wwr— " -—-—_~——— ——‘—w THE EVALUAFEON 0F VAREGUS MAGNESEUM (EA-£355“ WHEN AWLEEDF Wfim MEX-ZED“ FERTEUZERS macaw gut {*Em Emma :35 M. 5. MECHEGM STHE UKEVERSETY Lawrence Alton Rudgers 1967 ——-— ————~< ~‘Iv — -_.—9“ ~— ‘ {THESIS nanny Mdngm Statc UII'NCI‘Sity ”mm—M - . FM? ms nu? r~, ' ' .2 1 'r " " 4; 25 um .u- kafi'sm ABSTRACT THE EVALUATION OF VARIOUS MAGNESIUM CARRIERS WHEN APPLIED WITH MIXED FERTILIZERS by Lawrence Alton Rudgers The interaction of six Mg carriers and two P sources was evaluated in a greenhouse study with oats and in three field experiments with potatoes. Yield of oat plants or po— tato tubers, plant content, and total uptake of Mg, Ca, and K, and available soil P, K, Ca, and Mg were determined. Calcined magnesite was more effective when coated on monocalcium phosphate (MCP) (initially acidic) than when coated on diammonium phosphate (DAP) (initially basic). The results for calcined brucite were more variable but followed the same trend. The P sources had no effect on the availa— bility of Mg from uncalcined magnesite and serpentine coated on the P fertilizers, or on MgSO4°7H20 mixed'with the P fertilizers. Sulfate of potash magnesia ("Sul-Po-Mag"), when dry blended with a fertilizer containing both MCP and DAP, was as effective as MgSO4'7H20. The order of availability of the Mg carriers when ap— plied with MCP was: calcined magnesitefigé calcined brucite > or —_= MgSO4-7H20 > uncalcined magnesite g serpentine, and Lawrence Alton Rudgers when applied with DAP the order was: MgSO -7H20 > or 4 :== calc1ned magne31te Qé:calc1ned bruc1te > uncalCined magne— . N , Site :2 serpentine. THE EVALUATION OF VARIOUS MAGNESIUM CARRIERS WHEN APPLIED WITH MIXED FERTILIZERS BY Lawrence Alton Rudgers A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Soil Science 1967 .\ k s .‘ ‘ 4““ v. M, ACKNOWLEDGMENTS The author wishes to express his sincere appreci— ation to Dr. B. G. Ellis for his assistance and encourage- ment throughout this study. The author also would like to thank Dr. E. C. Doll for his helpful suggestions during the earlier phases of this study. The writer is very_grateful to Dr. D. L. Thurlow, Donald Christenson, James Oaks and Larry Beard for their help with the field experiments. The author would also like to thank Mrs. Nellie Galuzzi for her assistance in the statistical analysis of the data. The writer wishes to acknowledge the financial as- sistance for this study provided by International Minerals and Chemical Corporation and the Tennessee Valley Authority. ii TABLE OF CONTENTS INTRODUCTION LITERATURE REVIEW Magnesium in Plants Function of Magnesium in Plants Principles of Foliar Analysis Content of Magnesium and Other Nutrients in the Plant Magnesium in Soil Potassium-Magnesium Antagonism Calcium—Magnesium Antagonism Calcium—Magnesium—Potassium Antagonism in Terms of Soil Cation Exchange Equilibria and Cationic Fixation by Clays Sources of Fertilizer Magnesium MATERIALS AND METHODS Locations of the Field Experiments Treatments in the Field and Greenhouse Methods of Preparation and Properties of the Treatment Fertilizers Experimental Design and Cultural Practices in the Field Experimental Design and Cultural Practices in the Greenhouse Yield Determinations in the Field Laboratory Analyses Soil Tests Fertilizers Analyses Plant Analyses RESULTS AND DISCUSSION Soil Test Results Fertilizer Analyses Greenhouse Studies Field Studies Comparison of the Mg, Ca and K Contents of the Oat and Potato Plants iii Page 15 16 20 20 24 27 28 29 31 31 31 32 33 34 34 36 39 49 64 Page Simple Correlations Between Potato Yield or Mg Content and Available Soil Nutrient Levels 68 Multiple Correlations Between Yield or Plant Mg Content and Plant and Soil Nutrient Content 69 GENERAL DISCUSSION AND SUMMARY . . . . . . . . . . . . 7O BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . 72 APPENDIX . . . . . . . . . . . . . . . . . . . . . . . 83 Descriptions of the Soil Series at the Three Field Locations 84 Tables of Data 88 iv Table 10. 1A. 2A. LIST OF TABLES Climatological information for United States Weather Bureau stations near each of the field experiments Summary of treatments in the field and in the greenhouse Average pH and available P, K, Ca and Mg per acre for the three soils in the field and the soil in the greenhouse Analyses of the experimental fertilizers Results for analyses of varianCe of data ,from the greenhouse experiment Summary of field data for all three locations . . . . . . . . . Results for analyses of variance of data from the field experiment in Otsego County Results for analyses of variance of data from the field experiment in Houghton County . . Results for analyses of variance of data from the field experiment in Montcalm County Simple correlation.analysis; dry weight and nutrient content of first crop of oats in the greenhouse Data from the greenhouse experiment; first crop of oats Data from the greenhouse experiment; second crop of oats . . Page 22 25 35 37 44 50 59 62 67 88 9O Table 3A. 4A. 5A. 6A. 7A. 8A. 9A. 10A. 11A. 12A. 13A. 14A. 15A. Data for potatoes in the field; Otsego County Data for potatoes in the field; Houghton County Data for potatoes in the field; Montcalm County Data for potatoes in the field; Montcalm County, Simple correlation analysis; yield and nutrient content of oats in the greenhouse Simple correlation analysis; nutrient content of potato Otsego County Simple correlation analysis; content of potato petioles results; Otsego County Simple correlation analysis; nutrient content of potato Houghton County Simple correlation analysis; content of potato petioles results; Houghton County Simple correlation analysis; nutrient content of potato Montcalm County Simple correlation analysis; content of potato petioles ,results; Montcalm County Simple correlation analysis; yield and nutrient content Montcalm County Simple correlation analysis; nutrient content of potato vines dry weight of second crop yield and petioles; yield, nutrient and soil test yield and petioles; yield, nutrient and soil test yield and petioles; yield, nutrient and soil test dry weight of potato vines; dry weight yield and nutrient content of potato vines and soil test results; Montcalm County vi Page 92 94 96 98 100 101 102 103 104 l05__ 107 108 LIST OF FIGURES Figure Page 1. Map of Michigan showing location of field experiments and weather stations . . . . . . 21 2. Yield of oat plants as a function of rate and carrier of Mg and carrier of P——first crOp . . . . . . . . . . . . . . . . . . . . 4O 3. Mg content of oat plants as a function of rate and carrier of Mg and carrier of Ph- first crop . . . . . . . . . . . . . . . . . 41 4. Uptake of Mg as a function of rate and carrier of Mg and carrier of Ph-first crOp . 42 5. Yield of oat plants as a function of rate and carrier of Mg and carrier of P—-second crop . . . . . . . . . . . . . . . . . . . . 46 6. Mg content of oat plants as a function of rate and carrier of Mg and carrier of Ph- second crop . . . . . . . . . . . . . . . . 47 7. Uptake of Mg as a function of rate and carrier of Mg and carrier of P—-second crOp . . . . . . . . . . . . . . . . . . . . 48 8. Mg content of potato petioles, July 22, 1965 (9 weeks after planting) as~a function of rate and carrier of Mg and carrier of Ph— Otsego County . . . . . . . . . . . . . . . 55 9. Mg content of potato petioles, August 16, 1965 (12 weeks after planting) as a function of rate and carrier of Mg and carrier Pb—Otsego County . . . . . . . . . . 56 10. Yield of tubers as a function of rate and carrier of Mg and carrier of Ph-Houghton County . . . . . . . . . . . . . . . . . . . 58 vii Figure Page 11. Mg content of potato petioles, August 8, 1965 (10 weeks after planting) as a function of rate and carrier of Mg and carrier of Pb-Houghton County . . . . . . . 6O 12. Mg content of potato petioles, July 5, 1965 (9% weeks after planting) as a function of rate and carrier of Mg and carrier of Pb— Montcalm County . . . . . . . . . . . . . . 63 13. Mg content of potato vines as a function of rate and carrier of Mg and carrier of P—— Montcalm County . . . . . . . . . . . . . . 65 viii INTRODUCTION The world population is expanding at an exponential rate. The burden of producing adequate quantity and quality of food for this expanding population is shared by agri— cultural specialists, including those in soil fertility and fertilizer research. By applying new technology, such as the increased use of fertilizers, agriculturalists have in— creased yields and improved crop quality. But, only in certain countries have they been able to keep pace with the population explosion. And, the situation promises to worsen unless the rate of development of new technological methods increases. Higher yields produced because of new improved methods and technology may increase the need for elements that were formerly in sufficient supply in soils. For ex- ample, Mg ranks seventh in abundance in the earth's crust; consequently, in the past, most soils contained adequate levels of Mg. Now, however, Mg deficiencies are commonly found on many acid, sandy soils. This necessitates a criti- cal evaluation of sources of fertilizer Mg that may prove to be economical. The objective of this investigation was to evaluate the effectiveness of various carriers of Mg when coated on granules of mixed fertilizer made with either monocalcium phosphate (initially acidic) or diammonium phosphate (in— itially basic) as a source of P. LITERATURE REVIEW Loew(59), in 1892, was probably the first person to realize that magnesium (Mg) is important in plant growth. But, he and many other early workers were more concerned with Mg as a toxic element rather than an essential nutrient (25, 29,52,58,59,60,62). Loew believed that an excess of either lime or magnesia is toxic to plants and that either substance will neutralize the deleterious effects of the other. Thus, a favorable lime-magnesia ratio must be established in both the soil and in the plant (58). However, it is now known that Mg or calcium (Ca) toxicity as described in the early literature was potassium (K) deficiency. _Loew also introduced the hypothesis that Mg acts as a carrier of phosphorus (P) in the plant (59,61,111). Until recently, much of the research in Mg plant nutrition was designed to test this hypothesis. Until the past 10 years, Mg was seldom found to be deficient. As late as 1963, Tobin and Lawton (109,110), re— ported that in Michigan with 14 crops grown on 37 soil types from 1956 to 1958, there was little or no yield response to applications of Mg. New, however, Mg deficiency symptoms are commonly found in potatoes, oats, and rye grown on loamy sands or sandy loams in Michigan (22). Magnesium deficiencies are also prevalent in various vegetable crops grown on the sandy soils of the Atlantic Coastal Plain (12,13). Because higher rates of more refined, higher analysis fertilizer are resulting in higher yields, greater amounts of Mg are being removed from the soil. Consequently, some soils which con— tained adequate levels of Mg are now deficient (41,63). As a result, more research is now being devoted to the development of economical sources of fertilizer Mg. Magnesium in Plants Function of Magnesium in Plants Magnesium is present in the plant in at least three forms. It is present in combined form in the protoplasm, comprises 2.7 percent of the chlorophyll molecules and oc— curs as an inorganic salt in the cell sap (18,103,125). Since Mg is the only mineral in the chlorophyll molecule, it is not surprising that the most obvious Mg deficiency symptom is chlorosis. Since Mg is mobile in the plant, chlorosis first appears on the lower leaves. Yellowing first occurs as patches between the veins and around the leaf edges. The younger leaves at the top of the plant then begin to curl. Later, the yellow areas become necrotic and the tissue may eventually disintegrate leaving holes in the leaf. The veins then appear as prominent green areas (18,22,103,125). Magnesium plays a predominant role in the activity of various enzymes concerned with carbohydrate metabolism. It serves as an activator for at least 14 enzymes which catalyze those reactions involving transfer of phosphate groups. Below is an example of a reaction for which the metal activator is Mg (103). ++ . 