationships in plants and their bearing on crop quality. Agron. Jour. 42:176-178. Bea1~, F. E., and A. L. Prince. 1945. Cation equivalent constancy in alfalfa. Agron. Jour. 37:217-222. Beaumont, A. B., and M. E. Snell. 1935. The effect of magnesium deficiency on crop plants. Jour. Agr. Res. 50:553-562. Beeson , K. C. 1941. The mineral composition of crops with particu- lar reference to soils in which they are grown. U.S.D.A. Misc. Publ. 369, 164 pp. __________3 1946. The effect of mineral supply on the mineral con- centration and nutritional quality of plants. Bot. Rev. 12:424-455. —_________. 1947. Better soils, better food. Science in Farming. IJ,S.D.A. Yearbook of Agriculture, 944 pp. , C. B. Lyon, and M. W. Barrantine. 1944. Ionic absorption 13y tomato plants as correlated with variations in the compo- sition of the nutrient medium. Plant Physiol. 19:258-277. Bend"r‘~ I. H., and I. S. Eisenmenger. 1941. Intake of certain elements by calciphilic and calciphobic plants grown on soils differing in pH. Soil Sci. 52:297-307. Blair, A. W., and A. L. Prince. 1939. Studies on the nitrogen, phosphorus and mineral requirements of alfalfa. Soil Sci. 47:459-466. Boyoucous, G. J. 1936. Directions of making mechanical analyses of soils by the hydometer method. Soil Sci. 42:225-229. Bray, R. H., and L. T. Kurtz. 1945. Determination of total, organic, and available forms of phosphorus in soils. Soil Sci. 59:39-45. Broyer, T. C. 1951. The nature of the process of inorganic solute accumulation. Mineral Nutrition of Plants. E. Truog, editor. University of Wise. Press. Madison, 469 pp. Car1>1|Js, R. L. 1933. Some factors affecting the absorption of magnesium in the potato plant. Proc. Amer. Soc. Hort. Sci. 30:480-484. . 1935. Effects of magnesium deficiency in the soil on the yield, appearance, and composition of vegetable crops. Proc. Amer. Soc. Hort. Sci. 31:610-614. . 1938. Effect of certain ions, used singly and in com- bination. on the growth, and potassium, calcium and magnesium absorption of the bean plant. Plant Physiol. 13:349-363. Cartter, J. L., and T. H. Hopper. 1942. Influence of variety, environment, and fertility level on the chemical composition of the soybean seed. U.S.D.A. Tech. Bull. 787, 66 pp. Cederquist, Dena C., and Margaret A. Ohlson. 1955. Nutritive value of milk produced by cows fed rations from low and high fertility soils. Nutrition of Plants, Animals, Man. Mich. State Univ. Coll. Agr. Cent. Symp., East Lansing, 111 pp. Chu-hers, w. E., and H. w. Gardner. 1951. The effect of soil calcium on the mineral content of wheat. Jour. Soil Sci. 2:246-2530 Ch", T. 8., and L. M. Turk. 1949. Growth and nutrition of plants as affected by degree of base saturation of different types of clay minerals. Mich. Agr. Exp. Sta. Tech. Bull. 214, ‘47 pp. Chne s R. A. 1957. The effect of applied fertilizer and oxygen diffusion rate on the growth, yield and chemical composition of peas. Unpublished M. S. thesis, Mich. State Univ., 76 numb. leaves. Collander, R. 1941. Selective absorption of cations by higher plants. Plant Physiol. 16:691-720. Cook, R. L., and C. E. Millar. 1953. Plant nutrient deficiencies. Mich. Agr. Exp. Sta. Spec. Bull. 353 (revised), 82 pp. Coopeq‘,lL P., W. Paden, and W. Garman. 1947. Some factors in- fluencing the availability of magnesium in soil and the magnesium content of certain crop plants. Soil Sci. 63: 27-40 I Danijel, H. A., and H. J. Harper. 1934. The relation between total calcium and phosphorus in mature prairie grass and available plant food in the soil. Jour. Amer. Soc. Agron. 26:986-992. Dexter, S. T., C, W. Duncan, Dena C. Cederquist, K. M. Dunn, C. E. Millar. L. M. Turk E. Weaver, and R. Prior. 