RELATEONQ'TBP’S OF POTASSIUM FIXATION AND RELEASE TO THE CLAY MINERAL COMPOSETTON OF fiOME MECHTGM S‘QiLS Thesis Eoc- ffie Degree of M. 5. MECHEGAN STME UMVERSETY Samuel L. Cummings 1959 LIBRARY Michigan State University RELATIONSHIPS OF POTASSIUM FIXATION AND RELEASE TO THE CLAY MINERAL COMPOSITION OF SOME MICHIGAN SOILS BY Samuel L. Cummings AN ABSTRACT Submitted to the College of Agriculture of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements ' for the degree of MASTER OF SCIENCE Department of Soil Science Year 1959 /n 1 q 2 2/ / 74W / Approved /449/ A14 ;;6E ’ fétuéx )7], Samuel Cummings ABSTRACT Some Michigan soils were studied to determine the re- lationships between potassium fixation and release to the clay mineral composition. The soils were selected from those of project 413 of the Michigan State Agricultural Experiment Station on the basis of the Michigan potassium soil test (0.13 N HCI extract). They ranged from 36 to 400 pounds of potassium per acre. Potassium fixation was determined in the laboratory by adding potassium as a KCl solution, drying at 110 degrees centlgrade, and extracting potassium with 0.5 N NH4CI solution. Potassium release was determined in the greenhouse by growing wheat plants in a small quantity of soil mixed with quartz sand for 26 days. The clay minerals were identified from X-ray diffrac- tion patterns. The nonexchangeable potassium released to the plants was significantly related to the exchangeable potassium, the water soluble potassium, the amount of clay, the amount of illite, and the amount of 2:1 expanding clay minerals. The Michigan soil test and the Woodruff soil test were not signi- ficantly related to the nonexchangeable potassium released to the plants. Potassium fixation was significantly related to the amount of clay and the 2:1 expanding clay minerals. There is a trend for the soils fixing the higher percentage of applied potassium to contain a larger quantity of 2:1 expanding clay minerals. In 26 out of 30 cases, the amount of potassium taken up by the plant exceeded the initially exchangeable potas- sium. Potassium uptake ranged from 69 to 1,950 pounds per acre. RELATIONSHIPS OF POTASSIUM FIXATION AND RELEASE TO THE CLAY MINERAL COMPOSITION OF SOME MICHIGAN SOILS By Samuel L. Cummings A THESIS Submitted to the College of Agriculture of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Soil Science Year 1959 ACKNOWLEDGMENTS The author wishes to express his sincere appreciation to Dr. M. M. Mortland under whose supervision this investi- gation was undertaken. He is indebted to Dr. K. Lawton for his interest in the investigation and his suggestions in improving the pre- sentation of materials. He is also indebted to Dr. R. L. Cook for guidance offered in his graduate study. The author also wishes to acknowledge his fellow graduate students of the Soil Science Department for their willing assistance in this project. ii TABLE OF CONTENTS INTRODUCTION. . . . . . . . . . . . REVIEW OF LITERATURE. . . . . . . . EXPERIMENTAL METHODS. . . . . . . . Soils. . . . . . . . . . . . Laboratory Investigation . . Potassium fixation. . . Water soluble potassium Woodruff soil test. . . Greenhouse Experiment. . . . ANALYTICAL METHODS. . . . . . . . . Clay Fractionation . . . . . Total Potassium in the Clay Fraction Specific Surface . . . . . . Xaray Diffraction. . . . . . DISCUSSION OF RESULTS . . . . . . . Potassium Release. . . . . . Potassium Fixation . . . . . Clay Minerals. . . . . . . . GENERAL DISCUSSION. . . . . . . . . SUMMARY . . . . . . . . . . . . . . LITERATURE CITED. . . . . . . . . . APPENDIX. . . . . . . . . . . . . . X-ray Diffraction Patterns . iii PAGE \0 \OCDO) (I) 03 (I) U "‘ —b d c-h d 11 12 13 14 14 27 30 37 4O 41 44 49 LIST OF TABLES Table Page 1. Soil type and number, horizon,Michigan soil test, release of nonexchangeable potassium, exchange- able potassium, water soluble potassium, Woodruff soil test, applied potassium fixed, percent clay, and specific surface. . . . . . . . . . . . . . . 15 2. Linear correlation coefficients . . . . . . . . . l9 3. Clay minerals . . . . . . . . . . . . . . . . . . 32 4. Quantitative estimation of the clay minerals. . . 45 5. AI, plant weight, total otassium, potassium in plants, and plant K/JCa+M. iv LIST OF FIGURES Nonexchangeable potassium released to plants ver- sus the percent C|ay0 O O O O O O O O O O O O O O Nonexchangeable potassium released to plants versus total potassium in the clay times the per- cent C‘ay O O O O I O O O O 0 O O O O O O O O O O Nonexchangeable potassium released to plants ver- sus the Michigan soil test. . . . . . . . . . . . Nonexchangeable potassium released to plants ver- sus the exchangeable potassium. . . . . . . . . . Percent of applied potassium fixed versus AI times the percent clay. . . . . . . . . . . . . . Page 21 22 23 24 29 INTRODUCTION Potassium is one of the most soluble elements in the form of the simpler chemical compounds, but in the soil-plant system it is characterized