0 fig A Glucose + AdenOSine Triphosphate Glucokinase’ Glucose-6—Phosphate + Adenosine DiphOSphate It is known that Mg functions in photosynthesis, but the exact mode of action is not Well understood. It also is probably involved in protein synthesis, since it is found in ribosome organelles which are specific sites for protein synthesis. It is thought that Mg+2 ions hold together mole— cules of ribonucleic acid (RNA) by combining with the phos- phate radicals of RNA (103). Because both Mg and P accumulate in the seed, it was postulated 60 years ago by Loew (55) that Mg serves as a carrier for phosphoric acid (H P04) in the plant. Most 3 workers in this area believed that Mg acts as a carrier of P by forming Mg-phosphates which are more soluble than Ca- phosphates. Calcium phosphates may precipitate in plants which contain a much higher concentration of Ca than Mg, thus slowing the translocation of P (5,20). As mentioned earlier, much Mg research has been designed to refute or sub— stantiate this theory. Some early workers (35,49,79,81,108) found that many crops responded to P fertilization only when Mg was also applied. They maintained that this was sufficient evidence in support of the theory. However, other researchers (28) reported that the influence of Mg on the effect of P in- creasing yields was small. They were not convinced that Mg is a carrier of P. Many workers (3,6,21,35,53,98,1l4,121) obtained posi- tive correlations between content of Mg and P in the whole plant and thought that this was strong evidence in support of the theory. But, just as many researchers (27,36,39,43, 44,77,87,115,122) were unable to obtain positive correlations. In recent years, Truog (111) and webb (118) have postulated that by comparing the Mg and P contents of the vegetative and reproductive organs, they can distinguish be— tween the effect of Mg upon the absorption and its effect upon the translocation of P in plants. WOrking with soybeans in nutrient solution, Webb (118) found that although the con— tent of P in a whole plant was not increased by greater Mg uptake, the translocation of P from the vegetative portions to the seed was increased. Therefore, although Mg may not enhance the absorption of P, it may aid in the translocation of P'by acting as a carrier. Recently,some plant physiologists (103) have been theorizing that the role of Mg as a carrier is due to the great importance of this element as an activator in many of the enzyme systems involved in P metabolism. It is thought that the response'to P might be limited, if the enzymatic systems involved in its metabolism are limited by the supply of Mg. If the Mg supply to a particular portion of the plant were to increase, the need for P would increase and P would move to this site. Principles of Foliar Analysis When researchers first began analyzing plants for nutrient content, they analyzed the plant as a unit. There are, however, certain disadvantages to this technique. Ac- cording to Thomas (105» a gross analysis of heterogeneous organs, all having different sensitive functions, does not give a "sufficiently comparative index in reflecting the re— sponses of the plant to differences in its environment." The ideal plant sampling would consist of leaves of the same metabolic age (taken from the same position on the plant) taken at the same time from a sufficient number of plants in each plot. In order to provide a sample representative of a 4—row plot the leaves should be selected from the center two rows (105,112). In addition, ideally, the experiment should be conducted in a homogeneous growing medium and there should be several sampling dates. At each sampling date, leaves of the same age as were taken in the previous samplings should be selected (105,112). If this procedure is followed, the effects of the environment (such as varying fertilizer rates), and not effects due to senescence or differing plant parts, will be reflected in the nutrient content of the leaves (105, 112). It is true that foliar analyses can not be used to ob- tain total nutrient uptake data. In such cases, it is neces— sary to base the analyses on whole plants. But, when a com- parative study on the effects of varying fertilizer rates or sources throughout the growing season is desired, foliar analysis is the more sensitive method. When conducting foliar analysis of potatoes, Tyler and Lorenz (112) and others (101) recommend taking 40 to 50 petioles from the fourth leaf below the growing tip of the plant (usually the youngest fully expanded leaf on the plant) in the center two rows of a 4-row plot. The first sampling should not be taken before three to four weeks after emergence. Content of Magnesium and Other Nutrients in the Plant It is generally agreed that as the supply of avail- able Mg in the growing medium increases, the content of Mg in the plant increases (7,8,21,31,54,57,71,72,83,84,90,94,95, 98,99,101,106,114). However, plant species differ in their ability to absorb Mg and other plant nutrients (8,17,110, 125). Legumes, for example, have larger Ca requirements and can more easily remove Ca from the soil than grass and cereal crops (17). Cucumbers and potatoes have higher Mg requirements than oats and barley (110). This is reflected in the content of Mg in these crops. Tobin and Lawton (109, 110) on a sandy soil in Michigan found that oats and barley had an average Mg content of 0.16 percent, whereas, the con— tent of potatoes was 0.40 percent. There are several explanations for plant species differing in their abilities to absorb cations. One theory is that plants which require large amounts of cations, pro- duce more carbon dioxide (or carbonic acid). The hydrogen ions produced can then move onto the exchange complex freeing cations ,for uptake by the plants. Another theory is that plants which have a higher root cation exchange capacity are better able to absorb cations. As of yet, it is not known whether either of these theories is valid (17). Using leaf chambers and a carbon dioxide infrared gas analyzer, Peasler and Moss (82) have found that the critical level of K in maize leaves is 2 milligrams per gram on a fresh weight basis and for Mg, 200 micrograms per gram. Normal appearing, but K stressed leaves, showed a reduction in photosynthesis, but Mg affected photosynthesis only after chlorosis appeared. .They theorize that in the case of Mg, the reduction in the photosynthetic rate is due to a break- down of chlorophyll, whereas K deficiency causes a decrease in the net assimilation rate by decreasing the stomatal aperatures. For most crops, the total content of Mg, Ca and K when expressed in milliequivalents per 100 grams of oven dry whole plant material remains rather constant (4,64,113). This is known as Ehrenberg's potash-lime law, because he 10 first saw a relationship between Ca and K in plants (25,64). Usually the relative intensity of removal of cations from the soil is K+l‘>Ca+2 > Mg+2 (19,125). Even though the relative content of these cations in the plant varies, the total con— tent of cations must remain rather constant in order to buffer cell sap, neutralize organic acids and regulate salt concentration (64). _Also, because many of the prOperties and functions of Kfl, Ca+2 and Mg+2 are not interchangeable, the relative content of these cations in the plant should not greatly deviate from a theoretical balance (64). It follows that in order to obtain the correct amount and balance of K71, Ca+2, and Mg+2 in the plant, the soil in which the plant grows must also have the proper 1 +2 balance and adequate levels of available KI , Ca and Mg+2. Magnesium in Soil Magnesium occurs in the soil in primary and secondary minerals such as micas, chlorites, and vermiculites, from which Mg is released slowly to the exchange complex and into the soil solution where it is available for plants (18,88). In humid regions, the most abundant basic cations are Ca+2 and Mg+2. As a soil is leached, the percent base saturation decreases and the percent hydrogen ion saturation (or aluminum complexes) increases along with a reduction in soil pH (18, 22). As a consequence, acid sandy soils with low cation 11 exchange capacities are often deficient in Mg and Ca (9,12, 13,15,16,l7,18,21,22,50,57,66,72,76,83,84,90,96,102,108,124). Although the figures do not agree exactly, most workers sug— gest that if the Mg saturation on the exchange complex falls below 10 percent and/or when the level of available Mg falls below 75 pounds of elemental Mg per acre furrow slice (2,000,000 pounds per acre), Mg will be deficient (5,22,31, 50,71,90,96,98,100,102). However, it is actually more difficult to predict when Mg will become deficient than is implied in the pre- ceding paragraph. The problem is often one of obtaining good correlations between Mg soil test results,and crop yields. This difficulty stems at least in part from the variation among soils in the types and relative amounts of different silicate clays present. The silicate clays differ in their abilities to fix and release Mg. Caillere, Menin and Mering (11) and Grim (32) indicate that Mg+2 can be fixed as mag— nesium hydroxide (Mg(OH)2) in the interlayer spaces of mont— morillonite, resulting in a chlorite type structure. Mag- nesium ions can also be fixed by "degraded chlorite" in a . . +1 manner Similar to K fixation by ”degraded illite" (32). Magnesium ions are apparently very readily fixed by vermicu- lite (ll). Vermiculite is composed of silicate layers bound together by Mg+2 and Ca+2 which are probably exchangeable. Potassium and ammonium (NH4+1) ions are capable of collapsing this mineral and preventing expansion upon hydration (ll). 12 Thus, after K addition,the Mg+2 and Ca+2 are no longer as readily available to plants. Kaolinite, on the other hand, does not fix Mg. In soil testing laboratories, 1_N ammonium acetate (NH4Ac) is often used as the extracting solution for esti— mating available Mg. If a soil is high in vermiculite, the high concentration of NH4+ in the extracting solution can collapse the clay trapping Mg+2 and giving an available Mg estimate which is lower than the amount of Mg available to plants in the field. To a lesser extent this probably can happen for soils which contain "degraded chlorite" and mont— morillonite (11). This may partly explain why some soils testing low in Mg will not respond to Mg fertilization. Al- though there is not complete agreement, many researchers indicate that the Mg in the brucite layer of chlorite type clays is easily released and available to plants (41). But, the NH4Ac extracting solution will not remove this Mg (41). This may also help explain why there is often poor corre- lation between Mg soil test results and crop yields. Thus, it becomes apparent that when estimating avail— able Mg, the types and relative amounts of clay in the soil must be considered. An unbalanced soil nutrient status can also lead to a Mg deficiency. For example, if calcic limestone is ap— plied to=a"very.acid soil, the ratio of Ca to Mg and K be— come so great that a deficiency in these elements results. 