1950. Nutritive value of crops and cow's milk as affected by soil fertility. I. The research problem and procedures. Mich. Agr. Exp. Sta. Quar. Bull. 32:352-359. Drake, M., J. Vengris, and W. 7G. Colby. 1951. Cation exchange capacity of roots. Soil Sci. 72:139-147. Drosscic>ff, M., and D. C. Nearpass. 1948. Quantitative microdeter- mination of magnesium in plant tissue and soil extracts. Anal. Chem. 20:673-674. Duncan, C. W. 1955a. Effects of fertilizer practices on plant composition. 1. Field results. Nutrition of Plants, Animals, Man. Mich. State Univ. Coll. Agr. Cent. Symp., East Lansing, 111 pp. __________. 1955b. Effects of fertilizer practices on the nutritive value of feed for four successive generations of dairy cows. 11. Composition of milk produced from feeds grown on fer- tilized, unfertilized soil. Nutrition of'Plants, Animals, Man. Mich. State Univ. Coll. Agr. Cent. Symp., East Lansing, 111 pp. , G. 1. Watson, K. M. Dunn, and R. E. Ely. 1952. Nutritive 'Value of crops and cow's milk as affected by soil fertility. II. The essential amino acids in colostrum and milk protein. «Jour. Dairy Sci. 35:128-139. Elgabaly, M. M., and L. Wiklander. 1949. Effect of exchange (:apacity of clay mineral and acidoid content of plant on laptake of sodium and calcium by excised barley and pea I‘oots. Soil Sci. 67:419-424. «00o... ) Epstein, E., and c. E. Hagen. 1952. A kinetic study of the ab- sorption of alkali cations by barley roots. Plant Physiol. 27:457-474. Epstein, E. and P. R. Stout. 1951. The micronutrient cations, iron, zinc and copper: their uptake by plants from the absorbed state. Soi1.Sci. 72;47-65. Freeland, R. 0. 1936. Effect of transpiration upon the absorption and distribution of minerals salts in plants. Amer. Jour. Bot. 23:335-362. . 1937. Effect of transpiration upon the absorption of mineral salts. Amer. Jour. Bot. 24:373-374. Fujimoto, C. K. and G. D. Sherman. 1948. Behavior of manganese in the soil and the manganese cycle. Soil Sci. 66:131-145. Gauch, H. G. 1957. Mineral nutrition of plants. Ann. Rev. Plant Physiol. 8:31-64. Graham, E, R., and W. A. Albrecht. 1952. Potassium bearing minerals as soil treatments. Univ. Mo. Res. Bull. 510:1-12. Graham, E. R. and W. L. Baker. 1951. Ionic saturation of plant roots with special reference to hydrogen. Soil Sci. 72: 435-441. Hoagland. D. R. and T. C. Broyer. 1936. General nature of the process of salt accumulation by roots with description of experimental methods. Plant Physiol. 11:471-507. . 1940. Hydrogen-ion effects and the accumulation of salt by barley roots as influenced by metabolism. Amer. Jour. Bot. 27:173-185. Hoff, D. J. and H, J. Mederski. 1958. The chemical estimation of plant available soil manganese. Soil Sci. Soc. Amer. Proc. 22:129-132. Jacobson, L. and L. Ordin. 1954. Organic acid metabolism and ion absorption in roots. Plant Physiol. 29:70—75. elacobson, L., R. Overstreet, H. M. King, and R. Handley. 1950. A study of potassium absorption by barley roots. Plant Physiol. 25:639-647. lyawton, K. 1945. The influence of soil aeration on the growth and absorption of nutrients by corn plants. Soil Sci. Soc. Amer. Proc. 103263-268. 104 'Lawton, K. and R. L. Cook. 1954. Potassium in plant nutrition. Adv. in Agron. VI:253-303. Lawton, K., T. M. Lai, and G. A. Wieczorek. 1958. A comparison of the availability to plants of phosphorus from mixed salt and commercial type mixed fertilizers. Jour. of Agr. and Food Chem. (in press). Lawton, K., C. Apostolakis, R. L. Cook, and W. L. Hill. 1956. Influence of particle size, water solubility, and placement of fertilizers on the nutrient value of phosphorus in mixed fertilizers. Soil Sci. 82:465-476. Loehwing, W. F. 1951. Mineral nutrition in relation to ontogeny K of plants. Mineral Nutrition of Plants. E. Truog, editor. Univ. of Wisc. Press, Madison, 469 pp. Lucas, R. E. and G. D. Scarseth. 