.A STUDY OF SOME RELATIONSHIPS AMONG THE RESULTS OF SOIL AND TISSUE TESTS, FERTILIZER TREATMENTS, AND YIELDS OF SEVERAL CROPS GROWN ON ORGANIC SOIL Thesis for IIw Degree OI DI]. D. MICHIGAN STATE UNIVERSITY John C. Shickluna 1961 0-169 Date This is to certify that the thesis entitled A Study of Some Relationships Among The Results of Soil and Tissue Tests, Fertilizer Treatments and Yields of Several Crops Grown on Organic Soils. presented by John C. Shickluna has been accepted towards fulfillment of the requirements for ___..-....——-— . Ph. D. degree“; SCI] SClence -——.-.— __.,.__ February I L “ ‘ 151° 1" JUN 2:; 2007 A STUDY OF SOME RELATIONSHIPS AMONG THE RESULTS OF SOIL AND TISSUE TESTS, FERTILIZER TREATMENTS, AND YIELDS OF SEVERAL CROPS GROWN ON ORGANIC SOIL by 1&9 John CAMShickluna AN ABSTRACT Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Soil Science 1961 ABSTRACT A STUDY OF SOME RELATIONSHIPS AMONG THE RESULTS OF SOIL AND TISSUE TESTS, FERTILIZER TREATMENTS, AND YIELDS OF SEVERAL CROPS GROWN ON ORGANIC SOIL by John C. Shickluna Investigations involving the effect of rate and place- ment of fertilizers and Na—K interactions on soil test values, crop yields, and plant composition with several crops were undertaken at the Muck Experimental Farm in Clinton County, Michigan. The soil was classified as a Houghton Muck con- taining 85 per cent organic matter and having a pH of 6.3. The experiment involving the rate and placement of fertilizers has shown that the method of fertilizer place- ment did not significantly affect the yield of carrots, table beets, broccoli, or cauliflower. However, higher yields of late-planted cauliflower were obtained where the fertilizer was placed in a band below or to one side of the seed. An increase of 30 to 40 per cent in onion yields can be expected if the fertilizer is applied in a band 2 inches below the seed, rather than in bands 7 inches apart and 3-l/2 inches deep with a grain drill. The maximum yields of the crops studied were related to the residual soil P and K levels and supplemental fertilizer applications. Less extractable soil K was obtained from samples taken in the spring than in the fall. Time of sampling, however, 2 John C. Shickluna did not materially affect the amount of extractable soil P. The fertilizer ratio experiment has shown that high yields of onions can be obtained with residual soil P and K levels of 20 and 250 to 300 pounds per acre (0.018N CH3CCOH extractable), respectively when supplemented with a starter fertilizer containing 50, lO, and 20 pounds of N, P205, and K20, respectively. Also, the effect of residual N was reflected in onion yields. It was further shown that the same yield of onions could be obtained with different com- binations of N, P, and K. The water extractable N, P, and K analysis of the onion tissue showed that it is important to select tissue at a time when it will best correlate with plant needs. An increase in the water extractable P content of onion tissue resulted with soil applications of N as urea and ammonium nitrate. In the case of celery, it appeared doubtful that much increase in yield would be expected from additional amounts of P and K where the soil tests were around 35 pounds of P and 700 to 800 pounds of K per acre (0.018NCH3COOH extractable). The data from the fertilizer rate experiment showed that the same yield of sweet corn could be obtained over a wide range of residual soil P and K levels. Although there was no relationship between the amount of water extractable P, K, Ca, 3 John C. Shickluna Mg, Mn, and Na in the green corn tissue and the yield of sweet corn, there was an indicated trend that as the applied K increased the water extractable K in the green tissue increased and the Na decreased. Increased applications of soil K also resulted in an increase in water extractable Mn in the green tissue. Good correlations were obtained between K uptake, the amount of K20 applied, and the yield of broccoli, celery, and sweet corn employing the following method for the measurement of K uptake by the plant: Pounds of K Pounds of K Pounds of K obtained in the + applied as - obtained in the = K uptake spring sampling fertilizer fall sampling A comparison of extracting solutions showed that the inclusion of the flouride ion into the extracting solution increased the extraction of soil P. Increased amounts of soil P were also obtained by increasing the extractant to soil ratio. An experiment involving the sodium-potassium interactions of sugar beets showed that sodium appeared to be effective in substituting for K at low levels of soil K. As the per cent K in sugar beet tops increased the per cent Na and Mg decreased. The maximum yield of sugar beet roots occurred where the beet petioles contained 7000 parts per million of water extractable K. a John C. Shickluna Good correlations were obtained between soil K (0.0185 CHgCOOH extractable), water extractable K in the green tissue, total K uptake and the yield of sugar beet roots. The extracting solution employing 0.018 N CHBCOOH was shown to be a valuable tool in predicting yield response of sugar beets to applied soil K. Also, the large loss of soil K, due to crop removal, indicated the need for annual soil tests to determine fertilization recommendations for sugar beets. A STUDY OF SOME RELATIONSHIPS AMONG THE RESULTS OF SOIL AND TISSUE TESTS, FERTILIZER TREATMENTS, AND YIELDS OF SEVERAL CROPS GROWN ON ORGANIC SOIL by , A 5‘ 9 John CIMShickluna A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Soil Science 1961 TO My Wife This thesis is affectionately dedicated to my wife whose unfailing interest in the work was a constant source of encouragement and inspiration throughout its duration. ACKNOWLEDGMENTS The author wishes to express his sincere appreciation to Dr. J. F. Davis for his valuable counsel and constant interest during the course of this investigation. Grateful thanks are extended to Dr. R. L. Cook for providing the opportunity necessary for the writer to con- duct his course of study and to carry out this research. The writer also wishes to express his thanks to Mr. L. N. Shepherd for supervising the field phases of this study carried out by the personnel of the Michigan State University Muck Experimental Farm. Thanks are due Dr. E. J. Benne for the information provided on the analytical methods used in this investi- gation and to Drs. G. P. Steinbauer, K. Lawton, and R. Lucas for their constructive criticism of the manuscript. TABLE OF CONTENTS INTRODUCTION. REVIEW OF LITERATURE EXPERIMENT I. RATE AND PLACEMENT OF FERTILIZERS. Crops: Carrots, Table beets, Onions, Brocolli, and Cauliflower Procedure Results and Discussion EXPERIMENT II. FERTILIZER RATIO EXPERIMENT Crops: Onions and Celery Procedure Results and Discussion EXPERIMENT III. INFLUENCE OF FERTILIZER RATES ON SOIL TEST VALUES AND PLANT COM— POSITION . . . . . Crop: Sweet Corn. Procedure Results and Discussion EXPERIMENT IV. SODIUM—POTASSIUM INTERACTIONS. Crop: Sugar beets Procedure Results and Discussion SUMMARY AND CONCLUSIONS PAGE 25 25 25 27 43 1+3 43 A5 .87 87 87 88 102 lO2 IO2 104 138 PAGE EXPERIMENT I. . . . . . . . . . . . 138 EXPERIMENT II. . . . . . . . . . . . IAO EXPERIMENT III. . . . . . . . . . . . 142 EXPERIMENT IV. . . . . . . . . . . . IAA LITERATURE CITED . . . . . . . . . . . . 147 TABLE IO. LIST OF TABLES The influence of fertilizer treatment on the yield of carrots and table beets and the amount of extractable soil phosphorus and potassium, 1952. The influence of fertilizer treatment on the yield of onions and amount of extractable soil phosphorus and potassium, 1951, 1952, and 1953. The influence of fertilizer treatment on the yield of broccoli and on the amount of extractable soil phosphorus and potassium, 1955 and 1956. Relationships between K uptake, as measured by soil tests, the yield of broccoli and the amount of K20 and 5- -10— 2O fertilizer applied in 1955 and 1956.. . The influence of fertilizer treatment on the yield of cauliflower and on the amount of extractable soil phosphorus and potassium, 1957 and 1958. The influence of fertilizer treatment on the yield of onions and on the amount of soil phos- phorus and potassium, 1953 and 195A The influence of fertilizer treatment on the yield of onions, on the amount of extractable soil P and K, and the P and K in the green tissue, 1955 . . . . . The influence of fertilizer treatment on the yield of onions from the plots receiving the starter fertilizer at three levels of nitrogen which had been applied in 1954 Iheinfluence of fertilizer treatment on the yield of onions from the "fertilized half" of the plots at three levels of nitrogen and three levels of potash, 1955. A comparison in the response of onions to residual nitrogen and applied nitrogen where 100 and 300 pounds per acre of P205 and K20 PAGE 28 30 3A 37 A0 46 52 53 5A TABLE 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. were applied respectively to the "fertilized half" of the plots, 1955 The influence of fertilizer treatment on the yield of celery and the amount of extractable soil phosphorus and potassium, 195A. The relationship between the amount of residual soil potassium, the amount of potassium applied and the uptake of potassium by celery and its effect on yield, 195A The relationship between the amount of residual soil potassium and the uptake of potassium by celery and its effect on yield, 195A The relationship between extractable soil potassium, per cent potassium in the tissue, potassium uptake, and the yield of celery, 1955. The influence of fertilizer treatment on the extractable phosphorus and potassium content of the soil, the chemical composition (water extractable) of the green tissue, and the yield of sweet corn, 1955 The relationship between potassium uptake and the yield of sweet corn, 1956. Water extractable phosphorus, potassium, calcium magnesium, manganese and sodium relationships of green corn tissue, 1955. Correlation of extractions of soil phosphorus by various solutions. The yield response of sugar beets to salt (NaCl) on plots containing various levels of extractable soil potassium, 1955. The yield response of sugar beets to salt (NaCl) on plots containing various levels of extractable soil potassium, 1956. The effect of rates of application of KCl and NaCl on the amount of extractable soil phos~ phorus and potassium, the yield of sugar beet roots and tops, and the amount of potassium removed per acre, 1955 The pounds of extractable soil potassium and sodium per acre and the yield of sugar beet roots, 1956. vii PAGE 63 68 72 75 78 89 9O 98 100 106 109 120 viii TABLE PAGE 23. The amount of water soluble potassium and sodium in green sugar beet tissue, as related to soil treatment, 1955. . . . . . . . . 121 FIGURE IO. 11. LIST OF FIGURES A comparison of the extractable soil potassium obtained in the fall versus spring sampling by various methods of fertilizer placement. The effect of fertilizer treatment on the amount of nitrogen in the leaves of onions and the yield of bulbs The effect of fertilizer treatment on the amount of phosphorus in the leaves of onions and the yield of bulbs The effect of fertilizer treatment on the amount of potassium in the leaves of onions and the yield of bulbs The relationship between the yield of onions in 1955 and residual soil potassium at three levels of nitrogen applied in 1954. The relationship between the yield of onions and extractable soil potassium at three levels of nitrogen and potash A comparison in the response of onions to residual and applied soil Onitrogen where 100 and 300 pounds per acre of P and K2 0 were applied respectively to the ”fergiIized half” of the plots, 1955 The relationship between residual and applied soil nitrogen and the water extractable phos— phorus content of green onion tissue, 1955. The relationship between extractable soil potassium and the water extractable potassium content of green onion tissue, 1955 The adjusted yield response (AY) of celery to applied potash, 1954 . . . . . . The relationship between potassium uptake, as determined by soil tests, on the fertilized plots and the yield of celery, 1954 . . . . 33 48 49 5O 55 62 65 66 71 73 FIGURE 12. 13. 14. 15. l6. 17. 18. 19. 20. 21. 22. 23. 