13 Or, excessive applications of K may result in a high ratio of K to Mg and subsequently, a deficiency in Mg (17,18,22,40). Because the subject of cationic balance has received so much attention over the past 60 years, it will be discussed here in more detail. Potassium-Magnesium Antagonism Numerous researchers, working with water, sand, and especially soil cultures, have found that if K is applied in excess and/or the ratio of K to Mg on the exchange complex is above 4 to 1, then Mg deficiency often develops (13,17,22, 23,33,42,46,48,51,64,73,74,75,83,84,86,9l,92,93,104,107,113, 116,117,119). Although this usually occurs in acid sandy soils low in Mg, Mg deficiency symptoms sometimes develop on soils which have abundant available Mg, but, which have ex— cessive amounts of exchangeable K (42). Hovland (42) reports that Mg deficiencies developed in potatoes and sugar beets grown on soils of calcareous lacustrine origin with ample Mg, when K was applied at a rate of only 100 pounds elemental K per acre. Unless sufficient Mg is available, crops with high Mg requirements may not respond well to K fertilization. In water and sand cultures high KéMg ratios do not induce Mg deficiencies as easily as in soil cultures. This may indicate that the center of the KkMg antagonism is on the soil exchange complex, rather than the plant roots (17, 52). 14 CalciumrMagnesium Antagonism Around the turn of the century, Loew and others (58, 59,60,62) developed the famous lime—magnesia ratio hypothe— sis. They hypothesized that excesses of either lime or mag- nesia are toxic to plants and that either substance will neutralize wholly or in part the deleterious effects of the other. They stated that each crop requires a rather definite ratio of Ca to Mg in the soil. For oats this was placed at a 1 to 1 ratio of CaO to MgO, for barley 2 to l, and for buckwheat 3 to 1. But, other researchers (29,58,80) criti- cized this hypothesis, stating that the ratios can vary con— siderably more than Loew allowed. They also suggested that many of the favorable effects which follow the adjustment of the ratio "can easily be explained on many other grounds which do not call at all for the introduction of the hypothe- sis of the lime-magnesia ratio" (58). It is probably true that a crop does not require a rigid lime-magnesia ratio, but Loew was correct in postu— lating that an antagonism exists between Ca and Mg. Many re- searchers (13,25,64,66,67,69,76,89,106) have since reported this phenomenom for a variety of crops on many different soils. 15 Calcium-Magnesium—Potassium Antagonism in Terms ofTSoil Cation Exchange Equilibria and Cationic Fixation byAClays As mentioned before, the fact that many of these an— tagonisms are not easily produced in water and sand cultures, indicates that the interactions between Ca, Mg and K are con— trolled largely by cation exchange equilibria. If (K+lad.) +2 1 2 ad.) are the activities respectively of KI and Mg+ 2 and (Mg on the exchange complex, and (Kflsol.) and (Mg+ sol.) are the activities of these ions in solution, then the following equilibrium and mass action expression can be formulated (l7). 2K+lsol. + Mg+2ad. : 2K+lad. + Mg+zsol. _ (Kflad.)3 Mg+zsol.) K ‘ +1 . . +2 (K sol.) (Mg ad.) When an excess of K is added to the soil, the activi- ty of K+1 in the soil solution (Kflsol.) is increased and the equilibrium disturbed. In an attempt to reestablish the equilibrium, the reaction moves to the right with KI re— placing Mg+2 on the exchange complex. This increases the activity of Mg+2 in solution (Mg+2sol.) and therefore, in— itially, its availability to plants. However,later, much of the Mg++ and KT in solution is leached from the soil. The reaction continues to move closer to equilibrium, but the equilibrium activity of Mg+2 on the exchange complex 2 (Mg+ ad.) will be lower than it was before the K was added to the soil. As the reaction moves toward equilibrium, the l6 2sol.) decreases and approaches equality with the 2 . + (Mg +2 $01.), and therefore the (Mg ad.). Consequently, the (Mg+ availability of Mg to plants, will be lower than they were before K was applied to the soil. As mentioned earlier, montmorillonite "degraded illite" and especially vermiculite can fix Mg (11,30,32). Since Kfl ions bring about the collapse of these clays and trap Mg and Ca between the silicate layers, it can be seen that excesses of K in a soil could enhance this fixation and decrease the supply of available Ca and Mg. Sources of Fertilizer Magnesium Dolomite (CaCO 'MgCO3): Dolomite and limestone 3 which contains dolomite (dolomitic limestone) are, when com- pared to the other fertilizer sources of Mg, moderately solu- ble (l4,41,65,120). Since they are more soluble in acid soils (30) and can be used to raise soil pH, they are often applied to these soils in order to gradually build up the supply of available Mg. Magnesite (MgCO3): Magnesite is also a moderately soluble form of fertilizer magnesium. Some researchers sug— gest that magnesite and dolomite are equally available to plants (63,134). Others (65) state that magnesite is more available than dolomite, while still others (41,63) suggest that it is less available. However, since the differences in their availabilities are so small, it can be safely 17 stated that plants fertilized with these minerals can utilize about the same amount of Mg from each. Brucite (Mg(OH)2): Brucite contains principally Mg- hydroxide (Mg(OH)2). The mineral consists of two sheets of hydroxyl groups arranged in a hexagonal closely packed structure with Mg++ between the sheets (10,38,123). Mg(OH)2 is more soluble than MgO. However, in brucitetflmsMg+2 and OH- ions are organized in a crystal lattice structure. Consequently, the solubility of brucite may be less than pre- cipitated Mg(OH)2 and Mgo. Serpentine (3MgO-ZSi02-2H20): Serpentine is a greenish silicate mineral which has 814011—6 groups arranged in chains. These chains are held together by Mg(OH)2 groups. But, because these bonds are weaker than the silicon (Si+4) to oxygen (0.2) bonds, the mineral is usually fibrous. It is commonly a constituent of asbestos. Because serpentine is a silicate, it is one of the more insoluble fertilizer sources of Mg (10,38,120,l23). During the first 2 years after appli- cation, it is often less available than dolomite. However, by the third year it probably supplies as much Mg as does dolomite (16). Since it is more expensive than dolomitic limestone, and does not have as much neutralizing power, it is not usually applied to acid soils to gradually build up the supply of available Mg. However, it is occasionally mixed with supersphosphate and 15 percent water, then allowed to cure for 2 to 3 weeks. In this way the superphosphate be— comes less acidic and the Mg is placed in a more available 18 form. The resulting serpentine-superphosphate has a better consistency and is easier to handle than superphosphate (l, 2,26,37,68,78). Olivine (Mg,Fe)ZSiO Olivine is also a greenish 4: silicate mineral, but has iron (Fe) substituting for Mg in the crystal lattice. Its structure also differs from serpen— tine in that it contains separate SiO4 groups which are not 2 ions are shared by Mg+2 and Si+4. arranged in chains. The 0- As a consequence, olivine is often granular and massive (10, 38,123). However, it has about the same solubility as serpentine (97,120) and is sometimes mixed with superphos- phate (24,37,56,68,107). _Epsom Salts (MgSO4°7H20): Epsom salts is one of the most soluble forms of fertilizer Mg commonly used. It is ap- plied to correct a severe Mg deficiency during the year of application. It is often applied to less acidic soils that do not require liming. Dolomitic limestone would not re— lease Mg rapidly enough on less acidic soils (10,22,38,123). Sulfate of Potash Magnesia (Sul-Po—Mag) (KZSO °2MgSO4): This is a double salt of K and Mg and is 4 probably as effective in correcting Mg deficiencies as MgSO4'7H20. It is also used to quickly correct Mg deficien— cies (14,15,22). In addition to the fertilizer sources listed, dolo— mite, brucite, magnesite, serpentine and olivine are often calcined, heated at temperatures ranging from 6000C to 19 llOOOC. This converts the Mg from more insoluble forms to MgO, which increases the availability of Mg (34,68,120). Below are listed some of the fertilizer sources of Mg in a probable order of decreasing ability to supply Mg to plants: A/ . Epsom Salts=== Sul-Po-Mag > MgO > calCined bruciteESE’calcined dolomite=== calcined serpentine 2:: calcined olivineE== calcined magnesite > brucite > dolomite€;; magnesite > serpentine 2; olivine > hornblend ”—3; talc. MATERIALS AND METHODS Locations of the Field Experiments Three field experiments with potatoes as the test crop were conducted at the following locations in Michigan where Mg deficiency had been identified (see Figure 1):‘ l. Otsego County - on the Edwin Estelle Farm in the S.W. one quarter of section 6 in T.30N. and R.4W. .Houghton County - on the Paul Mustonen Farm in the S.E. one quarter of section 24 in T.53N. and R.34W. Montcalm County - on the Arville Perkins Farm in the S.W. one quarter of section 12 in T.lON. and R.5W. Climatological and weather information for United States Weather Bureau stations located near each of the three field experiments is summarized in Table 1. Because of vari— ation in elevation and distance to Lake Michigan between the weather stations and the Edwin Estelle farm, the average length of the growing season at this location could only be 'roughly estimated at 60 to 90 days. The climatological data shows that precipitation for the 1965 growing season was be- low normal at all three locations. Brief descriptions of the soil series for the three field locations are given below. More detailed descriptions are given in the Appendix. 20 21 Figure 1. Map of Michigan showing location of field experi- ments and weather stations. met U.S. Weather Station ocation 2, Houghton County ault Ste. Marie Jordan , U 1 . Ju-Yanderbil Trout U.S. 0 ' _ Woottion' 1 Weather Sta on L___§tsego C0: ty Station F""‘1 ' L] ‘. cation 3 Montcalm Co nty .QGreenville . U.S. Weather Station Lansing Det o t L___L__J O 20 '40 Miles 22 omH mm on me 5 mm 0 am ma .um 5mm .um own .coaum>mamv .coflpm>mamv cmmflsoflz musnoo .mHHH>cme0 Eamousoz oma ma mo 0% 0 am OH mm ma A.um Hema A.um oom .coaum>mamv .coapm>mamv cmmflnoflz hucsoo .umESHmO sossmsom om Hm mo me mam Hm m.m am am A.um mmm .sofium>mamv smmfizoflz .coflumum “some uaflnuwpum> oma em no me m om 0 mm ma A.um omm A.um oawa mcoflum>wamv .GOHum>mev smmflnoaz mucdoo .cmGMOU ummm omwmuo Hamm CH .Hmz .msfl Hmmw .ms¢ Hmww .ms¢ “mow Amwaflzv soaumpm ucmefluwmxm umnam cam I.oma Imago Imago Imago coaumum Hwnummz mo mcflumm Ca Monummz coflumooq ousumnmmswa Amococflv Ammnocflv Ucm meanmonm Ammmalommav moma Ammmalommav usmEHHmmxm ummq :003p Aomv monsumummEmB CH coaump soflumufimfio cmmBuwm Imm mama mo smmz Iflmflooum Jenn awe: mosmuman Honfidz cmmz mo some Hams mcoflpmum smwnsm Hmnummz mopmum Umuflsb MOM COHDmEHOMGH HMUHmoHoumEHHU .mucoaflummxw paofim may .H magma 23 l. Karlin series (Otsego County): The Karlin soils are well—drained, slightly to medium acid Podzols which have developed in loamy fine sand to fine sandy loam, 15 to 42 inches thick, overlying sand. Because they are sandy with low cation exchange capacities and have developed from acid parent materials, these soils are often deficient in Ca and Mg. 2. Mancelona series (Montcalm County): The Mancelona soils are well to moderately well drained, slightly to medium acid Podzols which have developed in either stratified gravelly and sandy outwash or in unas- sorted gravelly sand or loamy sand. Because these soils have better developed textural B horizons than the Karlin soils, they have higher cation exchange capacities. Also, since the parent materials for the Mancelona soils were more calcareous than those for the Karlin soils, they are probably less apt to become deficient in Ca and Mg. 3. Munising series (Houghton County): The Munising soils are well drained Podzols with fragipans, which have developed in strongly acid, reddish sandy loam glacial till derived from red sandstone. Because they have developed in strongly acid parent material, they are probably more often deficient in Ca and Mg than soils in the other two series. The topography of the plot areas in Otsego and Montcalm Counties was nearly level. But, the plot area in 24 Houghton County was rolling containing some ridges that were nearly 10 feet in height. Treatments in the Field and Greenhouse In Table 2 are listed the 20 treatments which were used in both the field and in the greenhouse. Four carriers of Mg, calcined brucite, calcined magnesite, uncalcined magnesite and serpentine were coated on the granules of two sources of P, monocalcium phosphate (MCP), and a mixture of diammonium phosphate and superphosphate (DAP). These made up treatments one through four and six through nine, respective— ly. Treatments five and ten served as checks,.With MCP and DAP, respectively, being used alone. Two sources of P were evaluated, because it was expected that calcined brucite and calcined magnesite, which both contain large amounts of MgO, would be more soluble in the acidic solution diffusing from dissolving MCP than in the more basic solution around dis- solving DAP. The P in most'wet-mixed fertilizers sold in Michigan is supplied as MCP, but that in the‘dry-mixed, or bulk—blended fertiliZers is largely DAP. Since sulfate of potash magnesia (KZSO4'2MgSO4) is a common source of fertilizer Mg, marketed as Sul—Po-Mag, treatment 11 was designed to test the effectiveness of a fertilizer formulated in the same manner as Sul-Po-Mag. Treatment 12 was included to serve as a check for treatment 11. 