by wide variations in solubility and mobility. Soil potassium ranges from the soluble state through a range of decreasing activity to the state of an essential constituent of certain primary minerals from which it is released only by destruction of the crystal structure. Potassium is found in the soil in the form of primary and secondary minerals. In soils that are strongly weathered, feldspars and micas ordinarily are the most abundant of the potassium-bearing minerals. The most important of these for supplying potassium are orthoclase and microcline feld- spars, biotite and muscovite mica, and illite. The feldspars occur almost exclusively in the sand and silt fractions of soils but are found occasionally in the coarse clay. Bio- . tite and muscovite occur mainly in the silt and sand fractions. Illlte, the main potassiumabearing mineral of the clay frac- tion, is micaceous in nature, and is usually of secondary origin. The predominate clay minerals (secondary minerals) include the montmorillonite series, illites or hydrous micas, vermiculite, chlorite, kaolinite, and interstratified minerals in which two or more of the preceding types occur in more or less random arrangement within the same particle. In many soils the entire range of known forms of potassium occurs; in other soils some forms may be lacking, usually because of the absence of some types of primary or clay minerals. The order of relative resistance to weathering of these soil minerals is kaolinite, montmorillonite, vermicu- lite, and'interstratified 2:1 layer silicates, muscovite and illite, orthoclase and microcline feldspars, and biotite and chlorite. The ability of a given soil to supply potassium to crOps is a result of many processes which must be studied and evaluated for a proper understanding of potassium avail- ability. The clay fraction of soils is involved in many physio- chemical reactions which are important in the development of soils and in their functioning as a medium for plant growth. The active minerals of clays undergo changes upon contact with water, soil amendments, excretory and secretory products of organisms, or with soluble substances released from weathered minerals and decaying organic matter. Other changes in these minerals occur when water and nutrient elements are removed from them. The many reactions and changes which clays under- go, because of their colloidal nature, have led Kelly (l5) to designate the clays as the active fraction of the soil. The objective of this investigation was to relate potassium release and fixation to the clay mineral composition of some Michigan soils. REVIEW OF LITERATURE The release and fixation of potassium in soils has been recognized for many years, but unanswered problems remain which deal with the interaction of the clay minerals. The proportion of the total potassium held in the water soluble, and exchangeable forms usually is relatively small. The majority of it resides in potassium-bearing primary and clay minerals. The distinction between the soluble potassium and other forms is arbitrary. Reitemeier (20) has shown that by dilu— tion with water, the soluble potassium will increase, because of hydrolysis of exchangeable potassium. Soluble potassium may also be increased by the replacement of exchangeable potassium by divalent ions or dissolution of potassium-bear- ing minerals. Reitemeier (21) stated that the amount of soluble potassium present at any one time, even in fertile soils, is inadequate to meet the major part of the requirements of crops. Apart from the concept of contact feeding by roots on exchangeable cations, as presented by Jenny and Overstreet (12), it is presumed that all potassium entering roots must be in the soluble form. However, the replenishment of solu- ble potassium may occur rapidly enough directly from the ex- changeable form and indirectly from the nonexchangeable form to satisfy plant demands. Although recognizing the importance of this soluble-exchangeableequilibrium, York (27) concluded that 3 the controlling factor in potassium absorption is the avail- able supply in the soil solution.. Usually, the degree of saturation of cation exchange complex of the soil by potassium is small, yet the avail- ability of the exchangeable potassium is relatively high. Jarusov (10) has presented the case of the mobilities of two cations possessing different energies of absorption, and pre- sent in varying proportions in the complex. For example, the strength of the bond of one cation with the complex (the one with a higher energy of absorption) decreases as the complex becomes more saturated with this cation, and consequently its mobility increases. For the cation having the lower absorp- tion energy, the mobility changes relatively little as the complex becomes inceeaslngly saturated with this cation. Woodruff (26) using water extracts, expressed activities of potassium and calcium in concentration units (moles per liter) and calculated the energy of