24. The relationship between potassium uptake, as determined by soil tests, on the unfertilized plots and the yield of celery, 1954. The relationship between K uptake (plant analy— sis) on the fertilized half of the plots and the yield of celery, 1955 . . . . . . The relationship between K uptake (plant analy- sis) on the unfertilized half of the plots and the yield of celery, 1955 . . . The relationship between K uptake (plant analy— sis) by celery and the pounds of potash applied, 1955 . . . . . . . . . . . The relationship between K uptake (plant analysis) on the fertilized and unfertilized plots and the yield of celery, 1955. The relationship between per cent potassium in the tissue and the yield of celery, 1955 The relationship between extractable soil potassium on the unfertilized plots and the yield of celery, 1955 . The relationship between potassium uptake, as determined by soil tests, and the yield of sweet corn, 1956 . . . . . . . . . . The relationship between extractable soil potassium on the unfertilized plots and the yield of sweet corn, 1956 . The relationship between extractable soil phos— phorus (0.018 N CH3COOH) and the yield of sweet corn, 1956 . . . . . . The relationship between extractable soil phos— phorus (o. 025 N HCl + 0.03 N NHMF) and the yield of sweet corn, 1956 . . . . . . . . The effect of salt (NaCl) and the interaction of salt (NaCl) and potassium on the yield of sugar beets, 1955. . . . . . . . . . . The effect of salt @301) and the interaction of salt (NaCl) and potassium on the yield of sugar beets, 1956. . . . . . . . . . . . PAGE 76 79 80 82 83 84 86 92 95 96 97 107 108 FIGURE 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35- 36. Soil potassium levels as related to fertilizer application and crop removal, 1955 and 1956. The relationship between extractable soil potassium and the yield of sugar beet roots, 1955. The relationship between extractable soil potassium and the yield of sugar beet roots, 1956. . . . . . . . . . The adjusted yield response (AY) of sugar beet roots to salt (NaCl) at varying levels of soil potassium, 1955 . . . . . . The adjusted yield response (ANY) of sugar beet roots to salt (NaCl) at varying levels of soil potassium, 1956 . . . . . . The relationship between the water extractable sodium content of green sugar beet tissue and soil treatment, 1955 The relationship between the water extractable sodium content of green sugar beet tissue and the yield of sugar beet roots from the residual potassium plots where no salt (NaCl) and 500 pounds of salt (NaCl) were applied per acre, 1955 The relationship between the yield of sugar beet roots and the water extractable potassium content of the green tissue, August 24, 1955 The relationship between extractable soil potassium and the uptake of potassium by sugar beet tops. 1955 The relationship between extractable soil potassium and total potassium uptake (tops + roots) by sugar beets, 1955 . . The relationship between extractable soil potassium and the per cent potassium in sugar beet tissue, 1955 The relationship between the yield of sugar beet roots and the per cent potassium in the sugar beet tops and roots, 1955. xi PAGE 112 113 114 116 117 122 123 126 128 129 130 131 FIGURE 37. 38. 39. 40. The relationship between the yield of sugar beet roots and total potassium uptake (tops + roots), 1955 The relationship between the water extractable potassium content of green sugar beet tissue and the pounds of K removed by sugar beet tops, 1955- The relationship between per cent potassium and sodium in sugar beet tops, 1955 The relationship between per cent potassium and magnesium in sugar beet tops, 1955 xii PAGE 132 134 135 137 INTRODUCTION The intensive cropping practices in use today have emphasized the need for soil tests and tissue tests as aids in determining fertilizer needs. Although soil testing and tissue testing are by no means new tools in diagnosing plant needs, great advances have been made in correlating these tests with crop yields. The problems in correlating a chemical test with the growth and yield response of a living mass of protoplasm are readily apparent. The growth of any plant or animal is affected by many factors that are interrelated and complex. It is important, therefore, that one becomes thoroughly familiar with the agronomic characteristics of a plant before a logical and practical interpretation of soil test results are made. Chemical soil tests give us practically no information about the variability of different plant species or of those factors affecting plant growth which are common to soils, such as drainage, water supply, physical condition, tillage methods, and soil temperature. Therefore, the results of the chemical testing of soils do not always correlate with plant growth or the response of plants to fertilization. Correlation of soil and plant tissue tests with crop response is highest when all the factors of plant growth other than nutrients, approach the optimal situation. Plant tissue tests are chemical analyses of the plant sap or sap extracts and represent very largely the nutrients not already combined in plant tissue at the time the test is made.(4l) Tissue tests should be used as a supplemental diagnostic tool in determining how to maintain optimum plant performance in any given environment. The principal objec- tives of determining the nutrient status of plants has been stated as follows (36): first, to aid in determining the nutrient-supplying power of the soil; second, to aid in deter- mining the effect of treatment on the nutrient supply in the plant; third, to study the relationship between the nutrient status of the plant and crop performance as an aid in pre- dicting fertilizer requirements; and fourth, to help lay the foundation for approaching new problems or for surveying unknown regions to determine where critical plant nutritional experimentation should be conducted. Organic soils constitute important potential soil reserves for the nation. 0f the 4-1/2 to 5 million acres of organic soils in Michigan, an area equal in size to the State of New Jersey and representing approximately one acre in eight, probably less than five per cent is farmed. However, they represent an important economic part of agricultural production for the state. Likewise, a large proportion of the organic soils located in Wisconsin and Minnesota have not been reclaimed.(l4) This investigation was initiated and carried out at the Michigan State University, Muck Experimental Farm in Clinton County, to study the relation- ship between soil tests, the amount of applied nitrogen, phosphorus and potassium and the uptake of these elements by the plant and their effect on crop yields. REVIEW OF LITERATURE The literature pertaining to the correlation of soil tests and tissue tests with crop yields on organic soils is somewhat limited. Bigger's (5) work with a Houghton muck in Michigan showed a highly significant correlation between the amount of phosphorus applied and the amount of phosphorus extracted from the soil by the following chemical reagents: 0.025N HCl + 0.03M NHNF, 0.1M H01 + 0.03M NHNF, 0.135N HCl and 0.018N CH3COOH. The correlation coefficients for these reagents were 0.943, 0.986, 0.915, and 0.967, respectively. He also found that the amount of potassium applied per acre showed a highly significant correlation with the amount of potassium extracted from the soil by any one of the following reagents: 23 per cent NaN03, 0.135N H01 and 0.018N CH3COOH. The correlation coefficient for these reagents were 0.640, 0.667, and 0.671, respectively. His work with green sugar beet and peppermint tissues revealed a seasonal variation in the composition of water extractable nitrate—nitrogen, phosphorus and potassium. The yields from these two crops correlated better with green tissue tests than with soil tests. Dawson (16), using sodium acetate-acetic acid solution buffered to pH 4.8 found the average potassium content of cultivated peat soils in New York to be 760 i 650 pounds per acre; and the average phosphorus content to be 200 i 210 pounds per acre. He estimated the safe level of soil test potassium at not less than 250 nor more than 350 pounds per acre; and the level of soil test phosphorus at not less than 50 pounds per acre. Dawson concluded that when a peat soil was fertilized with potassium at a constant rate per acre per year, the available potassium content of the soil, as measured by soil-test methods, adjusted itself within 3 to 5 years to the rate of fertilization and remained constant until the fertilizer”practice was changed again. A similar situation occurred for phosphorus providing the content of soil-test iron plus aluminum was less than 100 pounds per acre. When the iron and aluminum content exceeded 200 pounds per acre, the soil-test phosphorus was found to be 50 pounds or less per acre. The importance of the relationship between the iron plus aluminum content and the available phosphorus composition of peat soils was emphasized. Forsee (25) at the Everglades Experiment Station in Florida working with an Okeelanta peaty muck and using celery as the indicator crop found distilled water was preferable to 0.5 N CH3C00H as an extractant for soil phosphorus deter- minations. A significant relationship existed between the water soluble phosphorus and the amount of phosphorus applied to the soil. The same was true for potassium soluble in 0.5 N CH3000H. The maximum yield for celery grown on Okeelanta peaty muck was associated with 250 pounds of acid soluble 6 potassium and 30 pounds of water soluble phosphorus per acre. Many investigators (7,64,8) have compared a variety of soil extractants on mineral soils and correlated the "available" phosphorus and potassium obtained by these ex— tractants with crop yields. The results obtained by most workers have generally favored Bray‘s adsorbed phosphorus test (0.025 N HCl + 0.03 N NHNF). The work of Bigger (5) also showed that Bray’s adsorbed phosphorus test showed a highly significant correlation between the amount of phos- phorus applied and the amount of phosphorus extracted from an organic soil. Lawton and his co—workers (40), working with a mineral soil, attempted to correlate the response of legume hay to both phosphorus and potassium fertilization with the chemically measured available forms of these two elements. These investigators used the methods of Spurway (65), Bray (8), and Peech and English (52). They were unable to find any high degree of linear correlation between crop response and soil test value with either phosphorus or potassium. Similarly the correlation between plant growth response as measured upon percentage basis and exchangeable potassium did not appear significant. The work of Smith (64) showed that the use of any of the methods of Bray on a mineral soil provided a considerably clearer picture of phosphorus availability because the inclusion of fluoride in the extracting solution enabled the adsorbed phosphorus in the soil to be removed. An extracting ratio of one part soil to fifty parts of solution was more desirable for adsorbed phosphorus studies than the narrow ratio of one part soil to ten parts of solution. In contrast to the previous methods of soil extraction, Filman and co-workers (22) adopted a mechanical press for the removal of extracts from organic soils in Canada. Solutes expressed by pressure from the organic soils appeared to represent the nutrients available to the growing crops where methods used for mineral soils had failed to do so. These investigators reported evidence of mass movements of solutes in both horizontal and vertical directions in the organic soil. According to Hester (31) if a knowledge of the com- position of the soil solution that influences plant growth is desired, then a dilute chemical extractant is satisfactory. However, if the supplying power of the soil for a period of time is the information sought, perhaps the stronger extracting reagents are preferable. Eid, SE a; (21) have reported that at a soil temperature of 2000, the availability of soil phosphorus to corn plants was related to the inorganic phosphorus extracted by 0.025 N HCl + 0.03 N NHNF solution. At this temperature the organic phosphorus fraction, based on a l per cent K2003 extracting solution had no appreciable effect. However, when the soil temperature was increased to 3500. both the inorganic and organic phosphorus fractions were significantly related to the amount of plant-available phosphorus, but the variation in plant—available phosphorus was better explained by the organic phosphorus fraction than by the inorganic fraction. This can be accounted for on the basis that at the high soil temperature the organic phosphorus fraction underwent relatively rapid mineralization and the mineralized phosphorus served as a source of supply for the crop. At the low soil temperature the organic phosphorus mineralization was limited and the crop was, therefore, dependent on the phosphorus orginally present in the inorganic form. Kelly and Midgley (35) have proposed the mechanism of phosphate fixation to be the same with hydrated sesquioides as with finely ground kaolin. In both, fixation represents a physiochemical anion exchange equilibrium whereby phosphate ions replace exposed hydroxyl ions from the colloidal materials. The increase in pH of a colloidal system caused by phosphate fixation is taken as evidence that such an exchange of anions takes place. Furthermore, the removal of active iron and aluminum greatly reduced the capacity of soils to fix phosphate. Silicate and fluoride ions are capable of replacing hydroxyl ions, as evidenced by pH changes. The beneficial effect of silica on plant growth may possibly be due to its ability to remove fixed phosphate or to replace the hydroxyl ions and thus decrease phosphate fixation. Larsen, 33 al., stated (39) that when organic soils are first drained and placed under cultivation, a relatively high 9 percentage of applied phosphorus is available for plant growth. However, as these soils are cultivated for longer periods, a much smaller percentage of the applied phosphorus is available. The efficiency of uptake of applied phosphorus by plants gradually diminishes as organic soils become more decomposed. Two opposing factors function in the absorption of phosphorus by organic soils. Humic acid tends to prevent the absorption of phosphorus by the organic soil. In contrast the additions of iron and/or aluminum greatly increase the capacity of the soil to absorb phosphorus. The comparison of the humic acid contents of a cultivated and virgin muck by Larsen and his co- workers (39) showed the former to possess three times the amount of humic acid as the latter. On this basis one would expect the cultivated muck to have less fixation capacity. However, the sesquioxide content of the cultivated muck was fourteen times greater than that of the virgin soil. The increase in iron and aluminum masked the influence of the increase in humic acid content. Furthermore, it has been suggested that the sesquioxide content tends to increase continuously with age as a result of subsidence or mineralization, while the humic acid content tends to reach an equilibrium. Aging, which results in increased quantities of iron and aluminum then is primarily responsible for the increase in phosphorus fixation. Additional information by Larsen, g2 al., (37) has added support to this