25 o «.mH o.em m.e men 0 In: 6202 OH oo.m a ma 6 mm m.e men om 0mmm.moAmm.omsm solmcflpcweumm m oo.m m as o.em m.v mce om moomz soumuammcmmz m pmcHUHMUCD oo.m m as o.em o.e men om om: soumuflmmcmms a emcaoamo oo.m m as o.¢m m.e m.vomms smImuHmm semen ma men 0H o~m5.eommz smImuHmm gowns mg no: ow o~m5.eomms smImuHmm acmmm mg no: om ONmB.eomms smImuHmm semmm ms nu: om o~m5.eommz smImuHmm acmmm ea mos OH omms.¢ommz smImuHmm acmmm mH 0 «.ma o.em m.¢ mas 0 III ocoz NH em.m m.ma m.mm m.¢ men om eommzm.eommu eoImammcmms HA ammuom mo mummasm 27 Mg response curves were constructed for Mg at rates of O, 10, 20, 30, and 40 pounds per acre with treatments 5 and 13 through 16 having MCP as the P carrier and treatments 10 and 17 through 20 having DAP as the P carrier. Methodsof Preparation and Properties of the Treatment Fertilizers The P carrier containing primarily MCP Ca(H2po4)2 was commercial granular 6—24—24. The superphosphate and triple superphosphate in this fertilizer were prepared by acidu— lating rock phosphate with sulfuric acid (H2804) and phos— phoric acid (H3PO4), respectively. These two fertilizers were then mixed with KCl and (NH then ammoniated and 4’2504’ granulated. Granulated DAP ((NH HPO4)_was prepared by 4)2 ammoniating H3PO4 by the Dorr Slurry process. This DAP was mixed with red granular KCl and granular triple superphos— phate in about a 1:1:1 weight ratio. The calcined brucite (MgO) was prepared by calcin— ation of brucite limestone at about 2100°F followed by hy— dration of the lime.to a fine powder which was removed from the unchanged magnesia granules by air separation. The cal- cined magnesite (MgO) consisted of the reactive grade of synthetic MgO. The uncalcined magnesite was weathered flue dust recovered from the precipitators in the caustic calci- nation of natural carbonate rock to produce calcined magne- site (MgO). The serpentine was serpentine rock that had been 28 crushed, dried, and screened. The Mg content of these carriers were 40, 56, 27, and 22 percent, respectively. The two granular base fertilizer materials were dry blended with the powdered Mg sources for one minute in an en— closed mixer. Then warm (lOOO-lZOOF) "used" motor oil was sprayed into the rotating mixer and mixing continued for another two minutes. In preparing the fertilizer for treatment 11, mag- nesium potassium sulfate (KZSO4°2MgSO4) (11 percent Mg) was dry—blended with granular potassium chloride, DAP and granular triple superphosphate. The fertilizer for check treatment 12 1 contained K SO SO 4. 2 4 '2MgSO in the place of K 2 4 Experimental Design and Cultural Practices in the Field In the field, the 20 treatments were replicated four times in a randomized block design. In Montcalm and Houghton Counties, each of the 80 plots was 50 feet by 11-1/3 feet (four (34 inch) rows). In Otsego County, the plot size was 50 feet by 8% feet (three (34 inch) rows). In Montcalm and Houghton Counties, 100 pounds of N per acre as ammonium sul- fate ((NH4)ZSO4), and 500 pounds of K per acre as KCl were plowed down before planting. In Houghton County these ferti- lizers were spread on the soil surface after planting. 1The treatment-fertilizers were prepared by the Di- vision of Chemical Development, Tennessee Valley Authority, Muscle Shoals, Alabama. 29 Sebago potatoes were planted on May 15th in Montcalm County, May 22nd in Otsego County and May 3lst in Houghton County. A two-row planter spaced the seed potatoes 11 to 14 inches apart in the row at a depth of about six inches. The fertilizer was placed in two bands on either side of the row about two inches below the seed and two inches to the side. A rotating solid cone mounted on the planter above each row was geared to make one rotation in 50 feet, so as to deliver a preweighed quantity of fertilizer uniformly along the row. The fertilizer was placed in a cylindrical bottomless con— tainer positioned over the apex of the cone. When the cylinder was lifted, the fertilizer flowed evenly down the surface of the cone into a circular trough, attached to the base of the cone, where it was scraped off into a hose lead- ing to the potato row. Throughout the growing season, hilling, cultivation, other weed control measures, insect control and disease con- trol were carried out by the cooperating farmers. In Otsego County the potatoes suffered moderate damage from a potato bug infestation. The severity of the damage varied con— siderably among the plots. The potatoes in Montcalm County were irrigated. Experimental Design and Cultural Practices in the Greenhouse In the greenhouse, the 20 treatments were replicated 6 times in a randomized block design with pots periodically rotated by one replication. 30 The soil used in the greenhouse was Karlin loamy sand obtained from.the Edwin Estelle Farm. The air dried soil was thoroughly mixed and then sieved to remove all stones above approximately eight millimeters in diameter. At that time a soil sample was taken to be analyzed at the Michigan State University Soil Testing Laboratory. Three thousand, five hundred grams of soil was placed in a number 10 can lined with a plastic bag. Enough (NH4)ZSO4 and KCl to provide 100 pounds of N and 500 pounds of K per 2,000,000 pounds of air dried soil (acre furrow slice) were thoroughly mixed with the soil. Nitrogen as (NH4)ZSO4 was added as needed during the growing season. The treatment fertilizer was placed in a circular band three inches in diameter at a depth of about 1% inches. Twenty oat seeds were planted July 19-20, 1965 at a depth of about % inch in a four inch diameter circular band. After emergence the oats were thinned to 15 plants per pot. When the oats needed water the same amount was.applied to each pot and periodically the pots were brought to a 15 percent moisture level. On October 12, when the oats had reached the milk stage, they were cut at the soil level, dried in an oven at 650C, weighed, and ground to pass a 40 mesh screen. On December 20, 1965, a second crop of oats was planted at a depth of about % inch without disturbing the 'fertilizer band established at the first planting. With the 31 exception of N, this crop was given no additional fertilizer. This crop was harvested on March 20, 1966 just as the oats began to ripen. Yield Determinations in the Field In Montcalm County, potato vines were harvested on September 10, in order to determine the total dry weight yield of vines. The potatoes were harvested and yield determinations made on September 28, September 29, and September 23 in Otsego, Houghton and Montcalm Counties respectively. At all three locations, about ten pounds of number one potatoes were selected at random from each plot. A few weeks later, the specific gravities of these potatoes were determined using the hydrometer method. Laboratory Analyses Soil Tests Two soil samples per plot were taken in the field, one a few weeks after planting and the other just before harvest. Each sample consisted of 40 to 50 cores taken to a depth of about seven inches from between the potato rows. These samples and the sample from the greenhouse were air dried, ground, mixed, split with a soil splitter, and sent to the Soil Testing Laboratory at Michigan State University. In this laboratory, Bray's P method (45) was used to extract 1 32 the P, and P was determined colormetrically by the molybdenum blue method. After extraction from the soil with l N NH4Ac solution, K was determined with a Coleman model 21 flame photometer, Ca with a Beckman model DU quartz spectrophoto- meter and Mg with a Perkin-Elmer model 290 atomic absorption spectrophotometer. The soil pH, of a 1:1 soil to water sus- pension, was determined using a glass electrode with a calomel electrode as a reference. In order to obtain an estimate of the amount of Mg + 4 ions from the NH4Ac extracting solution, two soil samples trapped between the layers of the soil clays by the NH from each field location were extracted with 0.1 N NaCl, which contains the expanding Na+ ion. Fertilizer Analyses In order to verify its formulations, the Tennessee Valley Authority determined the total N, P, K, and Mg in the treatment fertilizers. In addition, total Mg was determined at Michigan State University. For the first Mg determination at Michigan State University, each sample was taken from near the top of the fertilizer bag. For the second set of determinations, each sample was taken to the bottom of the bag with a sampling probe. The samples were digested at 180°C in a mixture of concentrated HNO3 and HCl at a ratio of 1:1. Magnesium was determined by the use of the Perkin— Elmer model 303 absorption spectrophotometer. 33 Plant Analyses In Otsego and Montcalm Counties, two petiole samplings were taken from each plot. In Otsego County, the samplings were made on July 22 and August 16, 9 and 12 weeks after planting. In Montcalm County, the samples were taken on July 21 and August 26, 9% and 15 weeks after planting. Each petiole was taken from the youngest fully expanded leaf on the potato plant, usually the fourth or fifth leaf below the growing tip. Approximately 40 of these petioles were se- lected at random from the center two rows of each four row plot in Montcalm County and from the center row of each three row plot in Otsego County. In Houghton County, one petiole sampling was made on August 8, about 10 weeks after planting, using the same method as in Montcalm County. O The petiole samples were then dried at 650C and ground to pass a 40 mesh screen. These samples, the oats from the greenhouse, and the potato vines from Montcalm County were wet digested with nitric and perchloric acid, as described by Jackson (45). Mg and Ca were then determined by use of a Perkin- Elmer model 303 absorption spectrophotometer using 285 and 212 my wavelengths, respectively. K was determined by use of a Coleman model 21 flame photometer. RESULTS AND DISCUSSION Soil Test Results The soil test results are given in Table 3. Since the first samplings in the field were taken from between the SO potato rows after KCl and (NH had been broadcasted, 4)2 4 the available K values were higher than they were prior to establishing the experiment. However, the available P, Ca, and Mg values should reflect their respective levels before the fertilizer in 1965 was applied. The measured available nutrient levels at each lo- cation varied substantially between individual plots. Vari- ation in available nutrient levels may have contributed to non-treatment variation in yields and the Mg content of the potato plants. The soil test results indicate that the amount of available P in the Otsego County soil was lower than the greenhouse soil or the soils in Houghton and Montcalm Counties. Therefore, there should have been a greater re— sponse to P fertilization in Otsego County. The available soil K