1947. Potassium, calcium, and magnesium balances and reciprocal relationships in plants. Jour. Amer. Soc. Agron. 39:887-896. Lundegardh, H. 1955. Mechanisms of absorption, transport, accumu- lation and secretion of ions. Ann. Rev. Plant Physiol. 6:1—24. Lyon, C. B. and K. C. Beeson. 1948. Influence of toxic concen- trations of micro-nutrient elements in the nutrient medium on the vitamin content of turnips and tomatoes. Bot. Gaz. 109:506-520. 5 MacLean, A. J. 1956. Influence of additions of lime to soils on , the availability of potassium and other cations for alfalfa. Can. Jour. Agr. Sci. 36:213-220. Macy, P. 1936. The quantitative mineral nutrient requirements of plants. Plant. Physiol. 11:749—764. Marshall, C. E. 1948. Ionization of calcium from soil colloids and its bearing on soil—plant relationships. Soil Sci. 65:57-68. . 1951. The activities of cations held by soil colloids and the chemical environment of plant roots. Mineral Nutri- tion of Plants. E. Truog, editor. Univ. of Wise. Press, Madison, 469 pp. and S. A. Barber. 1950. The calcium-potassium relation- ships of clay minerals as revealed by activity measurements. Soil Sci. Soc. Amer. Proc. 14:86-88. ‘ A__.. .3,.—:~ , ‘“httson, S. 1948. Laws of ionic exchange. III. Ann. Agr. Coll. Sweden 15:308-316. The effect of potassium McCalla, A. G., and E. K. Woodford. 1935. II. Can. supply on the composition and quality of wheat. Jour. Res. 13:339-354. . 1938. Effects of a limiting element on the absorption of individual elements and on the anion:cation balance in wheat. Plant Physiol. 13:695-712. Further studies involving McLean, E. 0.. and D. Adams. 1954. Soil Sci. cationic activities in systems of plant roots. Soc. Amer. Proc. 18:273-275. McLean, E. 0. and F. E. Baker. 1953. Cationic activities in systems of plant roots. Soil Sci. Soc. Amer. Proc. 17:100-102. Effect of magnesium on growth and McMurtrey, J. E. Jr. 1947. Soil Sci. 63:59-67. composition of tobacco. Mehlich, A. 1946. Soil properties affecting the proportionate amounts of calcium, magnesium, and potassium in plants and HCl extracts. Soil Sci. 62:393-410. and N. T. Coleman. 1952. Type of soil colloid and the mineral nutrition of plants. Adv. in Agron. 4:67-99. Mehlich, A. and W. E. Colwell. 1943. Influence of nature of soil colloids and degree of base saturation on growth and nu— trient uptake by cotton and soybeans. Soil Sci. Soc. Amer. Proc. 8:179-184. . 1946. Absorption of calcium by peanuts from kaolin and bentonite at varying levels of calcium. Soil Sci. 61:369-374. Mehlich, A. and M. Drake. 1955. Soil chemistry and plant nutri- tion. Chemistry of the Soil, F. E. Bear, editor. Reinhold Publ. Corp. New York, 373 pp. Mehlich, A. and J. F. Reed. 1948. Effect of cation-exchange properties of soil upon the cation content of plants. Sci. 66:289-306. Soil Morrison, F. B. 1947. Feeds and Feeding. 20th edition. Morrison Publ. Co., Ithaca, N. Y., 1050 pp. Naftel, J. A. 1937. Soil-liming investigations. IV. The influence of line on yields and on the chemical composition of plants. Jour. Amer. Soc. Agron. 29:537-547. “e‘ton. J. D. 1923. A composition of the absorption of inorganic elements, and of the buffer systems of legumes and non- legumes. and its bearing upon existing theories. Soil Sci. 15:181-204. Norman, A. G. 1955. Influence of environmental factors on plant composition. Nutrition of Plants, Animals, Man. Mich. State Univ. Coll. Agr. Cent. Symp., East Lansing, 111 pp. Overstreet, R. and L. Jacobson. 1952. Mechanisms of ion absorp- tion by roots. Ann. Rev. of Plant Physiol. 