hypothesis. Where a virgin and cultivated muck soil were extracted with distilled water a decrease in the 10 ratio of soil to water resulted in an increase in the phos- phorus concentration of the virgin soil as compared to a decrease in the phosphorus concentration in the cultivated soil. This indicates that only a small part of the phosphorus was held in an insoluble form in the case of the virgin muck. The reverse of this occurred in case of the cultivated muck soil. The effect of other compounds arising from the decom- position of organic residues on phosphorus availability may be due to a combination of many factors. For example, Bear (4), has suggested that the humus extracts from soils increase the solubility of phosphorus resulting from (a) the formation of phospho-humic complexes that are more easily assimilable by plants; (b) anion replacement of the phosplate by the humate ion; (c) the coating of the sesquioxide particles by humus forming a protective cover and thus reducing the phosphate- fixing capacity of the soil; and (d) that certain organic anions arising from the decomposition of organic matter form stable complexes with iron and aluminum thus preventing their reaction with phosphorus. These complex ions release phosphorus pre- viously fixed by iron and aluminum by the same mechanism. Paul (51) has suggested that the inorganic alkali-soluble phosphorus (phOSphorus removed from the soil by digestion with 0.25 N NaOH) consists largely of phosphates of iron and aluminum and that the inorganic alkali-soluble and the exchangeable phos- phorus fractions may be regarded as equivalent to one another. He also pointed out that the organic alkali soluble (total phos— phorus-inorganic alkali soluble phosphorus) and the inorganic 11 alkali soluble forms of phosphorus are appreciable in both cultivated and virgin organic soils, contributing between them more than 70 per cent of the total phosphorus of the soils. The virgin soil contained a larger amount of inorganic alkali— soluble and organic alkali-soluble fractions than did the cultivated soil. The significantly greater yield increase of sweet potatoes obtained on the virgin soil was attributed to the greater percentage of these two forms of phosphorus in the virgin soil. It is suggested that the organic phosphorus fraction and the inorganic alkali soluble forms, the latter mainly as iron phosphate, are available to plants and that in the cropping of organic soils these two fractions were con— siderably reduced. Brown (10) using natural iron and aluminum phosphate obtained beetyields about 75 per cent of that resulting from the addition of superphosphate. Scarseth and Tidmore (60), on the other hand, obtained yields of sorghum from soils receiving iron phosphate of around 24 per cent relative to superphosphate. Bray (8) has pointed out that when the flouride methods of soil extraction have been applied to soils receiving applications of superphOSphate, the assumption that the added superphosphate is practically all fixed in unavailable forms is not substantiated by the results. Rather, much of the phosphate added is adsorbed on the colloidal complex in a form which is less soluble than in the original superphosphate but which is still rapidly soluble. Some workers (1,49) have suggested that soil organic constituents may be important as anion exchangers. Aderikhin (l) found that humus sorbed phosphate ions from monocalcium phosphate, whereas Doughty (20) found that soil organic matter did not play an important part in fixing phosphates. Mortland (49) showed that anion exchange resins sorb and exchange anions through free amino groups. He also showed that polyamino organic soil complexes and polyamino clay com— plexes exhibit anion sorption and exchange as shown in the following reaction, although they may be of minor importance: + _ _ + + H - Clay + Excess HgPON (~NH3—R—NH3 ) ngou -+ H3PON + _ + + _ Clay ( NH3-R-NH3 ) H2PON The work of Dean and Rubins (17) has shown that the phosphorus which accumulates in acid soils as a result of intensive fertilization is for the most part, relatively insoluble in dilute solutions of the strong mineral acids but can be readily replaced from soils by solutions containing certain anions. The majority of the common procedures for evaluating the phosphorus fertility status of soils are based on solubility rather than on anion exchange reactions. Thus, much of the phosphorus which has accumulated in ferti- lized soils is not considered when evaluating the phosphorus fertility. It has been suggested by these workers that the absorbed phosphorus should be considered when chemical data are used in the diagnosis of phosphate deficiency in soils. They stated that most of the applied phosphorus occurs as exchangeable phosphorus in acid soils, whereas in slightly alkaline soils containing a small amount of calcium carbonate 13 the phosphorus occurs mostly as salts of divalent bases (the calcium phosphates). Dean and Rubins (17) suggested the trans— ition zone to be in the neighborhood of pH 6.0 and pointed out that the exchangeable phosphorus fraction is important in those soils of pH less than 6.0. Lawton and Davis (43) noted that the phosphorus content of plants grown on organic soils was progressively depressed by successive increments of CaCo3. They attributed this decrease in per cent plant phosphorus caused by liming to a decrease in the proportion of H P04_ to HP04:= ions in the 2 soil solution. In contrast to studies on fixation, Larsen, 33 31- (38), conducted investigations on the leaching of applied labeled phosphorus in organic and mineral soils. After 15 inches of water were leached through the soil columns, phosphate reten- tion appeared closely correlated to the sesquioxide content of the soils and the apparent degree of decomposition. When labeled phosphate was mixed into the surface 2 inches of a 14-inch column of a virgin soil, 60 and 80 per cent appeared in the leachate from 15 and 30 inches of water, respectively. Lesser amounts of phosphorus appeared in the leachate from soils with greater sesquioxide contents and longer drainage histories while no phosphate was leached from the mineral soil or from the organic soil which had been drained for 15 or more years. The mechanism of potassium availability, as far as organic soils are concerned, appears to be less complex than that of phosphorus. Soil scientists have tried for many 14 years to develop chemical tests for ascertaining the potassium requirements of different soils for the production of various crops. It is probable that one of the factors contributing to the failure of chemical tests is the capacity of different soils to supply plants with different amounts of potassium from non-exchangeable forms. Stewart and Volk (66) pointed out that considerable potassium (an average of 2/3 of the potassium used by plants) comes from forms that were non-exchangeable at the beginning of the test, and the amount of non—exchangeable potassium removed from the different soils varied between 39 and 87 per cent of the total amount of potassium consumed by plants. Levine and Joffe (45) have suggested several mechanisms of potassium fixation,such as the reaction of potassium with "so-called” silicates to form difficulty soluble muscovite; or the migration of potassium from the surface of a colloid into the interior of the crystal. They postulated the possi- bility of potassium being fixed between the layers of the expanding and contracting c—axis of layer lattice minerals. They pointed out when montmorillonite layers are collapsed by heating to temperatures of about 5500 0., the ability of mont- morillonite to fix potassium diminished to the vanishing point. In general, with the decreasing ability of montmorillonite to swell reversibly, there was a decrease in the ability of the mineral to fix potassium. It is unlikely that any appreciable quantity of potassium is fixed by the organic material comprising a muck or peat soil. 15 Jones (34) concluded that the humus colloids possess, a very low fixing power for potassium. Likewise, Joffe and Levine (33) and Joffe and Kolodny (32) reported that organic matter did not fix potassium in a non-exchangeable form. The fact that potassium occurs in plants almost solely as soluble inorganic salts (48) is indicative of its free nature in organic material. Russell (59) reported that mulches increased the amount of exchangeable potassium in the soil and that potassium appeared to be the only mineral element showing a strong downward percolation. I Garmon (27) has shown that the relative rates of leaching of the different K salts were rather insignificant. He stated that the percentage K retained from an application of a K salt appeared to depend upon the amount of salt applied, the base saturation, and the base exchange capacity of the soil. Higher exchange capacities, increased K retention. The work of McCool (47) has shown that organic soils with a very low ash content, 10 per cent or less, were found to possess a very small capacity to fix potassium, but their capacity increased with their mineral content. Cook (11) has reported that efficient management of ferti— lizers is the art of feeding the plant rather than the soil. Broadcasting and mixing soluble phosphates with soil or spraying solutions on the soil surface result in maximum fixation and least efficienty as far as the immediate crop is concerned. That is because maximum contact is provided between the particles of fertilizers and the hydrated oxides which are a part of the soil and with which the phosphate ions readily combine. 16 Placing the phosphate in bands beside the rows of seeds is a more efficient way to apply them both as to crop yields and the percentage of the phosphorus the plants take up. Lawton, BE al. (42) showed that soluble phosphorus moves rapidly out of fertilizer granules but moves slowly away from the granules. The result is a highly concentrated spherical zone of soluble phosphorus around a granule as long as the soil is not disturbed. Roots may then penetrate that sphere and feed readily on the phosphorus in the soluble form. Robertson and his co—workers (58) have shown that the young corn plant has a high preference for the phosphorus applied in a band at planting time. .As the plant developed it depended more and more on the soil phosphorus. The degree to which the plant utilized the fertilizer was not directly pro- portional to the amount applied. When 20 pounds of phosphorus was applied per acre, 3.3 pounds was recovered in the above— ground part of the plant, whereas when four times as much was applied only twice as much was recovered. The rapid decline in the plants' intake of applied phosphorus from the fertilizer, which occurred irrespective of the amount applied, may be caused by one or more of the following factors: (a) chemical or bio- logical fixation or both of the applied phosphorus, which becomes less available to the crop as the season progresses; (b) the fertilizer band is no longer a favorable medium for nutrient adsorption because, for example, dehydration of the fertilization zone through root action or normal soil drying; (c) the ferti- lizer band applied at planting near the seed was in a zone l7 occupied only by cutinized nonadsorptive roots during the latter part of the growing season; and (d) the phosphorus needs of the plant are satisfied by absorption from the soil through its much enlarged root system, irrespective of any lo:alized areas of high nutrient concentration. Cook and his co—workers (12), have pointed out that when granular or pulverant fertilizer was banded in the soil, the uptake by plants of fertilizer phosphorus increased with an increase in the degree of water solubility of the fertilizer. Yields also increased with an increase in the percentage of the fertilizer phosphorus in the soluble form. For maximum up- take of phosphorus and top yields, fertilizers applied in bands should have at least 40 per cent of the phosphorus in water soluble form. 0n the other hand, fertilizers which contain no water soluble phosphorus should be thoroughly mixed with the soil and they should be pulverant rather than granular. Fertilizer placement work or methods of applying ferti- lizer in Michigan (15) have shown that if the fertility level in the soil is high enough, particulary of phosphorus, that 150 pounds of 5—20-10 starter fertilizer at planting time is sufficient for early development of the crop and for final yield. It was stressed that some fertilizer at planting time is neces— sary to get the crop off to an early start, even though at high fertility levels this stimulation of early growth may not be reflected in increased yield at harvest time. Other workers (56) have shown the first corn feeder roots grow downward at a 45-degree angle. These feeder roots soon 18 reach the starter fertilizer if it has been placed properly, that is--in a band 2 inches to one side and 2 inches below the level of the seed. This promotes early vigorous growth of the corn seedling and avoids the possibility of fertilizer salts coming in contact with the germinating seed. Their work has also shown that a corn plant can obtain maximum efficiency from a single band of properly placed fertilizer. It is not necessary to have starter fertilizer banded on both sides of the seed at planting time. It has been reported (53) that the corn plant produces almost half its total weight during one month of the growing season (in Ohio this occurred between July 20 and August 19); and that a 100 bushel corn corp (including total weight of above ground dry matter) required 143 pounds of N, 69 pounds of P, and 118 pounds of K per acre. It is obvious that if high yields are to be produced, the soil must be able to supply large amounts of plant food to the corn crop during the period