values in the field were lower at the end of the growing season than at the beginning. This was probably the result of leaching and K uptake by the 34 35 .THQMHUMHHNO Dd v .Heom no mooooo ooo.ooo.m H @UHHw 30HH5M THUM HO THUG @CO m2 mHmB m2 pCm MD «M “UOCDmE Hm mmmum an UmCHEHmumc m mHQmHHm>m N H oH omo omm AHA o.m seepemso meow Ion memu mHmEmw UCmm MEmOH mmson prmOQEoo CHHMmM IComuo we owe mam oam m.m mo\oa\o emoeeoez Ume mamOH .NUCCOU om emo ooe osm o.e mo\va\o mcoaooomz samoucoz mm mum oom Hoe o.e mo\oH\o smoa sameness mpcmm mCHm .mquoo Hm omo mom mofi m.e mo\m\e mesmeeoz eonemoom me emos «om mm m.m mo\e\o sameness UCmm >EMOH .MuCSOU me omma mew me o.m mo\am\o ceases ooompo IIIIIIIIIIIIIII menom\m©CsomIIIIIIIIIIIIIII mm m2 m0 M, m COHuommm mCHHmEmm mama COHumooq oHanHm>< oenmsemam oHanHm>m oanmaem>m HHom mo mums Heow .mmSOCCmmHm map CH HHow on» UCm pHme, on» CH mHHOm moans wCu HOM muom mom m: H UCm mo .M .m mHQmHHm>m pCm mm ommnm>¢ .m mHQmB 36 potato plants. Since the greenhouse soil sample was taken from before KCl had been applied, it tested lower in K than did the first field samples. There were no differences between the amounts of soil Mg extracted by 1.N NH4Ac as compared to O.1_N NaCl. This does not necessarily indicate that only a small portion of the clay fraction of each soil consisted of collapsing vermiculite and montmorillonite clay types. Because the soils contained abundant K, large amounts of Mg may have been trapped between the clay layers before the soils were ex- tracted. Since this Mg was unavailable to plants, the 1_N NH4Ac method probably accurately measured the amounts of available soil Ma. The available Mg values were below 75 pounds per acre. This along with the high available K levels should have resulted in responses to Mg fertilization, especially in the greenhouses and at the location in Houghton County. FertiliZer Analysis In general, for total N and K20, there was good agreement between Tennessee Valley Authority's (T.V.A.) formulated analyses and chemical analyses. But, the values for total P205 and Mg did not agree as well (see Table 4). Calculations for the fertilizer rates were based on the formulated analyses. According to the chemical analyses, the P rates were about 160 pounds of P per acre for the 205 37 ¢.m m.m m m ©.mH «.mm m.v oo.m N.mH o.v~ m.¢ mmn CUHB m mUHmoCmmz prHUHmoCD m.m m.m H.m v.hH H.nm m.m oo.m m.mH o.vm m.v mma CDHB h muHmmCmmE meHonU o.m m.m h.m ®.mH m.¢m H.m oo.m N.mH o.vm m.v awn CuHB o oUHosum poCHUHmO ma.o oa.o oomssmem uoz o e.oH o.em o.m mu: m m.m m.a e.m o.mH o.oa o.m om.m m.mH H.mm H.e no: sea; ooabcoobom. e o.m ©.N m.m 0.0m n.mH m.¢ oo.m m.mH o.¢m m.¢ no: CuHB m wuHmmCmmE meHonoCb m.m n.m m.m N.mH H.mH m.¢ oo.m N.mH o.vm m.¢ mo: CDHB m mUHmmCmmz meHUHmU h.m m.H m.m h.mH m.mH m v oo.m m.mH o.¢m m.v mo: CHHB H muHosum UmCHonO lllll AX. Ill Illlllllllllnxellllllllll Illllllllllbkulllllllll m m z s as ems meme 2 a: 0mm m0mm z CCH CSH CoHumHHUme HwQECZ pCoowm umHHm H AquEumoHEv m .D.m.2 um mmmxHMCfl HmoHEmCO MMMMHMHMMH HwNH a Hem UmuospCou .H.u mmmemCm .meNHHHuHmm HmprEHummxm was NO mommHmCfl .¢ mHQmB 38 .quHmz an pCmonwm CH mommHmCm HHd m .muHmm EOmmm I Ommh.¢ommz “mu: pCm mumcmmoam ECHCoEEmHQ I man “mumnmwonm ECHUHMUOCOZ I AUEH be.o Hm.o bonsamem uoz o m.oa o.e~ o.e one spas vommz NH H.m o.H v.m m.>H o.mm m.v vm.m m.mH m.mm m.v mwn CuHB MmeCmmE HH Ibmmuoo mo mummaom Hm.o mm.o bonsamom noz o N.oa o.em o.e one oa N.m ¢.N m.m h.mH h.¢N m.v oo.m m.mH ©.mm m.¢ méfl CUH3 wCHHCmmHmm m 39 treatments which included DAP (6—10 and 17-20) and 130 pounds of P20 per acre for the MCP treatments (1-5 and 13— 5 16). Calculations for the 20 pound per acre Mg rates were also based on the formulated analyses. The chemical analyses indicated that the actual Mg rates ranged from 17 pounds per acre, for treatments four and six, to 22 pounds per acre, for treatment nine. In general, for the analyses conducted at Michigan State University, the total Mg values for the first set of determinations were much lower than for the second set. Since each sample for the first set of determinations was taken from the top of the fertilizer bag, whereas each sample for the second set was taken to the bottom of the bag with a sampling probe, the analyses probably indicate that there was segregation of the powered Mg sources. This could have resulted in Mg rates generally lower than 20 pounds per acre and quite variable. Greenhouse Studies Application of Mg fertilizer increased dry matter yield, Mg content and Mg uptake of the first crop of oats (see Figures 2, 3, and 4 and Table 1A in the Appendix). For those 10 treatments which included the five Mg sources—~MgSO4-7H20, calcined brucite, calcined and uncal— cined magnesite and serpentine applied with two P sources MCP 40 .mouo umnHm IIm mo HmHnnmo pCm m2 m0 HoHHnmo UCm mums mo CoHuoCsm m mm muCMHm umo mo UHwHN mmn CpHB UmHHmm< whom mom 0: mo mpCsom mo: CuH3 pwHHde wHU< Hem m2 mpCsom as. am on as a ow om mm on .m musmHm _M. oCHqumHmm AMEuHmoCmmz meHonUCD MW muHmmCmmE prHonO VA muHosnm meHonU O ONE . e0% 62 lIoo.hH Yield of oat plants (g/pot) l A. mfln CHHB pmHHQmm mno< Mom m2 mpCsom a .0. mm a... aw .Qouo umHHMIJm mo HoHHHmU pCm 02 HO HmHHHmo pCm mums mo CoHuoCsm m mm mquHm umo mo pCmuCoo m: .m mHCmHm mo: CpH3 pmHHmmm whom and m: upCsom -mm JN aH m— oCHUCmmumm AOV ouHmoCmmz meHonUCD VR.muHmemmz UwCHUHmO VA wUHosum omcHono Av 0mCH.eommz .Iomo o IOOH. .TOHH. IONH. TIomH. lovH. OWH. Mg content (%) .monu umHHm IIm mo HmHHHmo pCm m2 m0 HwHuumo oCm mums mo CoHHUCsm m mm m: mo mxmumb .w mquHm men CDHB poHHQmm muom Mom 02 mpCsom. mu: CuH3 pmHHmm4 whom Hem m2 mpCsom ow om om OH o 0% mm om OH O P _ _ C P _ . p E - mCHpCmmHmm vapHmmCmmz QoCHUHmoCD .¥fi ouHmmCmmz meHUHmU anA wsHoUHm GoCHUHmO 4 . . O 0mm?a ommz Mg Uptake (m.e./pot) 43 and DAP at a Mg rate of 20 pounds per-acre (treatments 1—4, 6-9, 14 and 18), the differences in dry weight yield of oat plants were statistically significant at the one percent level (see Table 5). This primarily reflects the variation in the availability of Mg from the five Mg sources, rather than in- fluences of the two different P sources. Although the differ— ences in dry weight yield between the various Mg source treatments were not always larger than the honestly signifi- cant differences1 (see Table 5), definite trends are evident. When the Mg sources were applied with MCP, calcined magnesite and MgSO4°7H20 resulted in the highest dry weight yields, calcined brucite in moderate yields and serpentine and uncal— cined magnesite in the lowest yields. When the Mg sources were applied with DAP, calcined brucite and MgSO4°7H20 re— sulted in the highest yields, calcined magnesite in moderate 'yields and uncalcined magnesite and serpentine in the lowest yields. The sulfate of potash—magnesia treatment (number 11) resulted in a dry weight yield which was only surpassed by the calcined magnesite with MCP treatment. (Table 1A in the lH.S.D., or the honestly significant difference is part of Tukey's test and is calculated from the following equation: H.S.D. = 34.3%,, where “. is a constant which has been compiled in table form forcx.= .01 or .05, similar to the way in which the constant t is tabulated for the L.S.D. test, and Sx is the standard error of the difference between two means. The H.S.D. test is similar to the L.S.D. test, but is more severe and probably gives a more accurate estimate of the significant difference when there are more than a few treatments in an experiment. 44 .uom\.m.Ev ... Cooum H mm .mH pCm «mlo .CH .vIH muw3 mUCmEummHu mmmCB .muom \.wnH om mo mums m2 m um .mHmemmEICmmuom mo wUMMHsm umwoxw .mmUHSOm m2 may mo HHm popsHo ICH CUHCB mquEummnu mmonu Eoum numb How UmuospCoo mno3 mUCMHHm> mo mmmemsm H Ho. Ho. mo. so. mo. mo. woemoamaemam no Ho>oq mooboom m one a: MC COHuomumuCH Ho. Ho. Ho. Ho. Ho. Ho. outmoamacmam no Ho>oq mouoom as oH.A oH.A oH.A oa.A oH.A oH.A outmoameemam mo Ho>oq moboom a was. ems. mamo. momo. III mma.m .oocmoemeooam mo Ho>oa so. no .n.m.m eea. ama. mmao. meao. mam.a Nmm.a outmoamacmam “coaumoba mo Ho>oa mo. um .e.m.m Ho. Ho. Ho. Ho. mo. Ho. outmoamaeoaw mo Ho>og mono mono, mono mono mono mono mUCMHHm> mo wousow GCOOOm UmHHm @COUOW umHHh Ucoomm UmHHh weapon ucouooo mncmHm poo m: as no 6HmHM .EHOm CmmHm CH mum umsu mumc mo muom mmUCHUCH mHCB .UCGEHmexm mmCOCCwmum mCu EOHM mump mo mUCMHHm> mo mmthMCm How muHsmwm .m mHnt H 45 Appendix.) However, the check treatment (number 12) re— sulted in a yield which was substantially higher than for the other two check treatments (numbers 5 and 10). Magnesium content and total Mg uptake were closely related to dry matter production (see Figures 3 and 4, Table 5, and Table 1A in the Appendix). This data indicates that the order of availability of the Mg sources when applied with MCP‘was calcined magnesiteiQ; MgSO4'7H20 > calcined brucite é: uncalcined magnesite g serpentine. When the Mg sources were applied with DAP, the order was MgSO4°7H20:£ércalcined magnesite g calcined brucite > serpentine £5:- uncalcined magnesite. From the Mg content and uptake data, it appears that sulfate of potash-magnesia released as much or more Mg than did the other five Mg carriers. For thesecond crop of oats, there were no signifi- ‘cant treatment differences in dry weight yield (see Table 5 and Figure 5). Although there were not as many significant differences as for the first crop, the Mg content and Mg up— take data for the second crop indicate that there were resi- dual effects from the Mg sources. The trends in Mg content and uptake also support the conclusions drawn from the first crop data. Probably there were no responses in dry matter production, to Mg fertilization, because other environmental factors were more limiting to growth than the supply of available Mg. 46 .mouo pCooomIIm mo uoHHumo oCm m2 wo HoHuumo pCm mpmu mo COHuoCsm m mm mHCmHQ umo mo UHwHM .m onsmHm mam CDH3 UmHHQO whom Hem m2 mUCdom ON PI 0% 0m P _ B mCHUComHom AOV wuHmmCmmz @mCHUHmUCD ynoHHmmCmmz UwCHUHmO V4. mUHosum poCHono .N O o E . @0082 XX wH m0: CUHB pmHHmmm mnom Hem m2 mpCCom o 0% — Om P ON p CH C Tooo loo.m Yield of oat plants (g/pot) .monu UCoommIlm mo HmHnHmo pCm 02 Mo HmHHHmo UCm mama mo COHuUCsm m mm mquHQ umo mo “CmUCOU m: .m onsmHm mam CuHB pmHHmmm muom Mom 0: prCom m02.CpH3 UOHHmmm whom Mom 02 mUCsom we mm mm [I mH 0 We .%m .%m . mm B wCHquQme . AOV prmemmE l . . Iomo. I meHonoCD .¥%uHmoCmmz prHonO muHosnm meHono 7x .JU. cm a me. 0mm: Mg Content (%) .QOHU UCoomm IIm mo HmHHHmU pCm m2 mo HoHHHmo UCm open mo CoHuUCCm m mm m2 «0 wxmumb .b mHCmHm Add fluH3 mUZ £HH3 pmHHmmm mnom Hem m2 m0 mpCsom pmHHde muom Hem m2 m0 mpCCom ow om om 20H o 0% om . om OH. o T p _ _ VWI m p . E. _ wCHprmHom r l 00v; QwunmCmmE UwCHonoCD v3 mpHmmcmmz UmCHOHmO VA epHosum UmCHonO w O ONE . aowes E Mg‘Uptake (m.e./pot) 49 It should be noted that when applied with MCP, cal- cined brucite resulted in much lower dry weight yield, Mg content, and Mg uptake values, than when it was applied with DAP. For calcined magnesite, however, these values were somewhat higher When it was applied with MCP. This is diffi- cult to explain, since both of these minerals should have contained largely MgO. Field Studies A summary of the field data for the three field lo- cations is given in Table 6. Dry weight yield, Mg content, and Mg uptake data for potato vines were taken only in Mont- calm County. The average yield of potatoes for the three 10- cations and the dry weight vine yields show that there were small responses to Mg fertilization. Check treatments 5 and 10 resulted in somewhat lower potato yields. Check treat— SO in the mixed fertilizer in- 2 4 stead of the KCl used for treatments 5 and 10, resulted in ment 12, which included K the second highest potato yield, but produced one of the lowest vine yields. The differences were not great enough or the trends definite enough to draw any conclusions from the yield data concerning the order of availability of the Mg sources. In general, the average Mg content of the petioles for the first samplings and the Mg content of the potato vines were not closely related to the average potato yield and vine yield, respectively. Also, from the Mg content and 50 m.mH mom. comm me. SHN om m oumu IHumm mo mwoumuom .meH> an .mmCH> mo Iom pHmHM qupCoo m2 m0 pHme 02 mxmpmb quuCou m2 quHmS hum wmmnm>< mmmuw>¢ .mCoHmeoH mmHCp HHm Mom mpmp pHon mo mumEEsm .m oHQmE 51 .moz pCm mumnmmogm ECHCoEEmHQ I mmn umpmzmmonm ECHUHMUOCOE I mo: H ~.m mam. ooom ems. omm o man sees eowns NH m.HH mam. ommm moH. mam om men bees mamocmms Ha Iemmuoo mo mummaom o.o omm. ommm ems. mam o man oa H.oH mam. oemm boa. Nam om man bees omme.aommz ma o.oH omm. ommm NeH. mmm om men spas ocaucmnnom o e.o mam. omem HmH. emm om man sees m mpHmmCmmz prHonoCD 52 uptake of potato vines, it is difficult to draw any con— clusions for the order.of availability of the Mg sources. But, the average Mg content values for the first petiole samplings indicate that when applied with MCP the order of availability of the Mg sources was calcined magnesite > O > or 2.: calcined brucite > uncalcined magnesite Ll.