3:189-206. Overstreet, R., L. Jacobson, and R. Handley. 1952. The effect of calcium on the absorption of potassium by barley roots. Plant Physiol. 27:575-582. Page, J. B. and G. B. Bodman. 1951. The effect of soil physical properties on nutrient availability. Mineral Nutrition of Plants. E. Truog, editor. Univ. of Wise. Press, Madison, 469 pp. Peech, M. 1945. Determination of exchangeable cations and exchange capacity of soils -- rapid micromethods utilizing centrifuge and spectrophotometer. Soil Sci. 59:29-37. Peterson, W. J. and H. F. Krachenberger. 1954. Effect of environ- ment on the calcium content of plants. Influence of Environ- ment on the Chemical Composition of Plants. Southern Coop. Series Bull. 36: 198 pp. Power, J. F. 1954. Effects of lime and fertilizer upon plant growth and composition. Unpublished Ph. D. thesis, Michigan State College, 193 numb. leaves. Power, J. F., R. M. Swenson and R. L. Cook. 1955. Effects of fertilizer practices on plant composition. Greenhouse re- sults. Nutrition of Plants, Animals, Man. Mich. State Univ. Coll. Agr. Cent. Symp., East Lansing, 111 pp. Prince, A. L., M. Zimmerman, and F. E. Bear. 1947. The magnesium supplying power of 20 New Jersey soils. Soil Sci. 63:69-78. Richards, L. A. and C. H. Wadleigh. 1952. Soil water and plant growth. Soil Physical Conditions and Plant Growth. B. T. Shaw, editor. Academic Press, Inc., New York, 491 pp. Russell, M. B. 1952. Soil aeration and plant growth. Soil Physical Conditions and Plant Growth. B. T. Shaw, editor. Academic Press, Inc., New York, 491 pp. Sayre, cl. P. 1948. Mineral accumulation in corn. Plant Physiol. 23:267-281. Shaw, B. T. 1952. Soil Physical Conditions and Plant Growth. Academic Press, Inc., New York, 491 pp. Shear, C. 8., H1 Ll Crane, and A. T. Meyers. 1946. Nutrient—element balance. A fundamental concept in plant nutrition. Proc. Amer. Soc. Hort. Sci. 47:239-248. 1948. Nutrient-element balance : Application of the concept to the interpretation of foliar analysis. Proc. Amer. Soc. Hort. Sci. 51:319-326. Stanford, G., S. B. Kelly, and W. H. Pierre. 1942. Cation balance in corn grown on high—lime soils in relation to potassium deficiency. Soil Sci. Soc. Amer. Proc. 6:335-341. Steckel, J. E., B. R. Bertramson and A. J. Ohlrogge. 1949. Manganese nutrition of plants as related to superphosphate. Soil Sci. Soc. Amer. Proc. 13:108-111. Steward, E. H. and N. J. Volk. 1946. Relation between potash in soils and that extracted by plants. Soil Sci. 61:125—129. Stout, P. R. and R. Overstreet. 1950. Soil chemistry in relation to inorganic nutrition of plants. Ann. Rev. Plant Physiol. 1:305-342. Stubblefield, F. M. and E. E. DeTurk. 1940. The composition of corn, oats, and wheat influenced by soil, soil treatment, seasonal conditions, and growth. Soil Sci. Soc. Amer. Proc. 5:120-124. Taylor. G. A. 1954. The effects of three levels of magnesium on the nutrient-element composition of two inbred lines of corn and on their susceptibility to Helminthosporium maydis. Plant Physiol. 29:87-91. Truog, E. 1951. Mineral Nutrition of Plants. Univ. of Wisc. Press, Madison, 469 pp, , R. J. Goates, G. C. Gerloff, and K. C. Berger. 1947. Magnesium—phosphorus relationships in plant nutrition. Soil Sci. 63:19-25. Tyson, J. 1930. Influence of soil conditions, fertilizer treat- ments, and light intensity on growth, chemical composition, and enzymatic activities of sugar beets. Mich. Agr. Exp. Sta. Tech. Bull. 108, 44 pp. “lri4fi\, A. 1946. Critical phosphorus and potassium levels in Ladino clover. Soil Sci. Soc. Amer. Proc. 10:150-161. . 1952. Physiological bases for assessing the nutritional requirements of plants. Ann. Rev. of Plant Physiol. 