of rapid growth. Soil fertility investigations for several crops under field and greenhouse conditions have been carried out by Forsee, e2 al. (26), on a new Everglades peat soil in Florida. The soil received 75 pounds of copper sulfate per acre and had the following residual soil tests: water soluble phosphorus, 8.4 pounds per acre; dilute acid soluble potassium, 58 pounds per acre; pH, 5.37. His findings with the various crops investi- gated are summarized as follows: l9 Broccoli: A fall planting of early green sprouting broccoli responded to applications of potash. Yields of plots where one-half the fertilizer was applied broadcast and one— half side—dressed, or where one—half was applied in the row and one-half side-dressed, were not appreciably different from those obtained where all the fertilizer was broadcast. Maximum yields of broccoli may be obtained on new Everglades peat soil when the water—soluble phosphorus level in the soil is approx— imately 8 pounds per acre and the dilute acid-soluble level is approximately 125 pounds per acre. Sweet Corn: A spring planting of Golden Security and F-M cross varieties responded well to potash applications. Fertilizer applications up to 80 pounds of K20 per acre in— creased the yield of unhusked marketable corn as much as 200 per cent, increased length and diameter of ears and decreased length of unfilled tips. However, no yield response was ob- tained to applications of phosphorus. There were no differ- ences between broadcast and band methods of application. In another experiment a spring planting of sweet corn on old, well-decomposed Everglades peat soil with a pH of 5.50, a water soluble phOSphorus level of 5.2 pounds per acre and a dilute acid—soluble potassium level of 127 pounds per acre responded to phosphate applications up to 72 pounds of P205 per acre. The phosphorus applications increased the yield of un- husked marketable corn as much as 100 per cent, decreased slightly the length of ears, increased the diameter of the ears, and decreased the length of unfilled tips. Low soil phosphorus 20 levels resulted in significantly lower stands. No yield re— sponses were obtained to applications of potash at this soil test level of K. Placing all the fertilizer in the row at planting also resulted in poor stands as well as decreased yields. Yields were significantly lower on plots receiving one—half of the phosphate at planting with the other half applied one month later. Side-dressed applications of nitrate—nitrogen had no effect on yields. These fertility experiments with sweet corn indicated that maximum yields of good quality corn may be obtained from broadcast applications of phosphorus and potassium in such amounts as to give a soil test level of 10 pounds per acre of water—soluble phosphorus and 125 pounds per acre of dilute- acid soluble K. Davis and his co—workers (13) in a fertilizer placement experiment on an organic soil found that fertilizer placement caused yields of onions and spinach to vary as much as 103 and 50 per cent, respectively. The results from this experiment indicated that fertilizers for these two crops should pref— erably be placed in a band 2 to 3 inches below the seed level. They also concluded that quantities of fertilizer in excess of 800 pounds of a 5-10—20 per acre should either be drilled in ahead of planting, broadcast on the surface, or plowed under. It was further concluded that the amount of fertilizer that could be safely applied in a band 2-inches below the seed depends on the amount of moisture in the seedbed at 21 planting time, the row spacing, and the performance of the fer- tilizer applicator in maintaining the desired depth of 2-inches below the seed throughout all of the planting area. Shear (62) has stated that at any level of nutritional intensity there exists a nutritional balance at which "optimum" growth for that intensity level will result. This means that at any given level of nutritional intensity, provided all nutrient elements are in proper balance, it is possible to obtain plants that appear normal in every respect and in which all metabolic processes are qualitatively normal. Maximum growth and yield, however, result only when the proper balance of nutrient elements occurs in combination with their optimum intensity. Thus, it is possible to have plants lacking symptoms of malnutrition, yet varying over a wide range in growth, or yield, or both. Under conditions of optimum balance, whether nutritional intensity is high or low, any critical change in the accumulation of one or more elements not accom- panied by appropriate changes in all of the other nutrient elements will result in an unbalanced nutrition. This will be reflected first in decreased growth and later, if the unbalance is intensified, in additional reduction in growth or yields, or in the appearance of leaf symptoms, or in all three ways. Magistad (46), on reviewing the literature, has reported that heavy applications of soluble fertilizers often increase the salt concentration of the soil solution to a degree injurious to plant growth, especially on sandy soils. Ferti- lizer applications of 1200 pounds per acre on Norfolk sandy 22 loam were reported to have increased the osomotic pressure of the displaced soil solution to about 14 atmospheres. It has been reported (46,57,38,2) that when the concen- tration of the soil solution is increased, the osmotic pressure gradient is decreased and water absorption goes on at a slower rate. Magistad (46) in his review suggested why a reduction in water intake decreases plant growth. These include salting out of cellular proteins, shrinkage of cell contents from the cell wall, and irreversibility of hydration of the cell contents. Haas (28) has reported that excessive NaCl or KCl decreased the magnesium content of plants and their chlorophyll content. He also suggested that an application of 100 pounds or less of chlorides per acre may seriously interfere with carbohydrate metabolism in tobacco plants by disturbing the amylolytic activity in the leaf, resulting in excessive starch accumulation in the leaves. Younts and Musgrave (72) have reported that corn growth was depressed at a chloride rate between 45 and 90 pounds per acre (60 to 120 pounds K20 as KCl) when row applied, with maturity being delayed by a somewhat lower chloride rate. Field experiments indicated that broad- casting the K01 alleviated the high chloride effect. These same workers (73) have shown the total nitrogen uptake by corn was depressed by high rates of chloride. This effect was primarily associated with nitrate-nitrogen. Also, the absorption of chloride was directly related to the amount applied. Haas (28) has also reported that increased salts in the medium were associated with decreases in the percentages of nitrate-nitrogen and protein nitrogen in the plants. 23 (York (71) has shown the addition of KCl and NaCl greatly increased the manganese content of corn and sudan grass. Bolle- Jones (6) showed that an increased K supply increased the con— centration of manganese in the stems and petioles of potato plants. He also suggested that one of the functions of K was to increase the mobility of manganese within the plant. Hartwell and Pember, as reported by Harmer and Benne (29), concluded that apparently certain of the uses of K, with some plants at least, may be performed by sodium, although there are certain principal functions of K which cannot be performed by any other element. If the amount of K is insufficient for the performance of these exclusive functions, probably maximum growth cannot be secured with any amount of sodium which may be added. Perhaps one of the more exclusive functions of K, in respect to sodium, is the necessity of adequate K in the plant for nitrogen to be made into proteins. It has been reported (54) with low K, protein formation is retarded, nitrates are not changed into proteins quite as fast or com— pletely, and ammonia forms of nitrogen accumulate. Scarseth (61) has suggested that since only the nutrient that enters the plant is effective in feeding the crop, it is important to know whether or not the plant is absorbing the nutrient. The failure of the plant to obtain the nutrient may depend upon many factors, such as, movement of the nutrient to the surface out of reach of the roots, leaching, fixation, poor root development, or deficient aeration and toxic root zones. 24 Tissue tests indicate the presence or absence of these nutrients in the conducting tissues of the plant in soluble, unastimilated form. When the intent is to ascertain the first limiting nutrient growth factor it seems important to differ- entiate between nutrients that have been assimilated and those that are unassimilated and still in the role of a raw material. It is for this reason the conducting-tissue parts are out instead of crushed or ground. The test does not show nutrients that have been assimilated into organic compounds. The plant is a dynamic system growing out of an equally dynamic soil. Conditions of nutrition vary within the plant with the state of growth, root development, and formation of the seed or fruiting body. Soil conditions also vary in regard to moisture, fertilizer placement, aeration, organic matter content, temperature, and other factors. Therefore, variations in the soluble nutrients in a plant at various stages of growth are to be expected. Nevertheless, if the nutritional status within the plant is determined frequently during the growing period, information regarding the factors of nutrition that are limiting at any particular period is obtained.(6l) Lawton (41) suggested the best program for diagnosis of chemical problems in soil fertility includes the integrated use of various diagnostic techniques, such as tissue testing, soil testing, and foliar symptoms. EXPERIMENT I RATE AND PLACEMENT OF FERTILIZERS Crops: Carrots, Table Beets, Onions, Broccoli, and Cauliflower Procedure The field work of this investigation, and the ones to follow, was carried out at the Muck Experimental Farm in Clinton County, Michigan. The soil was classified as a Houghton Muck containing 85 per cent organic matter and having a pH of approximately 6.3. Three fertilizer placement and rate experiments were initiated in 1949. Chantenay carrots, Detroit Dark Red table beets, and Downing Yellow Globe onions were grown. The fer— tilizer treatments are shown in Tables 1 and 2. The treat- ments in beet and carrot series were replicated four times and the onion series six times. They were maintained on the same area during the 4-year period. Soil samples from all plots were made up of 10 cores from the 0 to 6-inch layer. Each sample was screened through a 2mm. sieve and dried at room temperature. The carrot and table beet plots were sampled in May, 1952. They were tested for extractable P and K using 0.018 N CH3COOH extractant and a 1:4 soil to extractant ratio by volume. The onion plots were sampled in September 1951, May 1952, and 26 May 1953 to determine the effect that time of sampling and annual application of fertilizers had on amounts of available soil P and K. Yields of the various crops were determined. Broccoli (var. Green Sprouting Green Mountain) was planted in 1955 and 1956 on the area where onions were pre- viously grown (Table 3). All treatments werereplicated three times and a 5-10-20 fertilizer containing 3/4 per cent manga- nese was the basic fertilizer used. Fifty pounds of borax per acre was broadcast on all plots. The plots were sampled in the spring and fall of 1955 and 1956, respectively. The soil P was extracted by 0.025 N HCl + 0.03 N NHNF (Bray P1) and by 0.018 N CH3COOH (Spurway Active), and the soil K was extracted by 0.018 N CH3COOH as shown in Table 3. The soil to extractant ratio was 1:4 by volume. This same area was planted to cauliflower (var. Snowball) in 1957 and 1958 having received the same annual rates of fertilizer and the same methods of fertilizer placement as the broccoli and onion experiments. All treatments were replicated three times and received applications of boron and manganese at the rate of 3 and 10 pounds per acre, respectively. The plots were sampled in the spring of 1957 and were tested for extractable P and K. The soil P and K was extracted by 0.018 N CH3C00H having a soil to extractant ratio of 1:4; soil P was also determined by extracting with 0.025 N HCl + 0.03 N NHNF at soil to extractant ratios of 1:4 and 1:16. 