“ MgSO -7H 4 2 serpentine and when applied with DAP, MgSO '7H20 > calcined 4 magnesite2§ calcined brucite > serpentine > uncalcined magnesite. Otsego County In Otsego County, the treatment differences in yields were significant'only at the 10 percent level (Table 3A in the Appendix). The Mg sources did not contribute significantly to these treatment differences. However, the influence of the two P sources on yield was statistically significant at the 5 percent level. The average yield for the MCP treatments (1-5 and 13-16) was 207 c.w.t. per acre and for the DAP treatments (6-10 and 17-20) it was 234 c.w.t. per acre. The soil test results indicate that the supply of available soil P was relatively low at the location in Otsego County. Since on the basis of the chemical analyses of the fertilizers the DAP treatments received 160 pounds of P205per acre and the MCP treatments 130 pounds of P205 per acre, there was apparently a response to P fertilization at this location. 53 Table 7. Results for analyses of variance of data from the field experiment in Otsego County. This includes sets of data that are in graph form.l Mg Content of Mg Content of Source of Petloles 2 Petloles 3 Variance First Sampling Second Sampling Level of Significance > .10 .10 Treatment H.S.D. at .05 Level of Significance —-- --- H.S.D. at .01 Level of Significance —-- --- Level of P Source Significance > .10 > .10 Level of Mg Source Significance > .10 > .10 Interaction of Mg and Level of P Sources Significance > .10 .05 1Analyses of variance were conducted for data from those treatments which included all the Mg sources, except sulfate of potash—magnesia, at a Mg rate of 20 pounds/acre. These treatments were 1-4, 14, 6-9, and 18. 2First sampling made on July 21, 1965, 9% weeks after planting. 3Second sampling made on August 26, 1965, 15 weeks after planting. 54 For the first petiole sampling, although the effects of the P sources were not statistically significant (see Table 7), the Mg content of the petioles was generally higher for MCP than for DAP (see Figure 8). Since the potato yields were higher for DAP, perhaps the lower Mg content for the DAP treatments was the result of a dilution effect. This ef- fect was less pronounced by the time of the second petiole sampling. On the basis of the Mg content of the petioles, there were no consistent differences between the effects of the two P carriers on the order of availability of the five Mg sources. Although there were no significant differences in the Mg content of the petioles between the five Mg sources (Table 5 and Figures 8 and 9), it probably can be said that '7H the M980 2O, calcined brucite and calcined magnesite 4 treatments resulted in higher Mg contents than the uncalcined magnesite or serpentine treatments. It should be noted that in the case of the calcined magnesite with DAP treatment, the Mg content of the petioles for the second sampling was very low. It is difficult to attribute this to experimental error since the same treatment resulted in a relatively higher value for the first petiole sampling.f When calcined brucite was applied with MCP, the re- sulting Mg content was slightly higher than the value for 55 .mquou ommmuOIIm mo HwHHHmo UCm OZ «0 HoHHHmU UCm mums mo CoHuoCsm m mm AOCHUCMHQ Hmumm mxmmz mv momH .NN hHsb .moHOHuwQ oumpom mo “prCoo m2 .m musmHm “:3 its oofloom no: :33 633% whom Hem m2 m0 mOCsom wuom Hem m2 m0 mpCsom 04.. cm ON OH O Ow 0m 0m OH O . . L L m a. . m m— mCHqumHmm QwUHmmCmmz meHonoCD I IOHH. vfl mUHmeOmz meHonU X muHosnm meHonu O Owneeomoz q T 1IONH. O n. X Or Toma. O x m .l [1. . * SH 0 o o O l hOmH. Mg Content (%) 56 .mUCsoo ommmUOIIm mo HwHHumo OCm 02 mo HoHHHmo OCm mpmu mo COHuoCCM m mm Ameaeemae House memos may moms .OH umsmsm .meoHumm oumuom mo quuCoo m: .m musmHm man no: CuHB OwHHmmm muo< Mom OE mOCsom CuH3 OwHHQmm wuod Hem m2 mOCsom O O flw wm ON _H O we om m 0% w B . mCHquQHmm vauHmmCmmz meHUHmoCD vR muHmmCmmz OmCHonO VA muHUCHm OmCHUHmU O ONE Home: IOMH. TowH. lOmH. OOH. IOhH. Mg Content (%) 57 calcined brucite with DAP. Although this did not agree with the data from the greenhouse study, it is the expected result. The Mg content of the petioles for the sulfate of potash-magnesia treatment (number 11) were not significantly different from.those for the other five Mg sources or treat— ment 12, the check for the sulfate of potash-magnesia treat- ment (see Table 3A in the Appendix). .Houghton County The response to Mg fertilization in yield and Mg con— tent of the petioles was greater in this county than at the other two locations. This is evident when the yields for the zero and ten pounds per acre Mg rates are compared (see Figure 10). However, there were no consistent trends in yield for the five Mg sources. Apparently, for those treat— ments above ten pounds of Mg per acre, there were other factOrs limiting growth. The differences in Mg content of the petioles due to treatment were statistically significant and greater than the differences at the other two locations (see Table 8 and Table 4A in the Appendix). The Mg content of the petioles indicated that the two P sources had no significant effect on the average availability (see Table 8) or the order of availability of the Mg sources (see Figure 11). But it should be noted that calcined magnesite when applied with DAP resulted in a lower Mg content than when applied with .hpCsoo CoqusomIJm mo HwHHHmo OCm m2 m0 HoHHHmo OCm spam we CoHpoCsm m mm mHmQCu oumuom mo OHwHM .OH mHCOHm Add mus CUHB OOHHQQH whom Hem OE mpCsom CuH3 OmHHmm< muom Hem m2 mpCsom ow om ON .I OH O owfi Om om OH O blI b . . p . _ . E mCHqumnom I _ "I ONH . Q - munmCmmS ) meHUHmUCD I .IOmH.m vwmuHmemmz meHono m 6K muHosum OmCWonu I . rIOVH.m. m G ONE. one: 6 .l OmH.t w c I IOOH.(. M a l @ EA I 9 fl- 0 E Y 0 O I Q Iowa 9 T G lomH. X 0 I . 1oom. 59 Table 8. Results for analyses of variance of data from the field experiment in Houghton County. This in- cludes sets of data that are in graph form.l Source of Yield of Mg Content Variance Potatoes of Petioles Level of Significance > .10 .01 H.S.D. at .05 3 Treatment Level of Significance --- .041 H.S.D. at 001 3 Level of Significance --- .049 P Source Level of Significance > .10 > .10 Mg Source Level of Significance > .10 .01 Interaction of Mg and P Sources Level of Significance > .10 .05 1Analyses of variance were conducted for data from those treatments which included all of the Mg sources, ex- cept sulfate of potash-magnesia at a Mg rate of 20 lbs./acre. These treatments were 1-4, 14, 6-9, and 18. 2Sampling made August 8, 1965, 10 weeks after planting. 3Percent. .mquoo CounmsomIIm mo HmHuumo pCm m2 m0 HwHuHmo pCm mums mo COHpoCsm m mm AmCHpCmHQ umumm mxmmz OHV mme .m umsmsm .moHOHHwQ oumuom mo pCmpCoo 02 .HH musmHm mmn CUH3 muz CuHB OmHHmmm wuofl Hem m2 mOCsom UwHHQO wnom Hem m2 mOCsom ow Om ON OH O 0% Om ON 0% O _ p _ _ I . p r INmO. E mCHUCmQHom muHmmCmmZ l . AW meHonoCD IOOH mUHmoCmmZ X omoaoamo G E Hod. VAmHHUCHm OmCHUHmU v w 0 cmmeeomms T Iowa. 0 I “MN IOmH. I . 33. O I O J3. O .I X 83. Mg Content (%) 61 MCP. There was no difference for calcined brucite between the two P sources. The Mg content of the petioles for the sulfate of potash-magnesia treatment was as high or higher than for any other Mg carrier (see Table 4A in the Appendix). Montcalm County At this location there were no significant differ- ences or trends in yield (see Table 5A in the Appendix), nor was the Mg content of the petioles closely related to the yield. For the second petiole sampling there were no sig- nificant differences due to the Mg sources or the P sources (see Table 9). However, according to the statistical an- alyses in Table 9, the variation in the Mg content of the petioles from the first sampling was due primarily to vari- ation in the availability of the various Mg sources. The trends in Mg content for the first petiole sampling were not as evident as for the other two locations (see Figure 12). It can be seen, however, that when applied with MCP, cal- cined magnesite supplied more Mg than the other Mg carriers. But the availability of calcined magnesite was lower when it was applied with DAP. The P sources had no apparent effect on the availability of calcined brucite. Uncalcined magne— site supplied the smallest amounts of Mg. The sulfate of potash-magnesia treatment resulted in the highest Mg content of the petioles from the first sampling (see Table 5A in the Appendix). 62 Table 9. Results for analyses of variance of data from the field experiment in Montcalm County. This in- cludes sets of data that are in graph form.l Mg Content of Mg Source of Petioles Content Variance of Vines First Second Sampling -Samp1ing Level of Significance .01 > .10 .10 H.S.D. at .05 Treatment Level of 4 Significance .040 —-— --- H.S.D. at .01 Level of Significance .044 --- --- Level of P Source Significance > .10 > .10 > .10 Level of Mg Source Significance .01 > .10 > .10 Interaction oerg and P Level of Sources Significance .05 > .10 > .10 1Analyses of variance were conducted for data from those treatments which included all the Mg sources, except sulfate of magnesia, at a-Mg rate of 20 pounds/acre. These treatments were 1-4, 14, 6-9, and 18. 2First sampling made July 21, 1965, 9% weeks after planting. ' 3Second sampling made on August 26, 1965, 15 weeks after planting. 4Percent; 3 6 .muCCOU EHmouCozIIm mo HmHHnmo UCm 02 mo HwHHnmo pCm mums mo CoHuoCsm m mm AmCHpCmHQ uwumm mxmm3 mmv mmmH qm >Hsb .meoHuwm osmuom mo quUCoo m2 .NH ousmHm mmn CuHB mo: CHH3 OmHHmmm mnom Hem m2 mOCsom OwHHmmm whom nod 02 mOCsom Ow Om ON OH O OO Om ON OH O . . r _ p WW _ . . I H I IOmH. E wCHquQHmm AmduHmmCmmz OmCHUHmoCD X ounmCmmz OmCHUHmU HI .IOHeH X wuHosum OmCHUHmu l iOmH. O ONEHOmmz AN I A“ .83. O 10:. a a m 0 em 1 VA JOmH. O a I road 9 I .0 .88. Va 9 nu l IOHN. Mg Content (%) 64 (As mentioned earlier, there were no significant treatment differences in dry weight vine yields or Mg uptake by the vines in Montcalm County (see Table 6A in the Ap— pendix). The differences in Mg content of the vines were significant only at the 10 percent level (see Table 6A in the Appendix). The Mg content of the vines indicated that both calcined magnesite and calcined brucite were consider— ably more available when applied with MCP than when applied with DAP (see Figure 13). This is not consistent with the greenhouse data, but is the expected result. There were no significant treatment differences in specific gravity of potato tubers for any of the field lo- cations. But, in Houghton County the specific gravity read- ings were substantially higher than the other two locations. (The average specific gravity in Houghton County was 1.077, whereas the average reading was 1.058 for Otsego and Mont- calm Counties (see Tables 3A, 4A, and 5A in the Appendix). Comparison of the Mg, Ca and K Contents of the Oat and Potato Plants The average Mg contents of the greenhouse oats and potato vines in Montcalm County were .11 percent and .32 per— cent respectively. These values are somewhat lower than those obtained by Tobin and Lawton (110) who on a sandy soil ianichigan found that oats and barley had an average Mg con- tent of .16 percent, whereas the average Mg content of potato vines was found to be .40 percent. Since the soil in Tobin .mquoo EHmouCoEIIm mo anunmo pCm m2 m0 HmHHHmU OCA mums m0;CoHuoCsm m mm mmCH> oumuom mo #Cmucoo OE .mH musmHm mfld CUHS . ADE £HH3. pmHHmmm mnom Hem m: mUCCOm OwHHmmm whom Hem m2 mUCCom ow om om , oH . o .oe om oml . oH ‘ o _ . _ p .p . _ b b E mCHqumHom I _ 1 OON . Q wuHmmCmmz Q meHUHmUCD . X wuHmmCmmS OmCHono a . I I. 3. 