3:207- 228. Underwood, E. J. 1956. Trace Elements in Human and Animal Nutri- tion. Academic Press, Inc., New York, 430 pp. Van Itallie, Th. B. 1938. Cation equilibria in plants in relation to the soil. Soil Sci. 46:175-186. Vlamis, J. 1949. Growth of lettuce and barley as influenced by degree of calcium saturation of soil. Soil Sci. 67:453-466. Wallace, A., S. J. Toth and F. E. Bear. 1948. Influence of sodium on growth and composition of Ranger alfalfa. Soil Sci. 65:249-258. Ward, G. M., E. Weaver, R. E. Ely and K. M. Dunn. 1955. Effect of fertilizer practices on nutritive value of feed for four successive generations of dairy cows. Nutrition of Plants, Animals, Man. Mich. State Univ. Coll. Agr. Cent. Symp., East Lansing, 111 pp. Wedin, W. F., A. W. Burger, and H: L. Ahlgren. 1956. Effect of soil type, fertilization, and stage of growth on yield, chemical composition, and biological value of ladino clover. (Trifolium repens, L.) and alfalfa (Medicago sativa). Agron. 6 Jour. 48:147-152. ~ Willard, D. G. and L. H. Greathouse. 1917. The colorimetric deter- ‘ mination of manganese by oxidation with periodate. Jour. Amer. Chem. Soc. 39:2366-2377. Williams, B. C. 1955. Granulated versus nongranulated fertilizers; effect upon yield and uptake of phosphorus by several crops. Unpublished Ph. D. thesis, Michigan State College, 108 numb. leaves. Williams, D. E. and N. T. Coleman. 1950. CationLexchange proper- ties of plant root surfaces. Plant and Soil 2:243-256. Windham, S. 1953. The influence of various levels of calcium, potassium, and magnesium in the soil on the absorption and yield response to potassium and magnesium by seventeen vegetable crops. Unpublished Ph. D. thesis, Michigan State College, 98 numb. leaves. “ithrow, R. B. 1951. Light as a modifying influence on the mineral nutrition of plants. Mineral Nutrition of Plants. E. Truog, editor. Univ. of Wise. Press, Madison, 469 pp. 3' . .‘ . " (r ’ ‘ ~ . ~ 2 «I W :- ..s APPENDIX .1...“ TABLE XIX THE EFTECT OF FERTILIZER AND LIME TREATMENTS AND CROP GROWN ON THE SOIL NUTRIENT CONTENT Treatment Ca Mg K Na 2 Exch. Mn pH (percent saturation) (lbs/A) (ppm) Timothy hay - 1955 None 26.7 3.7 1.8 1.3 22 66 5.4 p 23.4 3.7 1.9 1.7 191 71 5.2 x 25.7 3.1 5.4 1.3 22 71 5.3 PK 26.9 3.8 5.7 1.3 210 74 5.2 L18 40.6 9.4 1.6 1.2 18 64 5.6 L1P 44.6 7.3 1.5 1.5 170 63 5.7 le 38.9 8.3 5.6 1.3 27 64 5.5 Llpx 42.0 9.7 5.1 1.5 189 64 5.6 Lab 25.7 5.9 1.6 1.6 28 53 5.4 L2? 34.5 5.6 1.4 1.5 193 58 5.4 L2K 19.7 5.6 5.5 1.1 22 55 5.3 L2PK 27.8 5.7 5.1 1.1 .153 61 5.4 Soybean hay - 1955 None 30.2 4.2 1.8 1.1 25 53 5.2 p 28.7 3.3 1.6 1.0 133 52. 5.1 x 22.9 3.8 4.5 1.3 33 81 4.9 PK 26.3 3.1 3.7 1.4 160 79 5.0 L18 48.7 14.1 1.8 1.2 28 39 5.9 L1? 58.8 12.7 2.2 1.6 153 51 5.7 le 43.5 10.1 4.0 - 1.7 24 51 5.7 Llpx 43.1 10.8 3.8 1.7 155 55 5.6 L2b 34.2 11.1 1.7 1.1 17 48 5.6 L2? 35.6 10.4 2.0 1.3 148 51 5.5 sz 27.5 10.4 3.4 1.1 19 44 5.6 szx 35.4‘.10.3 3.0 1.7 133 47 5.5 aCa1c1t1c lime bDolomitic lime a ..... TABLE XIX (Cont.) Treatment C?perce:% satufation)Na (lbsgA) Ex::§.Tn Timothy hay - 1956 None 28.2 7.5 1.9 0.6 23 41 5.2 p 33.7 7.7 2.1 0.6 187 39 5.1 K 22.6 7.5 6.9 0.8 40 47 5.2 PK 27.1 5.7 6.4 0.8 224 50 5.0 L18 85.9 7.7 1.6 0.7 27 29 6.0 LIP 67.1 7.5 1.4 0.6 178 26 6.0 le 68.9 9.6 6.2 0.8 24 30 6.0 Llpx 81.7 7.0 6.5 0.9 214 36 6.1 L2b 49.7 43,7 1.9 0.8 20 23 6.1 L2? 50.8 30.4 1.5 0.7 290 24 6.0 L2K 49.4 44.0 4.8 0.7 28 22 6.0 szx 48.0 36.9 5.7 0.7 214 27 6.0 Soybean hay - 1956 None 32.0 3.3 1.9 0.6 33 30 5.0 p 31.3 3.3 1.5 0.6 135 26 4.9 K 25.4 2.8 3.6 0.7 38 38 4.9. PK 27.1 _4.0 4.6 0.7 158 35 5.0 L18 61.9 9.9 1.4 0.9 36 10 6.4 LIP 73.7 11.5 1.7 1.0 145 11 6.3 le 61.2 10.3 3.8 0.9 31 10 6.2 Llpx 79.3 11.0 3.4 1.0 130 8 6.5 L2b 52.9 40.9 1.8 0.7. 