27 The extractable P was determined by a colormetric method using the ammonium-molybdate—hydrochloric acid solution pro- posed by Dickman and Bray (19) and 1-ammino, 2—napthol, 4- sulphonic acid reducing agent developed by Fiske and Subbarow (2A). The extractable K was determined with a photoelectric colorimeter using a red filter (wavelength of 650 mu) and employing a sodium cobalti-nitrite procedure involving the use of 95 per cent ethyl alcohol. The uptake of K by broccoli was measured by determining the amount of potassium in the spring and fall on all plots using 0.018 N CHBCOOH as the extracting solution, and including the amount of K applied per acre as fertilizer. On this basis the following relationship was used as a measure of the uptake of K by the plant: Pounds of K Pounds of Pounds of K K uptake obtained in + K applied _ obtained in _ by the the spring to the the fall _ plant sampling soil sampling Results and Discussion Data in Table 1 show that rates of fertilizer application were reflected in the soil tests. Highest tests for P and K were obtained from the plots receiving the greatest amounts of fertilizer. However, no significant increases in yield of either carrots or beets resulted from any of the treatments. Placement of fertilizer did not significantly affect the total yield. However, when a serious infestation of "black root" occurred, better stands of beets were obtained on plots 28 .Ho>oH Rm one no memos couscon cocohommflo unmoflmacwfiw pmmofi ou whomon .Q.m.Q*** .dooc monocfinm\aum «mecca canals 2H confides nonaaflphom** .mcofiumOHaaop p509 mo mowcwo><* .mmma so: ooaasan Haom .m.z .m.z 0.8m m.w© H.: 8.: Aao>oa smvs*»m.m.n M soon soaoo em oom o.sm m.am smm can ma ma A 2a ooaaasn oow w.sm o.am sma mofi OH Ha soon soaoo am can moan oo ea com a.mm o.mm ama man ma ma **na soaaasm com o.mm m.sm sma mmH 3H Ha soon zoaoo am com a.wm m.am mma HNH Ha 3H soon soaoe am oom / 8.0m m.mm sma mma ma ma soon soaoo ea oom o.sm H.mm sma moH oH oH soon soaoo ea 00: whoop muonhmo whoop muchhmo mason mpOLLmo pCoEoomHm whom oaooe oaone manna , sod a a om-oa-o *ohom nod mcoe *opom mom mezzom mezzom mama «SDHmm¢Bom Dz< mbmommmomm QHom mum<90m ohm sumo efioflm can pmop Hflom** .mmmH ea om-oa-m one Hmma ca confides om-oa-:* mHH om a.ma w.sa sea m.m m.m m.: Aaoeoa smv .n.m.a commons beam 00: amm ems omm mam Ham an ea an M some sense an ooa c c an mam has eon cam cam on ma ma M stomasmawm am mmm comm zoaon :m 00w mmw mmw 0mm MHS mNm 3H mm mm M CH UmfiHHQQ 00w mam mam 0mm Ham mom HH ma NH CH cmHHHQQ 00w Fwd mm: Hmm mwm mwm HH ma 3H comm BOHmQ :m pcm mean :H 00m mam swm 00m mam mom OH ma ma comm Scamp :m 00w msm amm sow msm co: ma 2H we soon soaoo em com mwm ma: ohm CNN Fm: NH ma ma boom Scamp :H com 003 me .fiom mom 0mm HH 0H ma .Ummm BOHmQ :H Com mom 0mm wma 30H mom Ha HH 3H boom BOHmQ :H 00: mam mwfl mam mom wwm HH 3H 3H CH UmHHHLQ 00: wmma Hmma mmma mmma Hmma mmma mmma Hmma pCoEoomHm whom whom mom mwmn M m hoe ccsoauom mo ponsdz **ohom pod mezzom *mpfldom mmma Cam ammma .Hmma «EDHmmdeom 92¢ mbmommmcmm QHOm mqmdeo¢m9xm mo EZDOZ< Qz< mZOHZO mo quHN mmB zo BzmzedmmB mMNHQHemmm mo mozmbflmzH Mme m mqmde 31 of "side—dress" fertilizer, or to the fact that fewer nutrients were removed because of lower crop yields. By comparing treatments which involved the same methods of placement, the data indicate that 1951 yields increased directly with rate of fertilizer application. The residual soil P and K also increased when more ferti— lizer was applied. The amount of extractable P in the plots receiving 1,600 pounds of fertilizer per acre was significantly higher than in any other plots in 1951. Similar results were obtained in 1952 except where 800 pounds of 5—10-20 was applied 1 inch to the side and 2-inches below the seed or where the fertilizer was drilled in. The same degree of significance, however, did not apply to the extractable soil K but a general increase in K was observed with increased rates of fertilizer application. The highest yields were obtained in 1951 and 1952 on the plots receiving BOOpOUHdSIOf fertilizer per acre placed 3 inches below the seed and 800gxnnkh3per acre drilled in. Yields resulting from this treatment were significantly higher than all the other treatments in 1951 except where 800 pounds of fertilizer per acre was placed 3 inches below the seed. In 1952, significantly higher yields were produced on plots receiving this treatment except where 800 pounds of fertilizer per acre was placed 1 inch below the seed, 2 inches below the seed, and where 400 pounds was placed 1 inch below the seed and 400 pounds was drilled in. Onions required a higher level of soil P and K for high yields than did carrots or table beets. Where the soil test 32 was about 15 pounds of P and 200 pounds of K per acre, the onion crop required 800 pounds of 4-10—20 or 5—10-20 per acre annually to produce high yields. Time of sampling is important in interpreting soil test results. In general, less extractable K was obtained from samples taken in the spring than in the fall as shown in Table 2 and Figure I. In all cases except one, the soils sampled in the fall of 1951 had higher amounts of extractable K than did those sampled in the spring of 1952 and 1953. Time of sampling did not materially affect the amount of soil P. There was no accumulation of P or K from 1951 to 1953 inclusive, even at the higher fertility levels. From the data shown in Table 2 and Figure I as much as 60 per cent of elemental K was lost from the 0—6 inch layer between fall and spring sampling dates. Probably the displaced K was lost in the drainage water and/or removed from the surface layer and subsequently deposited at some lower depth in the profile. Similar results werelwxxnfixxiby Bigger (5). He found that the applied K was leached from the surface layer and moved down to the lower depths. These results suggest that fall applications of K on organic soils can lead to serious losses of K. Likewise, it would be inadvisable to attempt to build up residual K to extremely high levels on these soils. As shown in Table 3, there was no significant difference in yields of broccoli in 1955 or 1956, regardless of the rate i I A N A IN ’1‘ f \ ’\ IFV 0...» I!“ IV Allh .l \\\a .\~ ~!\\-u 2 \V\~v«vb \xv\xva\ -.\ \.\ z s \\\a.\\ ..»-.\.n\\ I. .\ \5. ...A\\/\\\\ v-\ FALL LEVEL 500 __ D [1 SPRING LEVEL a I: O O (J . In 0 ~— 13‘4<)C)“ egg ‘2 O = \— t». {_ .3; “J : ”555 .55 t ‘5’:' ' -. :5 <1 577 w, o: 3 O O - «3: hJ fig. if 0- 1.. ¥ 4 ’w m E E 200— "2 H d I): 'Q. Q as L“ .3 3 3’ s g s 0. 0) JD m; ‘3 S? Q m +f‘ + + Z IOO - ‘7 an on to m m J; H 513: m a: D Q = : : 2 = - - ~‘- = - m - . . . . . . ‘ . O O 0 O o o o 0: O o o i o . s s s 8 § 8 s 8 . 2 “a: O .'. METHODS AND RATES OF APPLICATION OF A. 5-IO-20 FERTILIZER Figure l. 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O Essence mmNHHEmmm mo 82535 are m mqmdB 41 A similar situation resulted where 800 pounds was drilled in, or where a split application of 800 pounds was placed 3 inches below the seed and 800 pounds was drilled in. Plots receiving the 800 pound application rate placed 3 inches below the seed gave significantly higher yields than those where 800 pounds was drilled in, although it was inferior to those treatments receiving the same amount of fertilizer placed 1 inch below the seed. Similarly, the plots receiving the 800 pound rate placed 1 inch to the side and 2 inches below the seed gave significantly higher yields than those where 800 pounds was drilled in or where only 400 pounds was placed 1 inch below the seed. Both the plots from the treat— ment receiving 800 pounds placed 3 inches below the seed, plus 800 pounds drilled in and the treatment where only half these rates were applied produced significantly higher yields than where the 800 pounds of 5-10-20 was drilled in. The fact that higher yields of cauliflower were obtained in 1957 from plots where either all or part of the fertilizer was placed in a band below or to one side of the seed, as compared to the drilled in method of fertilizer placement, emphasizes the importance of band placement of fertilizer on the yield of late planted crops. The methods of fertilizer placement, rather than the level of P and K appeared to be responsible for the differ— ence in yields of cauliflower obtained from the different treatments in 1957. This is apparent since there was no significant difference in the amounts of extractable P or K between plots receiving the various soil treatments. a. 42 No significant difference occurred in the yield of cauli— flower due to treatment in 1958. The extractable soil P and K data in Table 5 were quite variable. However, a general trend of increased levels of soil P and K resulted with increased applications of these elements to the soil. The higher soil P and K levels obtained from the plots where 400 pounds of 5-10-20 was drilled in as compared to the other methods of fertilizer placement may possibly be ascribed to sampling errors. During seasons of high fertikizer response a soil test of 8 pounds of P obtained by the 0.018N CH3COOH soil extractant or 22 and 34 pounds employing 0.025N HCl + 0.03 N NHNF as the extracting solution at soil to extractant ratios of 1:4 and 1:16, respectively, and 50 pounds of K per acre supple— mented with an application of 800 pounds of 5—10-20 per acre annually placed apprOXimately 2 inches below the seed, was sufficient to produce high yields of cauliflower. The ratios of P removed by 0.025 N NCl + 0.03 N NHNF at soil to extractant ratios of 1:4 and 1:16 relative to that removed by extracting the soil with 0.018 N3CH COOH at a soil to extractant ratio of 1:4, were 2.4:1 and 3.721, respectively. EXPERIMENT II FERTILIZER RATIO EXPERIMENT Crops: Onions and Celery Procedure A fertilizer ratio experiment was initiated in 1952. Downing's Yellow Globe onions was the crop grown. Annual applications of nutrients equivalent to those in 1,000 pounds of one of the following fertilizers were made on quadruplicate plots in 1952 and 1953: 0—20-10, 5—20-10, 10-20—10, 0—20—20, 5-20—20, 10-20-20, 0—20—30, 5-20—30, 10-20—30, 0—10—30, 5—10—30, and 10-10—30. These fertilizer treatments were repeated on one-half of each plot in 1954. (From 1940 to 1951 this area had received 1,000 pounds of 0—10-30 fertilizer every year.) A starter fertilizer containing 50 pounds of N, 10 pounds of P205,and 20 pounds of K20 was applied to the remaining half of each plot. The fertilizers were applied at planting time in a band 2 inches below the seed. The amounts of N, P205, and K20 applied are shown in Table 6. The soils from the plots receiving the various treat- ments were sampled in September 1953 and May 1954. The samples were made up of 10 cores from the 0— to 6 inch layer of an 11 x 60 foot plot. .Each sample was screened (2 mm. sive) and dried at room temperature. 44 Green-tissue tests were made on the onion leaves on July 16 and August 1. The object was to determine the rela— tionships between the quantity of applied N, P, and K, the uptake of these elements by the plants, and the yield of onion bulbs. The leaves from 10 onions were selected per plot for green tissue analysis. The samples were kept cold by means of dry ice until the extractions were completed, as outlined by Bigger, RE 31- (5). The water soluble N was determined colormetrically by using 10 per cent brucine in chloroform. The water soluble P and K were determined by the methods previously mentioned for determining soil P and K. Sampling errors were determined for soil and green tissue tests. The soils from the same onion experiment were again sampled in the spring of 1955 and analyzed for available P and K employing 0.018 N CHBCOOH as the extracting solution at a soil to extractant ratio of 1:4. The yields from the plots receiving the various treatments were determined. Green tissue samples were collected on July 18, 1955 and water extractable P and K were determined as previously outlined. The results are shown in Tables 7, 8, 9, and 10, and Figures 5, 6, 7, 8, and 9. A K rate experiment (0, 400, 800, and 1200 pounds K20 per acre) with Utah 10B celery was started in 1953. Two hundred pounds of P205 were applied in 1953 and again in 1954, 45 on one-half of each of the plots. The other half of each plot was unfertilized in 1954. Fifty pounds of borax per acre was used annually on all plots. The results are shown in Tables 11, 12, 13, and 14, and Figures ll, 12, and 13. Another celery experiment was initiated in 1955 to deter- Inine the relationship between available soil K, total K in the plant tissue, and the yield of celery. The air dried celery tissue was finelyggxnnwiand extracted with neutral normal ammonium acetate containing lithium chloride as the internal standard. The K contained in the filtrate was evaluated flame photometrically (50). The experimental area was previously fertilized with 2000 pounds of 0-10-30 per acre, annually, from 1941 to 1952, inclusive. Applications of nutrients equivalent to those in 2000 pounds of 0-10-0, 0-10—20, 0—10—40, and 0-10—60 ferti- lizers were made on one-half of each plot. The remaining half of each plot received no fertilizer application. All treatments were replicated three times and the results are shown in Table 15 and Figures 14 to 18, inclusive. Results and Discussion Rates of fertilizer application in the onion experiment were reflected in the soil tests, as shown in Table 6. Less extractable K was obtained from samples taken in the spring than in the fall. The time of sampling did not materially affect the amount of extractable P. The fertilizers did not significantly affect the yield of onions in 1953. However, in 1954, the plots receiving 100 46 .Omm OOCSOQ om ocm .momm OOCSOQ OH ‘2 Occsoa om mchHmucoO momHHHunom ampmmpm m maco mcH>fiooo9 muoaa EON9 OHOH%*** .mpom hog momHHHpmom 90 condom ooo.H mcH>Hoooa muoHQ thm OHOH%**. .OmmH .H pm5w5¢ One OH OHSO co coxmu moaascm ozmmHB .qmmH mm: Ohm mmma nonsouaom CH OOHQEOO OHHow .mcoHpOOHadoh hsom 90 owmwo>¢* .m.z OmH .m.z O.OH m.sO O.: O.OH AHo>cH sOO .O.m.H mmO smO HHOH aOm OHm sH OH OOm-OOH-OOH amO sws OOOH Omm OOm OH OH OOm-OOH-OO OmO OHO OOO smm OOm OH OH OOm-OOH-O OOO OOs OOOH aOm OOm mm am OOm-OOm-OOH OmO was OOOH aOm sOm Om Om OOm-OOm-OO mOO Oms sOOH mOm Osm mm Om OOm-OOm-O saO OOs mmHH Omm OOm mm OH OOm-OOm-OOH OOO mws HOHH sOm Osm mm Om OOm-OOm-OO OOO Oss OOOH Omm HOm Hm sm OOm-OOm-O OOO OOO mmHH OsH sOm Om am OOH-OOm-OOH mam HHO amHH AWH OOm mm Hm OOH-OOm-OO OOO Owe OmHH H H mmm OH Hm OOH-OOm-O ***HOOH asaOOH OOOH OOH OOOH OOH OOOH Omx-OOmm-z .mz .ooom m2 .ooom . .o. . - OOH .mOOH .mOOH sou d LOQ Oman meson om mo LOQESZ x m : «OHHOSCCO choc Hoe moczom *mpmou HHom whom mom mocdom JmQH 92¢ mmma qZmem¢Bom 92¢ mbmommmomm AHOm mum¢eo¢mem mo BZDOE¢ 998 20 92¢ mZOHzo mo 999H> 999 20 EZmSB¢mmB mMNHqHBmmm mo mozmquzH mmB w mgm¢9 47 pounds N, 100 pounds P205, and 300 pounds K20 per acre yielded more than did any of the other treatments and in most cases the differences were significant. The plots receiving only the starter fertilizer, 50, 10, and 20 pounds per acre of N, P205, and K20, respectively, pro— duced higher yields in 1954 in every case than did those plots receiving the basic fertilizers without the starter. It is evident from these data that the residual N, P, and K were sufficient to produce high yields in 1954 when only a starter fertilizer was used. Figure 2 shows that on July 16 the water extractable N in the leaves of the onions increased directly with the amount of N applied. There appeared to be a relationship between the amount of N in the onion leaves and the yield of bulbs although the relationship did not exist with onions sampled on August 1. It is important to select tissue for sampling at a time when the N, P, and K will best correlate with plant needs. Figure 3 shows that the water extractable P in the onion leaves sampled on July 16 did not entirely reflect the increased soil P, but in every case except one it was related to the yield of bulbs. This relationship did not exist with the onions sampled on August 1. There was less concentration of P in the onion tissue sampled on August 1 than in that sampled on July 16. This same relationship existed between the two tissue sampling dates receiving the starter fertilizer. The data in Figure 4 show no relationship between the amount of K in the onion leaves and the yield of bulbs. 