0mm. VA_ mHHosum OmCHonO H O . cameeommz 5 6 I oom. I omm . H owm . fioom. ;Ime. Mg Content (%) 66 and Lawton's investigation was not deficient in Mg, it is easy to understand why the Mg contents in the experiment were higher. It has been found that there are often reciprocal relationships between the contents of Mg, Ca, and K. Using the data for the first crop of oats in the greenhouse, simple correlations were calculated for all possible pairs of dry weight yield, and content and uptake of Mg, Ca, and K. For the data at all three field locations, all possible correlations between potato yield, and content of Mg, Ca, and K in the petioles were calculated. In Montcalm County, simple correlations were calculated for all possible pairs of dry weight vine yields, and content of Mg, Ca, and K in the potato vines. The results for these calculations appear in Table 10 and Tables 7A, 8A, 10A, 12A and 14A in the Appendix. Only in the greenhouse under more controlled con— ditions were there definite reciprocal relationships between percent content of Mg, Ca, and K (see Table 10). There were statistically significant negative correlations between the Mg and Ca contents and Mg and K contents. However, there was a positive correlation between the Ca and K contents. In addition, it should be noted that dry weight yield was positively correlated with Mg content but negatively corre- lated with the Ca and K contents. Since the supply of Mg was limiting to growth, decreases in Mg supply resulted in .AHV quHUHmwmoo CoHumeHHoo mo mUCmonHCmHm mo Ho>wH u m 67 m .quHUHmmmoo COHHMHeuHOU H mm .mHH n NIONH u Eoemmum mo memeH II OOO.H II II HO. Hem. HO. HOm.( HO. 5mm. OH.A who. HO. OOh. M mxmumb II OOO.H HO. mom. HO. mmO. HO. Ohm.l HO. mmm.I HO. heO.I quuCOU M II OOO.H HO. eeO. mo. OOH.I OH.A mNH.I OW.A th.I mo mMmuQD II OOO.H HO. NHO.I HO. eom.I HO. hmO.I pruCOU mo II ooo.H Ho. mom. Ho. «me. as oxmunp Ho. OOO.H Ho. mHm. pomucoo ms II II ooo.H oHoHH “CmHmS mun m u m u m. u m u m u m H mm «A x no booucoo s we peopcoo mu m: ucmucoo ms muomHm umo oxmuob mo memes: mo oxmuos mo oHon uanm3.%Hn .mmCOCCmon 0C» CH mumo mo mono umHHm mo “CmuCoo quHHusC pCm OHmHM uCOHmB MAO H.mHmMHMCm COHumHoHnoo mHQEHm .OH oHQmB 68 decreased yields. Because of the reciprocal relationships between Mg and Ca contents and Mg and K contents, the Ca and K contents were higher when the supply of Mg was lower. This probably explains the negative correlations between yield and Ca and K contents. Simple Correlations Between Potato Yield or Mg Content and Available Soil Nutrient Levels Simple correlations between potato yield or Mg con- tent and available soil P, K, Ca and Mg were calculated to aid in determining which nutrients were limiting growth and the degree to which variation in available soil nutrient levels resulted in non—treatment variation. However, few conclusions could be drawn from these correlations. The re- sults to these calculations are presented in Tables 9A, 11A, 13A and 15A in the Appendix. In general, there were no sig— nificant positive correlations between potato yield and available soil P, K, Ca or Mg. In Otsego County, since there was a response to P fertilization, it is reasonable to assume that the supply of P was limiting to growth. However, there was not a significant positive correlation between potato yield and available soil P (see Table iA in the Ap- pendix). In Montcalm County, where the response to Mg fertilization was the smallest, there were significant posi- tive correlations between Mg content of petioles or vines and available soil Mg (see Tables 13A and 15A). In this 69 county, variation in available Mg may have contributed to non—treatment variation in Mg content. But, since there were no significant positive correlations between yield and available soil Mg, factors other than the supply of soil Mg probably were more limiting to potato and vine yields. Multiple Correlations Between Yield or Plant Mg Content and Plant and Soil Nutrient Content Multiple correlations were calculated for potato yield as a function of Mg, Ca, and K content of potato petioles and plants and amounts of available soil P, K, Ca and Mg. They were also calculated for Mg content of petioles or plants as a function of Ca, K content of potato petioles and plants and the amounts of available soil P, K, Ca and Mg. As for the simple correlation analyses, these calcu- lations were made primarily to aid in determining which nutrients were limiting yield and the degree to which vari— ation in available soil nutrient levels contributed to non- treatment variation of yield and plant Mg content. However, no conclusions could be drawn from the results to the calculations. 70 General Discussion and Summary In both the greenhouse and the field, there were re- sponses to Mg fertilization. Yield, Mg content, and Mg up- take data for oats in the greenhouse and potatoes in the field showed that the order of availability of the Mg sources N when applied with MCP was: Calcined magnesite == (calcined N brucite) > or'Eé MgSO '7H20 > uncalcined magnesite=== serpen- 4 tine, and when applied with DAP the order was: MgSO4-7HZO > :2; calcined magnesite 2; calcined brucite > uncalcined magne— siteéaé serpentine. The availability of Mg from sulfate of potash-magnesia (Sul-Po-Mag) was about equal to that for 4'7H20. Greater responses were obtained in the greenhouse MgSO than the field because the soil used in the greenhouse con- tained a lower level of available Mg initially and there was less environmental variability. At one location in the field, the responses to Mg fertilization were small because the supply of available P was more limiting than the supply of available Mg. Field results were quite variable due to soil differ— ences, lower than average rainfall, and insect damage in one county. However, simple and multiple correlation analyses, including soil test results for P, K, Ca and Mg on individual plots did not explain much of this variation. Calcined magnesite was more effective when applied with MCP as compared to DAP. Since both the calcined 71 magnesite and calcined brucite contained largely MgO, it was thought that they would release more Mg in the acidic solu— tion around dissolving MCP than in the more basic solution around disSolving DAP. However, in the greenhouse, the yield and Mg content were lower for the calcined brucite with MCP treatment than for the calcined brucite with DAP treatment. In the field, these values were approximately equal for the two treatments. The chemical analyses of the treatment fertilizers indicated that there may have been more segre- gation of calcined brucite when it was coated on MCP than when it was coated on DAP. This may explain why the yield and Mg content were lower than expected when calcined bru— cite was applied with MCP. .The P sources had no effect on the availability of Mg from MgSO '7H 0, uncalcined magnesite, 4 2 and serpentine. 10. 11. BIBLIOGRAPHY Andrew, R. L. 1942. Reversion of calcium superphos- phate by serpentine. New Zeal. J. Sci. Technol. 233: 208-209. Askew, H. 0., and D. J. Stanton. 1942. Local prepar- ation of serpentine superphosphate. New Zeal. J. Sci. and Technol. 24B:79-85. Bartholomew, R. P. 1933. Availability of Phosphatic Fertilizers. Ark. Agric. Exp. Sta., Bull..289:3=l9. Bear, F. E., and A. J. Prince. 1945. Cation- equivalent constancy in Alfalfa. J. Amer. Soc. Agron. 37:217-222. Bear, F. E., A. L. Prince, 3. J. Toth, and E. R. Purvis. 1951. Magnesium in plants and soils. 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Karlin Series: The Karlin soils are well-drained Podzols which have de- veloped in loamy fine sand to fine sandy loam, 15 to 42 inches thick, overlying sand. Below 36 inches, weak, thin textural B horizons are often present. Karlin fine sandy loam Depth Horizon ,(inches) Description Ap 0-8 FINE SANDY LOAM; very dark grayish brown (lOYR3/2); very weak, fine granular structure; very friable; moderate in organic matter; slightly to medium acid; abrupt smooth boundary. 6 to 11 inches thick. AZ 8-9 SANDY LOAM; pinkish gray (7.5YR6/2-7/2); very weak, coarse, granular structure; very friable; medium to strongly acid; abrupt wavy boundary. 1 to 3 inches thick. \0 l B2ir 23 COARSE, SANDY LOAM; dark brown (10YR4/3— 7,5YR4/4); very weak, medium subangular blocky structure; very friable; medium to strongly acid; gradual wavy boundary. 9 to 20 inches thick. llB2 23—30 SAND; yellowish brown (10YR5/4-5/6); - single grain structure; loose; medium acid; gradual wavy boundary. 8 to 15 inches thick. llB3 30+ SAND; light yellowish brown (10YR6/4); single grain structure; loose; medium to slightly acid. 84 85 2. Munising Series: The munising soils are moderately well to well-drained Podzols with fragipanS, which have developed in strongly acid, reddish sandy loam glacial till derived from red sandstone. The parent material is more acid than either that for the Karlin or Mancelona series. Munising sandy loam Depth Horizon (inches) Description Ap 0-5 SANDY LOAM; dark brown (7.5YR4/2) to dark reddish brown (5YR3/3); weak, fine to medium, granular structure; friable; strongly acid; abrupt smooth boundary. 4 to 10 inches thick. A2 5—6 FINE SANDY LOAM; reddish gray (5YR5/2) to pinkish gray (5YR6/2); weak, thin platy structure breaking down into very weak, fine, granular structure; very friable, strongly to very strongly acid; abrupt wavy boundary. 0 to 5 inches thick. B2hir 6-10 SANDY LOAM; dark reddish brown (5YR3/3- 3/2); weak, fine to coarse, subangular blocky structure; friable; strongly to very strongly acid; gradual wavy boundary- 3 to 5 inches thick. B2ir 10-16 SANDY LOAM; reddish brown (5YR4/3-4/4); weak, medium to coarse, subangular blocky structure; friable; strongly to very strongly acid. 4 to 9 inches thick. A2x 16—25 SANDY LOAM; reddish brown (5YR5/3) to light reddish brown (5YR6/3) grading downward to reddish brown (5YR4/4-5/4) in lower part; weak, thick, platy to weak, coarse, subangular blocky structure; vesicular; hard; brittle; strongly cemented when dry and firm when moist; strongly acid; gradual wavy boundary. 6 to 11 inches thick. 86 B2t 25-40 SANDY CLAY LOAM; reddish brown (2.5YR4/4- 5/4) with some streaks and coatings of pale red (2.5YR6/2—6/3) on ped surfaces in the upper part; moderate, medium to coarse, subangular blocky structure; firm; strongly to very strongly acid; clear wavy boundary. 10 to 20 inches thick. C1 40+ SANDY LOAM; reddish brown (2.5YR4/4), red (2.5YR4/6) to light reddish brown (2.5YR6/4); some whitish loamy sand and sand lenses; weak coarse, subangular blocky to massive structure; friable; strongly acid. 3. Mancelona Series: The Mancelona soils are well to moderately well drained Podzols which have developed in either stratified gravelly and sand outwash or in unsaturated gravelly sand or loamy sand. They have a Podzol upper sequum and Gray WOOded lower sequum. The parent material of these soils is more calcareous than that for either of the other two series. Mancelona loamy sand Depth Mancelona ,(inches) Description Ap 0-7 LOAMY SAND; very dark grayish brown (lOYR3/2) or dark grayish brown (lOYR 4/2); very weak, fine, granular - structure; moderately high organic con- tent; very friable when moist; slightly to medium acid; abrupt smooth boundary. 