37 6 6.4 L2P 59.5 38.8 1.8 0.7 143 8 6.2 Lax 44.5 29.9 4.0 0.6 32 9 6.1 szx 50.8 32.2 4.0 0.7 143 6 6.3 TABLE xxx (Cont.) Treatment Ca Mg Na P Exch. Mn pH (percent saturation) (lbs/A) (ppm) Millet grain - 1955 None 33.3 3.8 1.8 1.1 25 65 5.3 P 35.9 4.3 2.0 0.9 143 71 5.2 X 26.1 3.5 3.7 1.3 37 74 5.2 PK 28.7 3.3 3.4 1.0 152 71 5.2 L1 45.2 11.5 1.7 0.9 35 49 5.7 LIP 44.9 11.8 1.6 1.2 163 36 5.7 L1K 48.9 11.8 3.7 1.1 27 40 5.8 L1PK 56.8 13.7 3.5 1.2 168 44 5.8 L2 37.1 14.4 1.6 1.0 40 49 5.6 L2? 38.3 11.5 1.3 0.8 164 49 5.7 L2K 32.5 11.1 3.0 1.0 28 40 5.8 LZPK 32.7 11.3 3.5 1.1 158 46 5.6 Soybean grain - 1955 None 22.0 3.1 2.1 0.9 28 67 5.2 P 29.2 3.1 2.3 1.1 148 68 5.3 R 23.2 2.6 4.0 1.3 27 72 5.0 PK 26.7 2.8 4.2 0.7 158 70 5.2 L1 37.9 9.7 1.8 1.2 24 43 5.5 L}? 48.7 13.4 1.7 1.3 155 44 6.0 le 37.3 13.6 4.4 0.9 29 ‘46 5.9 LIPK 51.6 13.4 5.0 1.2 192 41 5.9 L2 34.5 12.7 1.9 1.1 27 47 5.7 L2P 34.2 10.4 1.8 1.1 145 50 5.7 L2K 29.2 14.4 3.4 1.1 29 52 5.7 LZPK 27.8 10.4 4.5 0.7 158 49 5.7 .——--—-———--_———————_————————-———-——— TABLE XIX (Cont.) Treatment Ca Mg K Na P Exch. Mn pH (percent saturation) (lbs/A) (ppm) Millet grain - 1956 None 29.6 3.8 1.8 0.7 33 28 5.0 P 35.1 4.2 1.8 0.7 124 29 5.0 K 28.2 3.8 4.9 0.7 46 44 5.0 PK 32.7 4.7 5.5 0.9 168 45 4.9 L1 74.4 16.0 2.4 1.0 35 11 6.1 1 LIP 80.7 16.2 2.5 1.1 145 10 6.5 3 LlK 77.2 9.9 4.2 0.9 40 7 6.5 LIPK 85.6 13.6 4.4 1.0 150 9 6.5 L2 50.8 38.4 1.8 0.7 28 6.4 L2P 59.5 45.9 1.9 1.1 173 8 6.2 L2K 45.6 34.3 3.6 0.8 33 10 6.2 L2PK 53.6 44.7 3.4 0.7 169 9 6.5 Soybean grain — 1956 None 35.5 5.9 2.1 0.9 32 23 5.2 P 37.2 3.8 2.1 0.8 130 27 5.1 K 25.0 3.5 4.0 0.7 46 29 5.0 PK 32.7 4.5 4.1 0.9 ~l63 30 5.1 L1 82.8 10.4 1.9 1.0 42 6 6.4 LIP 75.8 7.3 1.7 1.1 155 8 6.5 LIX 80.7 11.5 3.9 0.9 31 7 6.6 LIPK 74.4 11.7 4.4 1.0 160 7 6.6 L2 52.2 33.6 1.7 1.0 32 5 6.6 L2P 51.8 25.7 1.7 1.0 184 5 6.5 L2K 49.4 34.3 3.9 1.4 39 8 6.5 L2PK 51.5 38.4 3.7 1.0 145 8 6.5 MI 4' lnd!’ . lu‘b‘u .‘uundlhmdnlh4lpIIVr \ 115 TABLE x1x (Cont.) Treatment on Mg K Na P Exch. Mn pH (percent saturation) (lbs/A) (ppm) Corn grain — 1955 None 23.2 3.1 2.1 1.1 24 55 5.1 P 26.7 2.3 1.7 1.2 100 46 5.0 K 22.9 2.1 5.7 1.5 29 75 5.0 PK 28.1 2.3 5.0 1.4 142 59 5.1 L1 40.0 13.7 1.7 1.2 24 29 5.6 LIP 49.6 14.8 2.1 1.3 145 29 5.7 le 45.8 12.9 4.1 1.4 21 25 5.5 LIPK 50.4 12.7 4.2 1.3 103 31 5.8 L2 39.7 15.7 2.6 1.7 27 35 5.3 L2P 37.4 15.7 2.5 1.5 136 37 5.4 L2K‘ 28.4 11.8 4.7 1.5 30 32 5.4 L2PK 32.5 12.9 3.9 1.2 129 31 5.4 Fallow - 1955 None 29.0 4.5 2.6 1.0 32 75 5.3 P 33.0 3.7 2.3 1.9 148 78 5.2 K 23.2 3.7 3.3 1.7 35 76 5.2 P! 29.0 4.3 4.2 1.3 152 84 5.2 L1 42.0 10.8 2.3 1.5 38 58 5.7 LIP 52.2 11.8 2.1 1.4 148 46 5.9 LIX 39.1 10.4 3.3 1.5 28 49 5.9 LIPK 38.3 ‘9.7 3.1 1.4 125 52 5.8 L2 35.9 13.9 2.2 1.1 27 52 5.7 L2P 31.3 10.8 2.0 2.0 128 58 5.6 L2K 27.8 10.3 3.3 3.3 39 54 5.7 LZPK 32.1 10.3 3.5 3.5 138 59 5.6 TABLE xxx (Cont .) Treatment Ca Mg K . Na P Exch. Mn pH (percent saturation) (lbs/A) (ppm) Corn grain - 1956 None 31.3 5.7 1.5 0.9 40 13 P 30.6 5.6 1.6 1.1 143 14 . K 26.4 4.9 3.7 1.1 44 18 . PK 28.7 4.5 3.8 1.1 168 19 L1 80.5 17.4 1.2 1.0 35 6 . LIP 75.8 16.5 1.7 1.0 155 4 . L1K 78.3 20.5 3.4 1.0 32 6 . LIPK 79.1 17.9 5.0 1.0 143 6 . L2 51.3 47.8 1.7 1.2 32 5 L2P 54.2 43.5 1.6 1.0 153 5 L2K 48.8 45.6 3.7 1.3 30 5 L2PK 50.9 45.7 3.7 0.9 117 5 . Wheat grain - 1956 None 30.6 6.3 2.4 0.9 29 46 5.0 P 34.1 7.0 1.9 0.9 120 39 5.1 K 21.6 3.1 2.7 1.0 36 37 5.0 PK 27.1 3.7 3.9 1.0 150 43 5.0 L1 50.1 16.2 2.0 1.0 29 14 5.6 LIP 55.0 16.5 1.7 0.8 125 13 6.0 LlK 49.4 16.5 3.1 1.1 31 14 5.9 LlPK 45.2 11.7 2.9 1.0 106 15 5.7 L2 41.0 18.3 1.7 0.7 33 19 5.7 L2P 39.7 17.2 1.4 0.8 160 15 5.7 L2K 36.9 21.2 2.4 0.6 33 13 6.0 L2PK 36.9 23.1 2.6 0.7 130 9 5.8 THE EFFECT OF SOIL TREATMENT ON THE CHEMICAL COMPOSITION OF CROPS STUDIED TABLE XX Treatment Ca Mg K Na Total P Mn N Ash (m.e./100 grams) (percent) Timothy hay - 1955 None 3.1 . 