8 <3 N i; WATER EXTRAOTABLE N(ppm) IN GREEN-T ISSUE BAGS PER ACRE a o o I u: 48 900 - 800 700 500 400 200 SAMPLING DATES — JULY l6 — - JULY l6 S -0-0 AUG. I .0»- AUG. l S -No l l , l I OJ I l I L l l .5 I O .5 I O .5 I O .5 I 2 2 2 2 2 2 2 2 I I I I I 2 2 2 3 3 3 3 3 3 FERTILIZER RATIOS The effect of fertilizer treatment on the amount of nitrogen in the leaves of onions and the yield of bulbs. 8 ? BAGS PER ACRE a o o I U) 49 § 200 IOO WATER EXTRACTABLE P(ppm) IN GREEN-TISSUE .0 ' '°. .o" SAMPLING DATES \ 50+ V — JULY I6 —— JULY I5 5 -e-e AUG. I .00.. AUG. I S I I I I l I I l 1 IL 1 1J O .5 I U .5 I O .5 I O .5 I 2 2 2 2 2 2 2 2 2 I I I I I I 2 2 " 3 C. " ‘J 3 3- FERTILIZER RATIOS Figure 3 The effect of fertilizer treatment on the amount of phosphorus in the leaves of onions and the yield of bulbs. 8 (I) ‘1 i WATER EXTRAOTABLE N(ppm) IN GREEN-T ISSUE BAGS PER ACRE a C) C) I m % 8 ‘1’ § 3 o um «m § § SAMPLING DATES — JULY Ie —— JULY l6 s -«--amal .0»- AUG. I S Hau¢3 -mh— -53.. .— mwo- Nah" m...— IVCD~ umb— u-— u-h- u- h 2 3 FERTILIZER RATIOS The effect of fertilizer treatment on the amount of nitrogen in the leaves of onions and the yield of bulbs. 51 Likewise, the applied soil K was not reflected in the leaves of the onion tissue. Generally there was more water extractable K in the onion tissue sampled on August 1 than in the onion tissue sampled on July 16. The reverse relationship occurred for the water extractable N and P, as shown in Figures 2 and 3, respectively. The soil and tissue test results and the 1955 onion yield data are shown in Table 7. The "fertilized half“ of the plots resulted in higher yields than the half receiving starter fertilizer (50 pounds N, 10 pounds P205, and 20 pounds K20 per acre). To simplify the discussion the plots which received the initial treatments annually are designated as the "fertilized half” of the plot. No significant interactions between P and K or between N, P, and K were obtained on the "fertilized half” of the plots or on the plots receiving the starter fertilizer. There was, however, a significant difference in the yield of onions between rates of N at the l per cent level on both the "fertilized half" of the plots and on those receiving the starter fertilizer (Tables 8 and 9). The relationship between the yield of onions and the residual soil K at three levels of N on the plots receiving the starter fertilizer is shown in Figure 5. Where no nitrogen was applied the previous year (1954), the yield increased directly with an increase in available K up to approximately 180 pounds of K per acre. A decrease in yield resulted when the available K increased beyond this amount. 52 TABLE 7 THE INFLUENCE OF FERTILIZER TREATMENT ON THE YIELD OF ONIONS, ON THE AMOUNT OF EXTRACTABLE SOIL P AND K, AND THE P AND K IN THE GREEN TISSUE, I955 Pounds per acre Pounds per acre PPM in green Number of annually since tissue* 50—pound bags 1952 P K p K per acre 0—200-100{S ** 22 136 65 1150 596 0-200-100?F 24 177 98 1400 771 5o-2oo-1oo(s 22 165 98 1000 701 50-200-100 F 26 153 120 1650 838 100—200—100 S 23 146 - — 749 100-200—100 F 23 158 174 1150 872 0-200-200 S 25 173 - - 742 0—200-200 F 28 222 135 1800 811 50~200-200 S 26 184 66 1250 711 50—200-200 F 30 212 80 1800 806 100-200—200 S 25 204 144 1150 77 100—200-200 F 31 217 135 2150 839 0-200-300 S 23 225 78 1950 673 0-200-300 F 24 254 145 2000 730 50-200-300 S 23 219 80 1500 784 50—200-300 F 26 258 98 2250 852 100—200-300 S 23 218 90 1650 739 100-300-300 F 25 286 75 2100 861 0-100-300 S 17 236 35 1750 671 0-100-300 F 22 336 66 2150 785 50-100-300 S 22 213 42 1950 746 50-100-300 F 23 271 90 2750 790 100—100—300 S 21 201 127 2300 803 100-100—300 F 28 304 184 2500 837 L.S.D.E5%leve1ggsg6.2 51.2 - - 101.7 L.S.D. 5%leve1 F 7.8 56.8 - — 93.0 *Green tissue sampled on July 18, 1955. **(F) refers to plots receiving 1,000 pounds of fertilizer per acre. (S) refers to plots receiving starter fertilizer containing 50 pounds N, 10 pounds P205, and 20 pounds K20 per acre. TABLE 8 THE INFLUENCE OF FERTILIZER TREATMENT ON THE YIELD OF ONIONS FROM THE PLOTS RECEIVING THE STARTER FERTILIZER AT THREE LEVELS OF NITROGEN WHICH HAD BEEN APPLIED IN 1954 Pounds applied per acre Number of 50— in 1954 ' Pounds_per acre pound bags N 2205 K20 P K Per acre 0 200 100 22 136 596 50 200 100 22 165 701 100 200 100 23 146 749 O 200 200 25 173 742 50 200 200 26 184 711 100 200 200 25 204 775 O 200 3OO 23 225 673 50 200 300 23 219 784 100 200 300 23 218 739 L.S.D. (5% level) — — 6.2 51.5 101.7 Average for Nitrogen Levels 0 - - - - 670 50 - - - - 732 100 - - - - 754 L.S.D. (5% level) 51.0 54 TABLE 9 THE INFLUENCE OF FERTILIZER TREATMENT ON THE YIELD OF ONIONS FROM THE "FERTILIZED HALF" OF THE PLOTS AT THREE LEVELS OF NITROGEN AND THREE LEVELS OF POTASH, 1955 Pounds applied per acre Number of 50- in 1955 Pounds per acre pound bags N P205 K20 P K per acre 0 200 100 24 177 771 50 200 100 26 153 838 100 200 100 23 158 872 O 200 200 28 222 811 50 200 200 30 212 806 100 200 200 31 217 839 O 200 300 24 254 730 50 200 300 26 258 852 100 200 300 25 286 861 I5é°2éve1) — - 7.9 56.8 96.0 Average for Nitrogen Levels 0 - - - - 771 50 - — - - 832 100 - - - — 857 L.S.D. (5% level) 46.4 a.» .zmma Ca ooaaaam :mwoppfic mo mao>ma owns» 38 Edammwuoa Hwom Hasnfimmp one mea CH mcoHco mo namam on» cmmzumn aficmcofiumaop one .m mpzmfih AIOOUnIo 2 90.03 mmod mun. x m..m<._.oM3 2 Q2301 00 Ill 1000 3m>md 2 Q2301 0 001. Loom 389V 83d SQVE ONHOd-OQ :IO HHEWIIN 56 The yield of onions obtained from the plots receiving no N in 1954 was 500 fifty pound bags per acre. The available soil P and K,as indicated by extracting the soil with 0.018N CH3000H, were 22 and 130 pounds per acre, respectively. Where 50 pounds of N was applied per acre at the same level of soil K, the yield of onions was increased by 145 fifty pound bags per acre. These values were obtained by extrapolating the yield response curves for the 0—N and 50 pound N treatments back to the "Y” axis. Since there was no significant differ— ence in the level of available soil P the increase in yield may be ascribed to the 50 pounds of applied N per acre. There was a positive linear yield response between the 50 pounds of applied N and increased levels of soil K. The yield response curves for the 0-pound N treatment and the 50 pound N treatment intersected at approximately 151 and 192 pounds of available soil K per acre. It is apparent that the same yield of onions can be obtained with different combinations of N, P, and K. From these data approximately 23 pounds of P and 192 pounds of K per acre are capable of producing the same yield of onions as when supplemented with an additional 50 pounds of N. The initial response to N occurred at the lower level of available K. The price of the various carriers of N, P, and K may determine what com- bination of these three elements would be used in order to obtain optimum yields. Extrapolation of the 100 pound N treatment back to the "Y” axis indicated that high yields of onions were initially obtained at the lower levels of available soil K. However, the yield did not increase to any extent with increased soil K. The residual effect from the application of 100 pounds of N per acre in 1954, increased the yield of onions in 1955 by 85 fifty pound bags per acre over the 50 pound N application and by 230 fifty pound bags per acre over the 0 pound N treat- ment at a level of approximately 22 pounds of P and 130 pounds of K per acre. The yield response curves for the 50 and 100 pound nitrogen treatments intersected at around 207 pounds of available K per acre. It appears from these data that the same yield of onions can be obtained with different combinations of N, P, and K even at the higher nitrogen levels. Approximately 23 pounds of P and 210 pounds of K per acre and the residual N remaining from a 50 pound application of N the previous year are capable of producing the same yield of onions as the treatment receiving 100 pounds of N the previous year. These data show that the residual N (N applied the previous year) affected the yield of onions even though 50 pounds of N was applied in the starter fertilizer. A similar relationship is shown in Figure 6, in contrast to the effects of residual N, P, and K the data in Table 9 and Figure 6, show the relationship between the yield of onions and available soil K at three levels of applied N and K. The yield of onions obtained on the ”fertilized half" of the plots in 1955 were consistently higher than those 58 .nmdpoa can nowopuac no uaoboa cons» pd eaanndvon Haom caneuoenpxe and acoaco no wand» on» coozuen adnmcoauaaon one .0 opswfim fooonzo 2 20.8 mmoq «mm x mamfloqmexm 10 8230.1 0mm 03 03 08 em om. c: on _ _ fl — q _ d ouv. Eon 4m>m|~ 2 02301 002III| 4M>M4 2 02301 00 Ill qm>mq 2 02301 0 \ M03. 08 /l x \ a 08:80. \X cuxuoon III... I: ov J 00h own 005 Omm Omm 000 383V 83d SQVB ONnOd-OQ :10 838"!le receiving starter fertilizer, consisting of 50 pounds of N, 10 pounds P205, and 20 pounds K20 per acre. This is shown in Tables 8 and 9 and Figures 5 and 6. The general shape of the yield reSponse curves on the plots receiving the 0, 50, and 100 pound N treatments and the 200 and 100, 200, 300 pounds per acre of P205 and K tively, were similar to those receiving the starter fertilizer 20, respec— only. The yield of onions from the plots receiving no N increased directly with an increase in available K up to approximately 220 pounds of available K per acre. The sudden decrease in yield as shown in Figure 6 may have been due to an unbalanced condition in the plant. Walsh and Clarke (69) have shown a K induced Mg defici- ency of tomatoes. Excessive K fertilization resulted in depressed growth and yield together with symptoms typical of Mg deficiency, the severity of the disorder depending upon the degree of unbalance between the concentration of K and Mg in the leaves. York (71) has shown that K greatly reduced absorption of other major cations, particularly Ca and Mg. The decrease in onion yields at the higher K levels may possibly be explained on this basis. Wallace (68) has reported that Mg deficiency in acid soils of the Netherlands is much increased by adding K salts and still more by adding N as an ammonium compound, probably from the standpoint of NH4 being a competing ion. In this experiment the nitrogen was supplied as a combination of urea and ammonium nitrate which may have complimented the K in decreasing the uptake of Mg by the onion 60 plants at the 100 pound N treatment. It is possible NH4 and K antagonism on the uptake of Mg and/or an insufficient supply of available P or K at such high N levels were responsible for limiting the yield of onions at the 100 pound N treatment. The former hypothesis has been supported by Bear (3). He showed the absorption of N in the NH“ form resulted in a reduction in the K + Ca + Mg + Na content of plants. A comparison of the yield response of onions from the plots receiving the starter fertilizer relative to those receiving applied N at three levels of application, where 100 and 300 pounds per acre of P205 and K20 were applied, respec- tively, is shown in Table 10 and Figure 7. There was a positive linear yield response with increaSing levels of N on both the plots receiving the starter fertilizer and on the ”fertilized half" of the plots. The yield of onions was increased on the plots receiving the starter fertilizer, from 671 fifty pound bags per acre to 803 fifty pound bags per acre where no N and 100 pounds of N, respectively, had been applied the previous year. The soil P and K levels on these plots ranged from 17 to 22 and from 201 to 236 pounds per acre, respectively. There was no significant difference in either the P or K soil test values. The yield of onions on the "fertilized half” of the plot receiving no N was 785 fifty pound bags per acre, and increased “linearly to 837 fifty pound bags per acre where 100 pounds of N had been applied annually. The ”fertilized half“ received 100 pounds of P205 and 300 pounds K20 per acre. There was no Si — nificant difference in soil P between N treatments; however, 61 mosam zaawsccm owx mo mossom oom no mccsog ooH mafia .mmma new amma . Nmma 0cm mbmm mo wagon 00H msgfimoop 33.0 on mega CS 1;. ‘ .mmmH 8cm mmmfl an own weapon oom new momm Ca pmNHHHupmm nonempm wcH>Hoomn muoaa on whence Amv* l‘ .m.z m.mm m.» H.HoH m.nm «.0 Aam>ma mmv .n.m.q smm :om mm mom How am 00H om» Hem mm 0:» me mm om mm» 0mm mm .1 Hem 0mm SH 0 Amy opom non Amvx **Amvm Amy whom pom Amvx *Amvm whom mwmn ocsomnom whom you mossom mwmn cczoanom whom 900 mUGSOQ pom mccsoa CH mo ponssz . mumou HHom mo 909852 women Hfiom Ho>oa z HmeHcH mmma .mBOQE mo =mq m amNHqummm= mme on wnm>Heommmmm QMHQmm< mmmz o & Qz< o 1 mo mmo< mmm mQZDom oom 02¢ OOH mmmm3 zmwomEHz QmHQmm< 92¢ zmwomHHz A<* - .0.2 .0.2 .m.z - - - - - - Aam>0fl e00 .0.m.n 0.: 0.00 0.00 0.0: 000 0000 0000 00 s: 00 000a-000-00 0.0 0.00 0.00 0.00 000 000 00s 00 0: 00 000-000-00 0.0 0.0: 0.00 0.00 H00 000 000 00 00 00 000-000-00 0.0 0.00 0.0: 0.0: 000 000 H00 00 00 m0 0-000-00 E000 0000 0000 0 m 0 **0 ***snw 0000000000 02 0000000000 00 .0000 :0 002 :0 .0000 00 002 00m . 