6 to 12 inches thick. A2 7-10 SAND OR LOAMY SAND; gray (10YR6/l) or light brownish gray (10YR6/12); very weak fine, granular structure; very fri— able when moist; slightly to medium acid; clear wavy boundary. 0 to 6 inches thick. B21hir 10-15 LOAMY SAND OR SAND; dark reddish brown (5YR3/4) or dark brown (7.5YR3/2—4/4); very weak, medium, subangular blocky structure; very friable when moist; I A 2 B’2f IICl 15-33 33-36 36 87 medium acid to neutral; clear wavy boundary. 4 to 12 inches thick. SAND OR LOAMY SAND; yellowish brown (lOYR5/6), pale brown (lOYR6/3), or brown (lOYR5/3); very weak, fine, sub- angular blocky to single grain structure; very friable when moist; medium acid to neutral; clear wavy boundary. 6 to 9 inches thick. SANDY LOAM OR SANDY CLAY LOAM; brown (7.5YR5/4) or dark brown (7.5YR3/2-4/4); weak, medium, subangular blocky structure; friable when moist; neutral to slightly acid; abrupt irregular boundary. 2 to 8 inches thick. SAND AND GRAVEL; light yellowish brown (10YR6/4) or light gray (10YR7/2); loose; calcareous. 88 m.OH sw.e mm.H Hmm. mH.H OOH. mm.mH Om men CUH3 mCHqumumm m O.mH OH.m Oe.H woe. NH.H moo. em.mH Om man CuH3 m muHmmCmmE OmCHonoCD H.mH mm.e Om.H mom. 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NOO.H OmN ON mo: CuH3 N muHmmCmmE DOCHUHmU m.NH m.mH NOO. New. mOH. OmH. OOO.H OHN ON mo: CuHS H muHossm OwCHonO IIIII LSIIIIII IIIIIILSIIIII IIIIIIxIIIIII .e\u.3.o .e\.mns mmCHHm OCHHm mOCHHm OCHHm OCHHm OCHHm OZ CoHumHsommn stECz IEmm N.IEmm IEmm N IEmm m IEmm N IEmm mo mumm HHmNHHHuHmm OCoomm umuHm OCoomm umsHm OCoomm umsHm msmnse mo mquEpmosB mmHoHumm.mo meoHuwm mo mmHOHuwm no MuH>msO mstCB quuCoO M quuCoo mo uCouCoo m2 UHMHUmmm Mo UHon .MHCCOO ommmuo “OHmHm may CH wmoumpom How mumn .em mHQmB 93 .OCHDCMHm Hmuwm mxmoz NH .mCHpCMHm unumm mmeB m .mOmH .NN MHCO Co meme OCHHmEmm umsHm amOmH .OH umsmse Co mOmE OCHHmEmm OCoomm m m .muHmm EOmmm I onh.eommz “mos OCm mumnmmonm ECHCOEEmHn I men “mumCmmOCm ECHUHMUOCOZ I mOEH III III III III III III III III DUCmUHMHCmHm mo Hmamn Ho. um .n.m.m III III III III mmo. III III III wUCmUHmHCOHm mo Hw>mn mo. um .n.m.m os.A os.A os.A os.A mo. os.A III os. oosnosmssmsm.mo so>os s.ms m.ms oms. osm. mos. ees. mmo.s smm oe ommm.eommz one use om m.ms m.es oms. oom. oms. mes. smo.s oem om ommm.eomms.esm men as e.ms o.ms ode. smm. ems. mms. mmo.s amm om omms.eommz can men ms m.ss m.es sod. msm. mes. mms. mmo.s mmm os 0mmm.eommz can see es s.ms m.ms oee. emm. mos. mes. smo.s msm oe 0mmm.eommz can no: es m.ss e.ms oom. mam. oms. mes. mmo.s oms om omms.eommz can so: ms m.ss m.ms mmm. mmm. mes. mes. omo.s mos om omms.eommz can no: es m.ss e.ms msm. Hem. mes. oes. omo.s mom os omme.eomms can no: ms m.ss m.ms mmm. emm. mes. ems. Hmo.s msm o men sums eomms ms m.ss o.ms sme. mmm. mes. oms. mmo.s mmm om see sums osmosmms ss ICmmuom mo mummHCm m.ss m.ms eom. msm. mes. mms. smo.s mmm o nee os 94 0.0 HHO. OHH. NSO.H nOH ON men CHHB mCHqumswm O 0.0 HHO. OHH. NSO.H .OSH ON men CHHS O mOHmmCmmz OmCHonUCD 0.0 emO. OeH. OmO.H Omd ON men CuHB h OHHmmCOmE OOCHUHmU 0.0 OOS. OmH. SSO.H .Ome ON men CuH3 O eHHossm OmCHonO H.OH Ohm. eHH. OmO.H OeH O mu: m mm mmm. mos. tbs ens. om mos nus; osssconsom e 0.0 NOO. ONH. OmO.H OOH ON moz CHH3 m wuHmmCOmz OmCHonUCD H.OH eeh. OOH. Ono.H eOH ON mu: CuHS N wuHmmCOmE OmCHUHmU m.OH OmO. ONH. OhO.H NOH ON mo: CuHB H eHHussm OwCHUHmU IIILXIII IIILXIII IIILXIII .e\.u.3.o .e\.mQH wwHOHumm mmHoHumm mmHOHumm msmflCB msmnsa m2 HCOHumHHUmmn HwQEsz no Ho Ho no mo OHmHN mo mumm smNHHHuswm quuCOU quuCOU “COHCOU MUH>mHO NM Nmu NOE UHMHUmmm mquEummsB .Mquoo Cousmson “OHmHm was CH meoumuom sow mpmn .ee mHHmB 95 .OCHHCMHm Hmumm mxmm3 OH .mOOH .O undone meme OCHHmEmm N .muHmm EOmmm I ONMS. COOS “mu: OCm oumnmmonm ECHCOEEMHn I men “mumnmmosm ECHUHmUOCOS I mUSH II II meo. II II mosmossscmsm so so>os so. so .e.m.m II eem. mmo. II II ousmosmsnmsm mo so>os mo. no .n.m.m OH.A mo. HO. II OH.A mUCMUHmHCmHm mo Hw>wn m.os mmm. sos. seo.s omH oe ommm.eommz can see om o.os mmm. ass. oso.s mes om 0mmH.eomm2osm meal as s.os msm. mes. meo.s .oms om cmmm.eomms one see ms e.os mmm. mes. Ono.s oom os 0mma.eommz van men as m.os msm. mes. mmo.s -oms oe omms.eommz can no: es o.o mos. mms. omo.s .sss om ommm.eommz one so: ms m.os mom. mes. mmo.s oos om omme.eommz one sos. es m.os mom. ems. meo-s Doss os 0mme.eomms can so: ms m.o mmm. mos. mmo.s -oms o and buss eommx ms o.os oms. mes. meo.s ems om men nus: nsnosmms ss Inmmuom mo DUMMHCO m.o msm. mss. eso.s _ees o man os 96 o.os e.ms msm. mmm. oom. oms. mmo.s smm om see buss ossncoesom o O.HH O.HH mOm. eHm. OOH. HOH. OOO.H mnN ON men CHHB O mpHmmCOmZ OmCHonUCD O.HH O.NH OOm. NHm. OOH. OmH. an.H ONN ON men CHH3 n wuHossm OmCHonu O.HH m.mH th. Nmm. OmH. SSH. OOO.H enN ON men CuHB O muHossm OmCHonU O.HH m.NH NOm. Omm. NOH. mON. OOO.H HSN O mu: m m.ss m.ms mmm. mmm. mss. mss. omo.s msm om no: buss ossssoQHom e O.HH H.HH OOm. eOe. OmH. an. mmO.H OON ON mOE CHH3 m wuHmmCmmE OmCHonoCb O.HH O.HH Nem. mme. OmH. mON. OmO.H th ON mo: CHHS N muHmeOmE OmCHonU O.HH O.NH Oem. HOe. OOH. HOH. OOO.H eON ON mo: CuHB H ouHossm OwCHUHmO IIIII lxIIIII IIIIILXIIIII IIIIILXIIIII .e\u.3.o .e\.mQH mOCHHm OCHHm mmCHHm NOCHHm mOCHHm OCHHm Oz COHumHsUmmn stEdz IEmm N IEmO IEmO IEmO IEmO N IEmm . mo mumm HHmNHHHuswm OCoomm umsHm OCoomO umHHm UCoowm umsHm mummy? mo quEumeB mmHoHumm mo mmHOHumm mo mmHoHpmm mo MuH>mHO mHmHSB uCouCOO M quuCou mo HCOUCOO O2 UHOHUmmO mo UHmHM .MHCCOU EHmouCoE “OHmHm OCH CH mwosmuom How mpmn .em mHnmE 97 .OCHquHm Hmumm mMmm3 mH .mOOH .ON undone Co mOmE OCHHmEmm OCoommm .OCHHCMHm Hmumm mmeS wO .mOOH .HN MHCO Co mUmE OCHHmEmm umHHmN .muHmm Bowmm I ONMh.eOOOz “m0: OCm mumnmmonm EDHCOEEHmn I men “mumnmmonm ECHUHMUOCOZ I mOSH II II II II II II II II wUCmonHCOHO mo Hm>mn HO. um .n.m.m o.s II mms. mms. II II II II outmossssmsm so so>os mo. so .e.m.m mo. os.A mo. mo. os.A os. II os.A mosmosmssmsm so so>os s.ss e.ms oom. msm. ssm. ssm. mmo.s sem oe 0mmm.eommz can see om O.HH e.NH Omm. Owe. OOH. OmH. OOO.H mON Om ONMh.eOmOz OCm men OH e.ss m.ms emm. moo. mos. oms. Hmo.s mem om 0mms.eommz can men ms O.HH O.NH Omm. OOe. OOH. NhH. hmO.H OON OH ONM>.eOOOz UCm men pH o.ms m.ms msm. woe. mms. oms. mmo.s mmm oe omms.eommz com no: es O.NH N.NH Oem. Nee. mOH. OOH. OOO.H mbN Om ONM>.eomO2 OCm moz mH e.HH >.HH mOm. eOe. eOH. NSH. OOO.H mnN ON oNMh.eOOO2 OCm moz eH m.HH e.NH OmO. mOe. eOH. eeH. OmO.H NSN OH ONMn.eomOz OCm mo: mH e.ss m.ms mmm. msm. mos. oms. mmo.s mmm o nae buss eomms ms 0.0H e.NH Onm. mNO. OOH. OHN. smO.H OmN ON men CHHS MHmeOmE HH Isnmuom mo mummssm N mH m.NH mmm. mOe. mnH. OmH. OOO.H OSN O men OH 98 enH Ne.m m.ON OOO. 0.0H Omm. OmNm ON men CuHB mCHqumswm O OOH ON.m m.mN OOm. S.O OHN. Omem ON men CuHB O muHmmCOmz OmCHonUCD OOH OO.e O.eN mos. m.NH OOm. OOOm ON men CHHB n wuHossm OmCHUHmO mOH OH.m m.mN Omm. 0.0 OmN. OOHm ON men CHHB O muHoCsm OwCHonO OmH OO.e O.eN eNO. 0.0H Omm. OeOm O mu: m OOH Om.m O.eN mOe. m.HH HNm. OOmm ON m0: CDHB mCHHCwmsmO e meH OO.e 0.0N OOO. 0.0 OON. OOOm ON mo: CDHB m wuHmmCOmE OwCHUHMUCD OnH Om.m e.eN HNm. h.HH Oem. OOmm ON mo: CHHB N wuHmmCOmz UOCHUHmU OmN nm.O 0.0N New. H.NH OHm. OOOm ON moz CHH3 H mDHossm OwCHonO e\mnH X e\mnH X .e\mQH X .e\mQH .e\mnH M quuCoo mo quuCoo OE DCmuCOO mmCH> wxmumn M mxmumn mo wxmumn Oz «0 OS HCoHumHHwan stEDZ UHmHN mo mumm HwNHHHuHmm uses o3 Nun mquEummHB C0>O ll“, {I .meH> oumuom Mo quuCoo quHHHCC sMHCCOU EHmouCoz “OHme OCH CH mmoumuom How mumn .eO OHQmB 99 .muHmm Bowmn I ONMh.eOmOZ emu: UCm mumCmmOCm ECHCOEEmHn I men empmnmmonm EsHonUOCoE I mOEH II II II II II II II eUCmonHCOHm mo Hw>mn HO. pm .n.m.m II II II II II sms. II mocmosmscmsm mo so>ms mo. pm .n.m.m .os.A os.A os.A os.A os. A mo. os.A ooemosmssmsm mo seams ees ee.m o.os mse. o.os eem. osem oe omme.eomms one see om mes me.m m.sm emo. o.m esm. oesm om 0mme.eomms one see as mos om.e s.em ese. o.os mmm. oemm om cmme.eommz one see ms oes mm.e m.mm ems. s.os mom. oeem os omme.eommz one see es mes mo.m e.em see. m.ss oem. oemm oe 0mme.e0mms one no: es mms oe.m o.om ese. o.os oem. ommm om omme.eomms was so: ms mes es.m m.mm moo. m.os osm. ommm om cmme.eommz use no: es mos oe.m e.sm mse. o.m oom. omom os cmme.eomms can so: ms mms om.m o.mm eme. m.m mem. omom o men susz eomms ms mos om.m e.em ooe. m.ss msm. ommm om nee nus: msnosmms ss ICwmuom mo mHmMHCO oms om.m m.em sse. o.o mmm. ommm o men os 100 .Asv quHonmmoo CoHHMHmssoo mo OUCMUHHHCOHm mo Ho>mH H mm .quHUHmwmoo CoHumHmHHoo u AN .OHH n N I ONH u Eocmwsm mo mmeOmnH OOO.H OH.A mmO. OH.A mmO.I OH.A OOO. OH.A OHHII OH.A OeH. mo. ONN. M mMmumD II OOO.H OH.A HOO.I OH. mmH. OH.A meO. OH.A eOO. OH. eeH.I pCmuCoo M II OOO.H OH.A eOO. OH. NmH. OH. OmH.I OH. 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Oz UCfluCOU muCMHm umo mxmumb M exaumn mo mMmumn OS mo OHDHM Hmuoe uCOHOS Nun . . .omCOCCmmHO mCu CH wumo mo mono UCooom Ho quuCoo quHsusC UCm UHwHM HCOHmS mun .mHmmHmCm COHumHmssoo mHmEHm .ee mHnt H 101 .Asv quHUHmmoou COHHMHmssoo mo OUCmUHwHCOHm mo Hm>wH n m m .quHUHmmwoo CoHumHmHHOU n HN .Oe u N I OO u Eoewmsw mo mmmHOmnH II ooo.s os.A mos.I os.A mms.I os.A omo. os.A moo. os.A eos.I os.A emo. msssQEmm esoodm II ooo.s os.A mmo. os.A moo. os.A seo. os.A mos.I os.A eos. messesmm unsss nososuoe mo pCmuCOU M II ooo.s mo. omm. so. mse. os. esm. so. esm. messoEmm esooom II ooo.s so. esm. so. see. os.A mms. msssoEnm amuse mosesbme mo quuCoo mo II ooo.s so. eoe. so. sem. messesmm osooom II ooo.s os.A ess. meesnsmm unssm nosOsuom mo quuCoo OS II ooo.s noounuom no uses» m s m . s m s m s m s m H mm ms OCHHm OCHHm OCHHm OCHHm OCHHm OCHHm IEmm IEmm IEmO IEmO_ IEmm IEmm OCoqu umsHm ecouwm . umnHm OCOUDO umuHm . . wmoumuom mmHoHumm mo mmHOHumm mo mmHOHumm m0 m0 OHmHM HCOUCOO M quuCoo mo . . uCOUCoo O2 .Mquoo OOmmuO meHoHumm osmuom mo quuCou quHsusC OCm OHmHM HanmMHmCm CoHumHmHHoo mHmEHm .eO mHnt 102 .HHom Owss sHm .mmH OO.OOO.Nanoe ..Msoumso mH OCHuwww HHOO.>UHmsm>HCn msmum CmO IHCUHE esp um monumE ue mz mCu H 2 OCm mo .M OCm OOCumE m w.»msm Q OwCHEsmumO mmB me .Hsv prHUHmmmoo COHumHmHHOU mo mUCmonHCOHm mo Hw>mH H mm .quHonmmoo CoHumHessoo u sN .Oe n N I OO n Eoemmsw mo mmmsOmnH .OH.A OOO. OH.A O OH.A emO.I OH.A eHO.I mo. meN. OH.A OeO.I OH.A OOO.I mo. eNN. OCHHmEmw OCoqu OH.A emO. OH.A eeO. OH.A ONH.I OH.A OeH.I OH.A OOO. OH.A OOO. OH.A HHH.I OH.A HeO.I OCHHmEmm umsHm meOHumm mo quuCoo M OH.A mHO. OH.A OOO. OH.A OeO. OH.A OeH. OH.A OOO. OH.A OHH.I OH.A mmO.I OH.A OeH.I OCHHmEmm OCoomO OH.A eOO. OH.A NmO. OH.A OeH.I OH.A mmO.I mO. ONN. OH.A mNH.I OH. OHN. OH.A OeO.I OCHHmEmm umHHm _mmHOHummMOo “CwUCoo mo OH.A OHH. OH.A meH. mO. mNN.. OH.A NOO. OH. OOH. OH.A HNH. OH.A mmO.I OH.A mHO. OCHHmEmm OCoomm OH. OOH. OH.A eeH. OH.A omO.I OH.A OeH.I OH.A ONH. OH.A mmO.I NO. mON. OH.A NOO. OCflHmEmm umnHm meOHuwm mo quuCoo O2 OH.A mOO. OH.A meO. OH.A NmH. OH.A mOO. OH. OON. OH.A emH.I OH.A OmO. OH.A OOO. mooumuom mo OHwHM m u m s m .H m H m. H m. H I. m H m H m w a: mo M m as we M m OCHHmEmm UCoomO .muHsmmM umma HHom IOCHHmEmm umHHm .muHsmmM umma HHom V. IL II] 1||l ill ll. .MHCCOU OOmmuO mmustmH.Hmmu HHOM UCm mHoHumm oumuom mo quuCoo prHHusC .OHOHM HHmHmMHMCm COHumHmHHoo meEHm .eO wHQmB 103 .AHO HCmHUHmmmOU COHHMHwHHoo mo MUCmonHCOHw mo Hm>wH u m m .quHUHmmmou COHumHmHHoo u HN .Oe u N I OO u Eoemon mo wwHOwnH II OOO.H OH.A OmH.I OH.A mOO. OH.A mHH. mmHoHme mo qupCou M, II OOO.H OH.A mmH.I OH.A mOH. meHOHumm mo quuCoo mo II OOO.H OH. OHN. mmHoHuwm mo ucmuCOU OS II OOO.H mOOumuom MO CHOHN H . . H H H m m _ m mm N ucmusoo M unmucoo mo ucmucoo 82 mo esoHH ”mmHOHumm oumuom mo quuCoo quHHHCC OCm OHmHM H .MHCDOO COHCOSOM mmHmMHMCm COHHMHmHHOU mHmEHm .eOH oHHmB .HHOO OOHHO HHm OOCCom OOO.OOO.N n OHoe .MHOHmHOHmn OCHHOOB HHOO MHHOHO>HCD OHmHO CmOHCoHE OCH Hm OOCHOE Ueemz OCH MD O2 UCm m0 «M UCm UOCHOelfim O.MmHm an UOCHEHOHOO wm3 m e .AHO HCOHOHOHOOO COHHmHOHHoo mo OUCmOHmHCOHm Ho HO>OH H mm .HCOHUHHHOOU CoHHmHOHHou u HN .Oe u N I OO u EOOOOHH mo mOOHOOnH 104 OH.A OmO. OH.A ONH. OH.A OmO.I OH.A mHH. OH.A HeO.. OH.A OOO. OH.A OOO.I mO. 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