26.8 0.40 32.9 0.13 0.020 0.90 3.94 P 3.1 30.7 0.38 38.4 0.19 0.018 0.92 4.47 K 3.3 34.1 0.39 42.2 0.13 0.021 0.92 4.48 PK 3.0 . 38.9 0.43 46.2 0.24 0.022 1.00 5.56 L18 3.5 . 27.4 0.33 35.6 0.14 0.014 0.97 4.16 LIP 3.1 . 28.8 0.24 36.5 0.24 0.018 0.96 4.78 LlK 3.9 . 36.2 0.41 44.8 0.15 0.018 0.97 4.84 LIPK 3.7 . 40.0 0.23 48.1 0.23 0.019 1.06 5.55 Lab 3.5 . 29.2 0.19 37.0 0.12 0.160 0.91 3.98 L2P 3.2 25.7 0.21 35.0 0.23 0.170 0.94 4.65 L2K 4.0 . 34.1 0.22 41.8 0.13 0.210 1.01 4.51 L2PK 3.1 . 38.9 0.20 46.8 0.25 0.230 0.98 5.52 Soybean hay - 1955 None 59.4 34.2 23.5 0.14 117.2 0.15 0.036 2.30 5.76 P 50.6 35.5 22.4 0.09 108.6 0.25 0.082 2.84 5.59 K 45.0 32.4 40.6 0.13 118.1 0.21 0.098 2.75 6.65 PK 58.8 30.8 39.1 0.11 128.8 0.26 0.091 2.83 6.75 L1a ‘ 63.8 38.0 27.1 0.12 129.0 0.21 0.035 3.02 6.37 LIP 56.3 42.1 23.4 0.13 121.9 0.30 0.073 3.08 5.86 LlK 70.6 36.0 33.5 0.12 140.1 0.17 0.051 2.80 6.76 LIPK 57.5 32.7 33.7 0.13 124.0 0.25. 0.035 2.77 6.37 Lab 63.8 38.0 24.9 0.13 126.7 0.18 0.065 2.98 6.23 L2P 48.8 40.9 23.0 0.15 112.9 0.30 0.048 3.08 5.66 L2K 60.0 32.9 35.0 0.14 128.0 0.18 0.026 2.74 6.61 L2PK 60.6 35.3 31.2 0.13 127.2 0.23 0.032 2.51 6.38 aCalcitic lime bDolomitic lime TABLE xx (Cont. ) Treatment Ca %§.e.§100 gEENsyotal P ?:ercenf) ASh Timothy hay — 1956 None 5.5 12.7 26.0 0.18 44.4 0.17 0.022 0.95 4.50 P 4.9 12.9 33.7 0.16 51.7 0.23 0.030 1.06 4.90 K 3.9 11.2 37.3 0.16 52.6 0.18 0.025 1.03 5.05 PK 3.6 10.7 41.0 0.19 55.5 0.24 0.026 1.13 5.49 14? 5.2 13.0 31.3 0.18 49.7 0.17 0.016 1.06 4.45 LIP 7.8 15.0 31.4 0.15 54.4 0.25 0.024 1.14 5.16 LlK 6.1 10.2 39.9 0.20 56.4 0.14 0.014 1.01 5.04 . LlPK 5.8 9.6 43.2 0.18 57.8 0.23 0.019 1.15 .5.75 : Lab 5.2 14.8 31.1 0.19 51.3 0.16 0.023 1.13 4.59 L2? 5.6 17.2 33.0 0.23 56.0 0.24 0.020 1.12 5.09 L2H 5.6 14.5 39.3 0.18 59.6 0.16 0.016 1.15 4.92 L2PK 4.6 15.1 42.6 0.20 62.5 0.23 0.022 1.10 5.55 Soybean hay - 1956 None 95.0 40.9 18.4 0.14 154.4 0.17 0.062 2.73 7.01 ) k P 106.9 47.3 18.0 0.09 172.3 0.25 0.057 2.85 7.96 K 90.6 36.5 28.1 0.13 155.3 0 20 0.064 2.79 8.05 PK 80.0 37.5 33.5 0.11 151.1 0 26 0.065 2.54 8.05 L1a 101.9 51.9 14.4 0.11 168.3 0.20 0.042 2.08 7.59 LIP 107.5 57.1 12.7 0.11 177.4 0.27 0.027 3.05 8.15 L1K 77.5 42.7 32.7 0.10 153.0 0.21 0.021 2.89 7.21 x LlPK 88.1 38.6 32.3 0.11 159.1 0.29 0.032 3.03 7.87 k L2b 78.1.48.3. 16.6 0.08 143.1 0.21 0.037 3.00 7.37 \ L2P 100.0 55.0 12.5 0.10 167.6 0.26 0.041 2.91 8.27 ‘ . L2K‘ 67.5 45.0 32.0 0.09 144.6 0 21 0.035 2.92 7.46 8 I L2PK 71.9 44.2 25.6 0.09 141.8 0.22 0.018 2.72 7.49 iii .-‘ 119 TABLE xx (Cont.) Treatment Ca :5. e ./1(l)(o 31:25) Total P (fitment? Ash Millet grain - 1955 None 0.45 4.6 5.0 0.11 10.2 0.35 0.0023 2.21 2.31 P 0.54 9.8 5.6 0.11 16.1 0.38 0.0025 2.05 2.60 K 0.51 6.5 5.4 0.13 12.5 0.33 0.0045 2.14 2.53 PK 0.45 9.6 5.4 0.12 15.6 0.34 0.0037 2.00 2.56 L1 0.40 10.8 6.2 0.11 17.5 0.34 0.0020 2.35 2.29 LIP 0.48 10.8 5.5 0.11 16.9 0.38 0.0010 2.16 2.29 L1K 0.46 13.4 6.1 0.10 20.1 0.35 0.0037 2.30 2.19 LIPK 0.54 10.8 6.9 0.11 18.3 0.431 0.0030 2.13 2.59 L2 0.49 10.8 5.8 0.12 17.2 0.38 0.0016 2.35 2.11 L2P 0.45 11.6 4.9 0.13 17.1 0.36 0.0020' 2.17 2.27 L2K 0.46 10.8 5.2 0.12 16.6 0.34 0.0020 2.26 2.18 L2PK 0.50 12.9 5.3 0.13 18.8 0.35 0.0028 2.17 2.50 Soybean grain - 1955 None 6.8 19.1 43.2 0.18 69.3 0.53 0.017 5.94 4.81 P 6.1 17.0 42.4 0.16 65.7 0.57 0.016 6.31 4.93 K 6.3 17.2 40.9 0.16 64.6 0.52 0.025 6.41 4.91 PK 6.1 19.1 40.8 0.19 66.2 0.62 0.019 6.46 5.40 L1 5.8 16.5 43.0 0.18 65.5 0.52 0.017 6.47 4.78 LIP 5.4 17.7 35.8 0.15 59.1 0.63 0.016 6.89 4.99 LlK 5.9 