0000 - z 2 m 0000 p00 mvcsom *0000 000 0009 *0900 E00 mUCSom A JmOH «ZDHmm290m 02¢ mbmommmomm QHOm mumdeo¢mem mo 823022 mmB 02¢ wmmqmo mo QQme MEB 20 BZMEB¢MME mMNHQHBmmm mo mOZMDQmZH M29 HH mum<8 69 on the fertilized plots in 1954 were obtained where 800 pounds of K20 was applied per acre and the spring soil test showed 768 pounds of soil K per acre. The residual soil K, after crop removal, was 698 pounds per acre. The highest yields on the plots not fertilized in 1954 were obtained where the Spring soil test showed 768 pounds K per acre and the residual soil K, after crop removal, was 393 pounds per acre. The variation in the soil extractable P on the fertilized plots, before and after fertilization, was from 29 to 39 and 33 to 47 pounds per acre, respectively. The extractable P in the unfertilized plots varied from 27 to 35 pounds per acre. It is doubtful that much increase in yield of celery can be expected from additional amounts of P and K where the soil tests are 30 to 35 pounds of P and 700 to 800 pounds of K per acre. To determine the error of sampling involved in the experi— ments previously described, soil samples were taken from 76 plots at the Muck Experimental Farm that had received a uniform fertilizer treatment for a 14 year period. The extractable soil P and K were determined. The standard deviations from the mean were 10 i 0.3 and 161 i 2.4 for the extractable soil P and K, respectively. From one to 10 onion plants were taken at random from one plot of the onion fertilizer placement experiment and the water extractable N, P, and K determined. The standard deviations rom the mean were 563 i 16.7, 60.5 i 4.1, and 3504 i 21 for the N, P, and K,respectively. 70 These data Show that the error of sampling for both the soil and plant tissue was low. Probably five onion plants per plot would be sufficient to obtain a representative sample. The following relationship was used to determine the response of celery in the above experiment, to various levels of potash: ALY’: Yf + r — Yr where,.AY’= the adjusted yield or the yield response of celery to applied potash Yf + r = the yield obtained from the fertilized half of the plot. Yr = the yield obtained from the unfertilized or residual half of the plot. The relationship between the yield response of celery to four levels of potash, as determined by the above method, is shown in Table 11 and Figure 10. The largest yield response (8.5 tons of celery per acre) was obtained from the 400 pound application rate where the available soil K was 332 pounds per acre. Additional incre- ments of applied potash (800 and 1200 pounds per acre) resulted in a decreased yield response as the available soil K increased. The correlation coefficient for this curvilinear (quad— ratic) relationship was 0.433. The uptake of K by celery (Table 12 and Figure 11) was measured by determining the amount of extractable K in the Spring and fall samplings, using 0.018 N CH3000H as the soil eXtPactant and including the amount of K applied per acre as fefltilizert' This may be expressed as follows: 71 .4004 .nuapoa 003090 on 18300 00 A>oe emv .o.m.q m.m om ewe we om mmmm 6mm -- 04m om onooom 3.6 em emm mm mm oomm o4: mooe mmm mm Aevooom m.m m: mwa mm so ooqm mm: mew mmm ma ”ovommm H.o e: oem . mm em .mmm: so: as» oom ma flavommm o.m om omm mm om mmm: oom How mam :4 onooma :.m om mme we we mmmm mam mam mmm :4 Aevooma :.m m: ewe mm so ooem mam ewe ome ma onome w.m m: mam mm so ooom w oom sow mma m ***Aevoms **0pom :2 82 w: mo x m m , m *m, whom poo too r, 47 2 ext. om-oe-o msoe momma» Coopw CH COHHHHE poo mpemm meow poo mezzom . mo mezzom mmme .zmoo emmzm mo oquw may 62¢ mommHe 2mmmo mme mo Amen/18.46% ewe/15 2338.128 aeoezmmo mes. .fiom mes. mo ezmezoo amemaeom 62¢ momommmomm mqmeeoamexm are zo ezmzeamme mmNHqumme mo mozmoamzH mme ma Mdm<8 TABLE 16 THE RELATIONSHIP BETWEEN POTASSIUM UPTAKE AND THE YIELD OF SWEET CORN, 1956 90 Pounds of Pounds K per a0re O-lO-3O ‘ per acre Spring Applied Fall Uptake Tons per acre 750 254 188 165 314 6.4 750 247 188 182 290 6.9 750 103 188 178 150 3.8 1500 178 375 480 148 5.6 1500 220 375 503 167 5.8 1500 192 375 474 168 4.2 2250 391 563 741 325 7.0 2250 316 563 516 475 2.7 2250 302 563 804 173 5.8 3000 426 750 825 501 3.8 3000 439 750 935 2+011L 5.9 3000 480 750 1008 372 6.3 91 3000 pounds of 0-10-30 fertilizer per acre and having residual soil P and K levels of 23 and 393 pounds per acre, respectively. It is doubtful, however, that these high rates of fertilization could be justified relative to the small yield increase obtained from their application. From these data approximately the same yield of sweet corn can be obtained over a wide range of residual soil P and K levels, since approximately the same yield was obtained from residual soil P tests of 12 and 20 pounds per acre, and 190 and 340 pounds of K per acre. Current fertilizer recom- mendations for sweet corn grown on muck soils in Michigan (23) suggest that no additional P and K need be applied to the soil when the soil tests indicate 20 pounds or more of P and 240 pounds or more of K per acre. ~The mean K uptake values for sweet corn on the fertilized half of the plot, as determined by soil tests, were 77, 82, 137, and 252 pounds per acre; their respective yields were 5.8, 6.1, 6.4, and 5.4 tons per acre. These data show the yield increased as the uptake of K increased to 137 pounds per acre. A decrease in yield resulted as the K uptake in- creased beyond this value. However, there was considerable variation in plot data in regards to K uptake. A curvilinear (quadratic) relationship existed in 1956 between K uptake, as determined by soil tests, and the yield of sweet corn. The correlation coefficient for this relation— ship was 0.832 and was significant at the l per cent level \Figure 19 and Table 16). The maximum yield of 7 tons per 92 .32 .58 poo... no 33s 23 vs. 839 33238 5253 6230338 2a. .S tau: mmuq mun. moZDOa 2_ quhas x 00w 00m 00V 000 OON OO. O . . . . . . r0 um n? .- 0 m.0uum o N8 _OOO.O|8m,.mO.O+ mm”... "xxx *.* wa On 8 v m CHEM 383V 83d SNOJ. NI CHI. r. _. 1.- . ._ . w. .15 «IMF. l a .. $3.: . , iii 334.6525...“ 23 .mt. new..-" 93 acre was obtained at a K uptake value of 325 pounds per acre, and the available soil P in the spring sampling was 34 and 73 pounds per acre, as indicated by the Spurway Active (0.018 N CH3COOH) and Bray Pl (0.025 5 H01 + 0.03 w NHMF) soil extracting solutions at a soil to extractant ratio of 1:4, respectively. The higher rates of applied K were generally reflected in higher plant uptake values for K. The highest K uptake value of 501 pounds per acre was obtained from the plots receiving 750 pounds of applied K per acre; and the sweet corn from the plots receiving 188 pounds of K per acre reflected the least amount of K taken up by the plant, 150 pounds per acre. The decrease in yield obtained with higher uptake of K suggests a possible unbalanced nutritional condition within the plant. The high amount of available K may have inhibited the uptake of calcium and magnesium although no deficiency symptoms were observed. During the season from June 1 to August 15, the respec— tive railfall for 1955 and 1956 was 12.5 and 9.8 inches. In general, a much more even distribution of rainfall occurred in 1956, while a particularly heavy railfall occurred in the last half of July in 1955. This might suggest the possibility that the uptake of K by sweet corn was inhibited due to poor aeration created by excessive soil moisture. The relationship between pounds of available soil K per acre (0.018 g CH3000H extractable) on the unfertilized half of the plots in the spring of 1956 and the yield of sweet corn 94 is shown in Figure 20. The correlation coefficient for this relationship was 0.515. Although this coefficient was not statistically significant at the 5 per cent level, the general trend that existed between increased soil K and increased yields of sweet corn emphasizes the importance of soil tests in reflecting yield response. It is possible that this coef— ficient would have been significant had there been a greater number of values involved in the correlation. Correlation coefficients of —0.285 and 0.696 were obtained for the relationship relating the pounds of soil P extracted by the Spurway Active (0.018 N CH3COOH) and Bray Pl (0.025 N HCl + 0.03 N NHuF) tests and yield of sweet corn from the unfertilized half of the plots (Figures 21 and 22). The latter relationship was statistically significant at the 5 per cent level. The extracting solution employing 0.018 N CH3COOH showed no significant relationship between soil P and the yield of sweet corn, since the negative correlation coefficient was not significant. The extracting solution employing 0.025 N HCl + 0.03 N NHuF, however, indicated a positive linear rela— tionship between soil P and the yield of sweet corn. These data may be interpreted that the adsorbed forms of P extracted by 0.025 N HCl + 0.03 N NHnF are available to the plant and are an important source of P for plants grown on organic soils. As shown in Table 17, no significant linear relation— ships were obtained between the following: 95 .wmmH achoo 3003» no mama» on» new cacao conaafiunomqs on» no afiauoduoa Haou manwuoahpxo coozpon nanncoaumHon «:9 .0m ohdem mmo< awn. v. m4mOH ucmo poo H Ono pm ucmoflmficmfim** .HO>OH ucmo poo m on» p6 unmeamficwfim* H m.m #66:.6 6.Hm xmme.6 + p.66 u s Azufiv 662 m mowo + m>aco< stanzam .\ .m> Awauav mmz 2mo.o + O>Huo< mmzhsom H e.m **mme.6 6.mm x464.m + 4.6m u w heuav m>ape¢ smzasem Ix .m> AQHHHV mmz z mo.o + O>Hu6¢ mmzmsdm Hum.H **m66.6 6.6H xmwm.H + H.HH u s Awnav m>apo¢ smzaaem (. .m> Aznav mmz 2mo.o + O>Huo¢ mMZLSQm H m.H **6m6.6 6.66 xemm.6 + 6.6: n_w mwauav 662 m 6.6 + m>au6< mmzps m .m> Amanav m mmpm H 6.6 **sme.6 6.4H x66:.6 + m.6- n s meuav m mz m 6.6 (x + O>Hpo< mass: m .m> Amauav m mmpm Hum *qu.6 6.6m xsww.6 + H.6e n s I Aeuavam seam .m> ,\ Awa Hy a 62 z m6.6 + 6>Hpe¢ smzaaam H m.H *6Hm.6 6.6H 2466.6 + 6.SH u.w ARHHV m «z m 6.6 + O>Hp6¢ hmzpsam .m> Annav m mmpm H m.m **m6e.6 m.6m Amm6.a + 6.66 n.w. “quay Hm seam .m> Awauavam scum HN6.: **6mm.6 e.6 2e46.6 + H.m-u.w. Aquav 6>Hpo< sezssam .m> Amauavam swam Hum.H **m©>.o m.s xmw:.o + 0.: n.® Azuav m>fiuo< mmznsam .m> Aquavam mmpm Umpomppr m p mhu coaumswo comameEoo 66 afipsm coammmpwmm smocflq n» mZOHBqum mDOHm¢>.Nm mbmommmomm QHOm mo mDOHBo Bray Pl (1:16) vs. Spurway Active + 0.03 N Na F (1:4) > Spurway Active + 0.03 N NaF (1:16) vs. Spurway Active (1:4)) Spurway Active + 0.03 N NaF (1:4) vs. Spurway Active (1:4)? Bray Pl (1 16) vs. Spurway Active + 0.03 N NaF (1:16)) Bray P1 (1:4) vs. Spurway Active + 0.03 N NaF (1:4)7 Spurway Active + 0.03 N NaF (1:16) vs. Spurway Active + 0.03 N NaF (1:4)‘7Spurway Active + 0.03 N NaF (1:16) vs. Bray P1 (1:4). As shown in Table 18, the inclusion of the flouride ion into the CH3000H increased the extraction of P from the soil. Increasing the soil to extractant ratio also increased the extraction of soil P. The Bray Pl (0.025 N H01 + 0.03 N NHNF) extracting solution appears satisfactory and is currently being used in Michigan for the extraction of soil P (soil to extractant ratio of 1:8) on both organic and mineral soils. EXPERIMENT IV SODIUM—POTASSIUM INTERACTIONS Crop: Sugar Beets Procedure An investigation involving the response of crops to salt (NaCl) at varying rates of potash was established in 1951. The original experimental plot design consisted of a randomized block which was later split, thus permitting half of the plot to receive an application of 500 pounds of salt (NaCl) per acre; the other half of the plot received no salt. Both the salt treated plots and the plots receiving no salt received an application of 1000 pounds per acre of the following fertilizers: 0—10—10, 0-10—20, 0-10-30, and 0—10-60. These rates were equivalent to 100, 200, 300, and 600 pounds of potash per acre. Celery and table beets were grown on these plots from 1951 through 1954. In 1955 these plots were again split thus permitting the following treatments: residual K, residual K plus 500 pounds of salt, K alone, and K plus 500 pounds of salt. The plots were cropped with sugar beets (var. U. S. 400) for two consecu- tive years. All treatments were replicated four times. Plots were 11-1/2 feet by 26-1/2 feet in size. The fertilizer was applied with a grain drill and all treatments received the 103 equivalent of 40 pounds (13.6 per cent) fertilizer borate per acre. The soils were sampled on May 17, 1955 before the second split was initiated. Soil P and K were extracted by means of 0.018 N CH3COOH at a soil to extractant ratio of 1:4. The green sugar beet tissue was sampled on August 24, 1955 and analyzed for water soluble Na and K. The method previously described for the extraction of these elements in corn was employed, and the quantitative determinations of Na and K were carried out on a Beckman Model DU Spectrophotometer with a flame attachment at wavelengths of 589.3 and 766.5, respectively. The air dried sugar beet tops and roots were finely ground and extracted with neutral normal ammonium acetate containing lithium chloride as the internal standard. The K and Na in the filtrate were evaluated flame photometrically. Magnesium was precipitated as MgNHNPON, ignited to MgQPNO7 and evaluated gravimetrically, subsequent to the removal of Ca by repeated precipitations with (NH4)2C2O4° The soils were again sampled in May of 1956, and analyzed for available Na and K, employing 0.018 N CH3COOH as the soil extractant at a soil to solution ratio of 1:4. The chemical procedure employed for the evaluation of these elements was the same as that previously described for their evaluation in green sugar beet tissue. In 1955 and 1956, planting dates were May 20 and June 2, respectively, and they were harvested on November 8, 1955 and November 7, 1956. 104 Results and Discussion The effect of applications of Na (NaCl) and K (K01) and the interactions of Na and K on the yield of sugar beet roots for 1955 and 1956 are shown in Tables 19 and 20, and in Figures 23 and 24, respectively. Uniform levels of P were maintained across all plots in the experiment as shown in Table 21. The highest yield of sugar beet roots in 1955, 25.1 tons per acre, was obtained from the plots which had a residual soil test of 298 pounds of K, and which had received 500 pounds of NaCl per acre. The next highest yield of 23.5 tons per acre was obtained from the plots receiving 1000 pounds Of 0—10-60 per acre, where the:Esidua1 soil K was 212 pounds. As shown in Figures 23 and 24, with one exception, both in 1955 and 1956, the plots receiving the combination of salt plus fertilizer out-yielded all others. In 1955 the appli- cation of 500 pounds of NaCl per acre on the residual plots, which had previously been fertilized with 1000 pounds of 0—10-60 fertilizer per acre, was sufficient to produce high yields of beets when the residual K test was 298 pounds per acre. In 1956, however, the soil K test on these same plots was only 111 pounds per acre and an application of 1000 pounds of 0—10-60 per acre produced higher yields than either the 500 pound NaCl treatment, or where 500 pounds of NaCl plus 1000 pounds of 0-10—60 were applied. The order of magnitude of the fertilizer ratios producing the greatest yield in 1955 and 1956, when applied at the rate of 1000 pounds per acre were as r6116ws: 0-10-60 > 0—10-30 > 0-10-20 > 0-10-10. THE YIELD RESPONSE OF SUGAR BEETS T0 SALT (NaCl) 0N PLOTS CONTAINING VARIOUS IEVELS OF EXTRACTABLE SOIL POTASSIUM, TABLE 19 1955 105 Pounds of extractable Yield of sugar beets in tons per acre soil K per acre on Half Of plot Half of plot Yield salt treated plus receiving receiving K response fertilized half NaCl plus K only to NaCl of plots (YS + f) (Yf) (.ASYU 264 20.8 23.5 — 2.7 312 25.3 25.8 - 0.5 272 22.6 22.9 — 0.3 346 23.1 ' 21.9 1.2 126 17.8 23.1 5.3 150 22.1 19.9 2.2 168 25.2 20.8 4.4 156 23.9 19.1 4.8 112 22.4 18.6 3.8 112 21.9 19.1 2.8 104 19.1 17.7 1.4 116 23.4 19.5 3.9 84 20.1 9.0 11.1 90 18.5 13.9 4.6 - 84 18.5 15.4 3.1 104 10.0 16.8 — 6.8 106 TABLE 20 THE YIELD RESPONSE OF SUGAR BEETS T0 SALT (NaCl) 0N PLOTS CONTAINING VARIOUS LEVELS OF EXTRACTABLE SOIL POTASSIUM, 1956 1 Pounds of extractable Yield of sugar beets in tons per acre soil K Per acre 0“ Half of plot Half of plot Yield salt treaged plus receiving receiving K response fertilifzel thalf NaCl plus K only to NaCl 0 p O S (Ys + f) (Yf) (lSY) 137 12.2 13.7 - 1.5' 110 10.4 10.4 0.0 275 12.8 13.4 — 0.6 27 12.3 11.9 0.4 31 11.6 11.4 0.2 192 11.7 11.2 0.5 48 11.3 11.5 - 0.2 17 13,7 10.5 3.2 17 11.6 11.2 0.4 13 11,5 10.0 1.5 17 9.9 8.5 1.4 10 10.4 9.0 1.4 107 .mmmH .numun human mo vamah on» no Edamoduon 6:6 Afloazv same no sofipouamusa on» can Afiomzv pass so sought one .mm shaman mm0< mun. 00239”. 000. no whdm MIL. ._.< 0949.4 mm~...__._.mmu 0_I0_u0 0N|0_..0 Onto-10 00I0_I0 0. 36. . pa: m A 7% . v/h , t . ..... 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(380V 83d SNOJ.) A V 118 An inverse relationship existed between the yield response of sugar beets to NaCl and increased levels of soil K both in 1955 and 1956. A correlation coefficient of -0.666, which was significant at the l per cent level, was obtained for this relationship, in 1955 when the LY value of -6.8 was eliminated from the correlation, and —0.400 when this value was included. The £5Y value of -6.8 does not con— form to the other values and it appears that an error may have occurred in processing these data. As shown in Figure 29, a linear correlation coefficient of —0.547 and a curvilinear correlation coefficient of 0.654 were obtained for this relationship in 1956. These data suggest that Na is capable of substituting for part of the K required by sugar beets, particularly at the lower levels of available soil K. Whether the element assists in the functions of K in the matabolic processes of the plant, or whether it has, in certain plants, functions that it alone can best fulfill, is a question yet to be answered (30). Timm (67) has shown that a substitution of Na for K, in the nutrition of sugar beets, occurred in soils with a low initial exchangeable K content treated with 100 pounds of potash. Lehr (44) has suggested that in the event of a K shortage, most of the Na went to the foliage, where it set free a certain quantity of K for use in other parts of the plant. This situation was not apparent in these data (Table 21). 119 As shown in Table 22, there was a trend toward lower levels of extractable Na from the residual plots which had received no fertilizer application other than 500 pounds of NaCl per acre as compared to the plots receiving both ferti- lizer and NaCl. These data tend to indicate the larger uptake of Na by sugar beets in the absence of less available soil K. The relationship between water soluble Na and K in green sugar beet petioles and soil treatment in 1955 is shown in Table 23 and Figures 30, 31, and 32. In general, green tissue obtained from the plots receiving 500 pounds of NaCl contained the greatest amount of water soluble Na. The decreasing order of magnitude of water soluble Na contained in the green petioles from the plots receiving the various fertilizer treatments was as follows: NaCl only), NaCl plus fertilizer“) residual Na and KC) fertilizer (K20) only. The amount of Na obtained in the green petioles was fairly constant both from the plots receiving 1000 pounds of the various fertilizers, and also from the residual plots. However, the tissue from the plots receiving 500 pounds of NaCl, and those from the plots receiving the NaCl plus 1000 pounds of 0-10—60, 0—10-30, 0—10-20, and 0-10-10 generally contained larger amounts of Na where the least amount of K was applied. As shown in Figure 31, the application of 500 pounds of NaCl per acre to the plots receiving no K (residual plots) THE POUNDS OF EXTRACTABLE SOIL POTASSIUM AND SODIUM TABLE 22 PER ACRE AND THE YIELD OF SUGAR BEET ROOTS, 1956 120 Pounds per acre* Treatment K Na Tons per acre fiesidual plots 0-10-60 + s** 111 268 9.9 o-1o-3o + s 48 313 8.7 0-10-20 + s 16 257 8.0 0—10-10 + s 24 226 8.6 0-10—60 119 117 7.6 0—10-30 52 135 7.4 0-10-20 16 120 6.3 0—10—10 21 104 5.8 EEBertilized plots 0-10-60 + s 181 312 11.8 o-1o—3o + s 97 323 11.8 0-10-20 + s 25 121 12.2 0-10-10 + s 14 238 10.6 0-10-60 214 134 12.5 0—10-30 84 130 11.5 o-10-2o 31 122 11.1 0-10-10 18 101 9.2 I *Soils sampled in May, 1956 **s = 500 pounds of NaCl applied per acre. 121 TABLE 23 THE AMOUNT OF WATER SOLUBLE POTASSIUM AND SODIUM IN GREEN SUGAR BEET TISSUE AS RELATED TO SOIL TREATMENT, 1955 Parts per million in tissue Salt only* Salt + F Residual F Treatment K Na K Na K Na K Na 0-10-60 4100 1940 4625 1930 4750 1320 5650 1235 O—lO—3O 2650 3540 3700 3410 2800 1830 3275 1380 O—10—2O 1575 3560 2750 3210 1975 1540 2850 1550 0—10-10 1375 2665 1600 4280 135O 1650 1650 1180 H *Salt only = 500 pounds since 1951. of NaCl applied per acre annually Salt + F = 500 pounds of NaCl plus 1000 pounds of designated fertilizer applied per acre since 1951. Residual No salt (NaCl) ever applied and no fertilizer applied since 1954. F = 1000 pounds of designated fertilizer applied per acre since 1951. 122' .mmmH .psmauwmnp Haom 0:0 manna» noon 00w50 :00uw no usoucoo sauce» 0H90p00huxm A090: 020 cooxuon manucoauaflop one .om ohswam . P202205 .__00 07010 00070 00.070 . 00-070 _ _ _ 4 _ L AI _ _ _ q _ L 14 _ _ Azum / mm~.....Em.../ I<\< artlllllllllulflulflldflllllll \\\\\\ 100m. , I (III? uuuuu ....\ ..<00.000\V \o\ \\ \ \ 10000 \ \ \ 005.: 00... + .002 / L. /v\\ \ \ all-IO. ' V‘\/ I I'IIIHI".IIO|IH.\\\ \\ /4|| \ .0 e2 1 Down 1000? HOSSIJ N338!) NI (de) 0N HTGVIOVHJXS 8317M 123 .mmmH .0900 000 0uaaau0 0L0: Aao0zv 0H00 mo 00::00 com 0:0 “H0020 ”H00 o: 090:: uuoaa 250000009 H050H00h 0:» 5000 00000 900n 00w50 no 0H0Hh 0:» 0:0 0500a» 9009 000:0 :0000 no 0:00:00 550000 0Hn0uo0puxo 00003 0:» :003909 aanmcoap0a0n 0:9 .Hm 0&5wam memE. zwwmw 2. Asia. 02 wqmdkodmhxm mwhdg Goon 00mm 000m 00.0w 000m 000. CON. 0 _ 0 _ _ _ m 1 : 07.070 1 m. l m. 0N-0T.0/l .1 t I m. OMIO~IO .. _N .. mm 003 me. .002 0 Q 02 .. mm QMZQQQ .002 00 002001 000 0 00-070 15 380V 83d SNOJ. 124 increased the yield of sugar beets in every case over those containing residual K only. Also, the amount of Na in the green petioles was highest from those plots receiving NaCl. The largest amount of K (5650 parts per million) was obtained in the tissue from the plots receiving 1000 pounds of 0—10-60 per acre; the least amount (1350 parts per million) was obtained in the tissue from the residual plots which had previously been fertilized with 1000 pounds of 0-10-10 per acre (Table 23). The decreasing order of magnitude of K contained in the green tissue within treatments was as follows: 0-10—60: F ) 0 > Salt + F 7' salt only 0—10—30: Salt + F > F > 0 > salt only 0—10—20: F ) Salt + F )- 0 > salt only 0—10—10: F ) Salt + F > salt only > 0 Where, salt only 500 pounds NaCl applied per acre. salt + F = 500 pounds NaCl plus 1000 pounds of the designated fertilizer. 0 = No NaCl or fertilizer applied (residual). F = 1000 pounds of the designated fertilizer applied per acre. These data show that the uptake of K by the plant was related to the amount of available soil K, and to the amount of K and Na applied. In every case, except one (0—10-10 treatment), the least amount of K was taken up by the plants from the plots which had received 500 pounds of NaCl only per acre. The lower uptake of K by these treatments, however, 125 'was compensated for by a larger uptake of Na (Table 23). A high degree of correlation was obtained between the K contained in the green sugar beet petioles and the yield of sugar beet roots, as shown in Figure 32. The following rela- tionships were significant at the l per cent level: (1) parts per million of K in the petioles versus the yield of sugar beet roots obtained from the residual plots, (2) parts per million of‘K in the petioles on the plots receiving K versus the yield of sugar beet roots, (3) parts per million of K in the petioles from the combined values obtained from the residual and fertilized plots versus their respective yield Ivalues. The respective correlation coefficients for these relationships were 0.623, 0.801, and 0.830. A curvilinear relationship was obtained where the K in the green tissue obtained from the plots receiving applied K was plotted against the yield obtained from the respective plots. The correlation coefficient for this relationship was 0.849, and significant at the l per cent level as shown in Figure 32. ~From this relationship the calculated maximum yield of sugar beets should occur when the beet petioles con- tain approximately 7000 parts per million of water soluble K. These data indicate the importance of tissue testing as a diagnostic tool in determining the K requirement of sugar beets. The relationships between extractable soil K on the unfertilized plots, extracted by 0.018 N CH3000H, and the K 6 m .mmmH ram »0sws< .0503» c0090 0:» no. »:0»:oo 5300969 0Hn0»o0.~»x0 0303 0:» 0:0 300.“ »00n .0090 no 303 0:» c0250: 3:0:030H0h 0:9 .mm 0.30:" mamm; zmmmo 2. Asia: v. mqmosmh x no monsoa on» can manna» poop hows» coohw no acoucoo Efiammdpoa cannuompuxo pond: on» coozuon nanchapmHon one memE. zmwmw 2. “Sun: v. m4m 0.018 N CH3000H + 0.03 N NaF (1:16) > 0.025 N HCl + 0.03 N NHNF (1:4) > 0.018 N ‘— CH3C00H + 0.03 N NaF. (1:14) > 0.018 N CH3COOH (1:14). EXPERIMENT IV: SODIUM—POTASSIUM INTERACTIONS Crop: Sugar Beets The effect of applications of Na, as NaCl, and K, as KCl, and the interactions of Na and K on the yield of sugar beets was studied. The soils were sampled and P, K, and Na determined by extracting the soil with 0.018 N CH3COOH. Green sugar beet tissue (petioles) was sampled in August, 1955 and water soluble Na and K determined. Total K, Na, and Mg were determined in the sugar beet tops and roots and 145 the yield, in tons per acre, determined. 1. Good yields of sugar beet roots were obtained where the residual soil P and K tests were approximately 27 and 300 pounds per acre, respectively, when supplemented with 500 pounds of NaCl per acre. 2. A sugar beet crop yielding 25.1 tons of roots and 15.9 tons of tops per acre removed 543 pounds of soil K per acre. 3. Sodium appeared to be effective in substituting for K at low levels of soil K. 4. An inverse relationship existed between the yield response of sugar beets to NaCl and increased levels of soil K. 5. Statistically significant correlations were obtained between soil K (0.018 N CH3COOH extractable), water extractable K in the green tissue, total K uptake and the yield of sugar beet roots. 6. The K contained in sugar beet tops was a better indicator of yield response to K than the K contained in the root tissue. 7. An inverse relationship existed between the per cent K and Na and K and Mg in sugar beet tops. 8. The maximum yield of sugar beets occurred where the beet petioles contained 7000 parts per million of water extractable K. 9. The extracting solution employing 0.018 N CH3COOH is a valuable tool in predicting yield response of sugar beets 146 to applied soil K. Also, the large loss of soil K, due to crop removal, indicates the need for annual soil tests to determine fertilization recommendations for sugar beets. IO. 11. LITERATURE CITED Aderikhin, P. G. 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