17.7 44.6 0.20 68.4 0.48 0.024 6.14 4.81 LIPK 5.9 14.6 43.5 0.18 64.2 0.58 0.017 6.75 4.84 L2 6.0 18.2 42.7 0.19 67.1 0.51' 0.016 6.21 4.62 L2P 6.4 19.8 39.6 0.23 66.0 0.56 0.016 6.20 4.66 L2K 6.5 19.1 42.8 0.18 68.6 0.49 0.020 6.11 4.78 LZPK 5.5 18.8 44.4 0.20 68.9 0.60 0.020 6.73 4.92 TABLE XX (Cont.) Treatment Ca fig K N9 Total P !5 N Ash (m.e./100 grams) (percent) 1L Millet grain - 1956 1 1 None 0.74 10.8 7.9 0.12 19.6 0.28 0.0060 2.36 2.34 m - P 0.76 11.1 9.2 0.15 21.2 0.38 0.0060 2.26 2.60 E 1 K 0.73 9.6 8.9 0.13 19.4 0.33 0.0080 2.34 2.39 56 PK 0.76 9.8 9.7 0.13 20.4 0.40 0.0093 2.20 2.55 .3 4 L1 0.79 9.6 8.7 0.14 19.2 0.31 0.0059 2.48 2.32 29 k LIP 0.97 16.0 9.0 0.13 26.1 0.38 0.0055 2.47 2.48 1J9 1 LlK 0.84 11.3 8.9 0.12 21.2 0.31 0.0080 2.54 2.42 K59 I: LIPK 1.00 13.4 10.0 0.13 24.5 0.38 0.0058 2.48 2.45 L2 0.71 16.5 8.2 0.13 25.5 0.28 0.0058 2.64 2.18 Z: : L2P 0.84 16.3 9.6 0.13 26.9 0.38 0.0025 2.62 2.37 ’18 r L2K 0.71 13.4 8.6 0.12 22.8 0.30 0.0039 2.66 1.97 L50 : L2PK 0.85 16.8 9.7 0.11 27.5 '0.38 0.0044 2.44 2.86 __ u __________________________________ ; Soybean grain - 1956 None 5.5 20.8 43.8 0.18 70.3 0.46 0.0080 6.09 4.61 P 5.7 20.6 41.9 0.19 68.4 0.61 0.0080 6.16 4.77 K 5.9 20.3 43.5 0.23 69.9 0.56 0.173 5.84 5.52 PK 5.4 18.0 43.5 0.15 67.1 0.66 0.143 5.80 5.12 L1 5.4 18.5 36.0 0.15 60.1 0.49 0.0070 6.34 4.16 LIP 6.1 19.3 35.5 0.15 61.1 0.63 0.0068 6.70 4.51 LlK 5.1 21.9 41.6 0.14 68.7 0.45 0.0020 6.09 5.56 L1PK 5.2 20.3 40.9 0.18 66.6 0.62 0.0023 6.37 4.63 L2 6.1 19.6 36.8 0.20 62.7 0.50 0.0073 6.55 4.41 L2P 5.2 17.7 33.6 0.19 56.7 0.60 0.0055 6.47 4.49 L2K 5.4 21.4 39.2 0.16 66.2 0.52 0.0083 6.08 5.68 L2PK 5.5 22.7 40.9 0.18 69.3 0.63 0.0055 6.12 5.01 121 TABLE XX (Cont.) Treatment Ca 35 K Na Total P Mn N Ash (m.e./100 grams) (percent) Corn grain - 1955 None 0.27 9.6 7.2 0.26 17.3 0.25 0.0018 1.75 1.24 p 0.31 10.6 10.2 0.35 21.7 0.37 0.0023 1.95 1.63 K 0.29 7.3 10.6 0.47 16.9 0.29 0.0022 1.69 1.40 PK 0.31 11.7 11.9 0.39 24.3 0.39 0.0037 1.97 1.64 L1 0.33 9.1 9.1 0.24 16.6 0.29 0.0026 1.97 1.59 LIP 0.26 9.3 9.0 0.15 16.7 0.36 0.0029 1.66 1.59 le 0.29 6.4 8.5 0.36 15.6 0.26 0.0014 1.77 1.27 LIPK‘ 0.26 10.1 10.4 0.17 21.0 0.36 0.0026 1.98 1.69 L2 0.30 10.1 6.0 0.16 16.6 0.26 0.0016 1.66 1.36 LgP 0.27 12.2 9.0 0.17 21.6 0.39 0.0025 1.91 1.60 sz 0.30 10.9 9.1 0.19 20.5 0.25 0.0032 1.63 1.47 L2PK 0.26 10.1 9.4 0.13 19.9 0.36 0.0030 1.76 1.67 Wheat grain - 1956 None 1.19 9.3 8.51 0.12 19.1 0.26 0.0059 2.19 1.43 P 1.04 13.4 9.4 0.11 24.0 0.36 0.0085 1.93 1.66 K 0.94 10.3 6.6 0.12 20.2 0.26 0.0095 2.34 1.69 PK 1.04 11.3 10.6 0.14 23.1 0.47 0.0145 1.76 1.96 L1 1.04 22.6 6.9 0.11 32.7 0.32 0.0036 2.29 1.71 LIP 1.00 16.4 9.9 0.10 27.4 0.44 0.0044 1.96 2.05 le 0.96 10.3 9.2 0.11 20.6 0.34 0.0075 2.30 1.61 LlPK 0.91 13.4 10.1 0.09 24.5 0.43 0.0063 2.01 2.17 L2 0.66 10.3 8.5 0.11 19.6 0.30 0.0066 2.41 1.73 L2P 0.66 11.3 10.0 0.11 22.3 0.43 0.0066 2.10 2.10 12x 0.66 6.2 6.7 0.09 20.7 0.32 0.0060 2.32 1.75 szx 0.79 9.3 10.5 0.09 16.9 0.44 0.0090 1.66 2.16 TABLE XX (Cont.) 122 W Treatment Ca Ms_ K Na Total P Mn N Ash (n.e./100 grams) (percent) Corn grain - 1956 None 0.26 6.2 7.1 0.11 13.7 0.23 0.0046 1.60 1.67 p 0.27 9.6 7.9 0.13 17.9 0.33 0.0046 1.69 1.87 x 0.25 6.8 6.9 0.12 14.1 0.25 0.0058 1.77 1.62 PK 0.26 7.6 6.3 0.12 16.5 0.32 0.0043 1.64 1.86 Ll 0.29 7.7 7.2 0.09 15.3 0.24 0.0039 1.65 1.77 LIP 0.20 10.2 7.9 0.15 18.5 0.33 0.0037 1.86 1.97 le 0.26 5.2 6.9 0.12 12.5 0.23 0.0034 1.63 1.67 116x 0.19 10.1 7.9 0.11 16.3 0.35 0.0040 1.69 1.96 L2 0.23 6.8 7.4 0.12 16.9 0.24 0.0023 1.79 1.70 L2P 0.24 6.1 7.8 0.14 16.3 0.32 0.0026 1.66 1.95 L2K 0.24 7.6 7.6 0.09 15.7 0.26 0.0033 1.67 1.67 LZPK 0.21 10.2 8.4 0.13 16.9 0.35 0.0043 1.88 1.64