exchange, which is a measure of the intensity factor in the delivery of a balanced supply of nutrient cations from the exchange complex of the soil to the growing plant. He found the energies of exchange for the replacement of calcium with potassium to range from -3,500 to -4,000 calories were associated with potassium deficiencies in plants. Energies of exchange from -2,500 to -3,000 calories represented suitable balances between potassium and calcium. Energies of exchange of -2,0a)calories or less were associ- ated with escessive amounts of potassium in relation to the amounts of calcium that were present. Wiklander (24) reported that the ease of release of an ion depends not only on the nature of the ion itself, but also upon the nature of the complementary ions filling the remainder of the exchange positions and the degree to which the replaced ion saturates the exchange complex. Jenny and Ayers (11) found the availability of potassium to plants, especially at lower levels of potassium satura- tion, was greater when calcium rather than hydrogen, was the complementary ion. Barber and Marshall (3) have shown that illite tends to hold potassium more tenaciously and calcium less tena- ciously, than montmorillonite. Work by Mortland, Lawton, and Uehara (18) indicatesa comparatively rapid release to plants of the potassium fixed by montmorillonite and vermi- culite and of native potassium of biotite. In this study the release of potassium from illite and muscovite was of much lower magnitude. There have been numerous reports dealing with potas- sium fixation in soils in recent years and its relationship to the type of clay minerals present. Seatz and Winters (22) working with soils which developed on material residual from argillaceous limestone, found that fixation tended to be greater in soils that contained the highest proportion of mica and montmorillonite types of clay mineral. Joffe and Levine (14) and Stanford (23) have shown that potassium fixa- tion occurs in the fine clay fraction of 2:1 type clay miner- als. In addition, Hoover (9), and Raney and Hoover (19) reported that montmorillonitic soils fix more potassium than kaolinitlc soils. Wiklander and Gieseking (25) showed montmorillonitic clays and illitic clays to be more effec- tive in potassium fixation than kaolinitlc clays. In studies with illite and vermiculite as single minerals, DeMumbrum and Hoover (7) found that whereas illite did not fix any applied potassium, vermiculite fixed large amounts. Kunze and Jeffries (16) X-rayed the soil-clays of 15 soils classified as representative of the Gray-Brown Podzolic group which were potassium saturated and magnesium saturated. They found the soil-clays giving a strong i0 angstrom line in the x-ray diffraction pattern when potassium saturated I as contrasted to a strong 14 aggstrom line when magnesium a saturated were relatively high fixers of potassium. Those soil-clays which showed little or no shifting of the larger basal spacings toward 10 angstroms when saturated with potas- sium were found to be relatively low fixers of potassium. In 1924 Ames and Simon (1) reported that water soluble potassium determined after heating the soil to 100, 400, or 700 degrees centigrade was greatly increased with temperature. Joffe and Kolodny (13) found the release of potassium from Dover loam to be greatly increased by temperatures up to 600 degrees centigrade. It was pointed out by Bray and DeTurk (6) that heating at 200 degrees centigrade may result in either the release or fixation of potassium depending on the equili- brium conditions at the beginning of the heat treatments. 7 Attoe (2) was the first to establish that potassium was re- leased to the exchangeable form by soils upon drying and re- verted to the nonexchangeable form upon remoistening. If excess potassium was present in the system, fixation occured as a result of drying. Luebs, Stanford, and Scott (17) studied the effect of moisture upon exchangeable potassium and confirmed Attoe's results. Hanway, Scott, and Stanford (8) have found that a 350 degree centigrade temperature is necessary to fix rela- tive small amounts of potassium in montmorillonite. Even smaller amounts of potassium were fixed at lower temperatures in montmorillonites studied by Barshad (4), who postulated that any fixation was caused by a few highly charged (vermi- culite-like) layers present in the montmorillonite as a very minor constituent, presumably as an interstratified material. EXPERIMENTAL METHODS Soils The soils used in the investigation were chosen from project 413 of the Michigan State University Agricultural Experiment Station on the basis of the potassium extracted by the rapid soil (0.13 N HCI) test used in making fertilizer recommendations in Michigan. The values for potassium thus removed ranged from 36 pounds per acre to 400 pounds per acre of potassium as shown in Table 1. This test is pur- ported to remove all water soluble and a high percentage of the exchangeable potassium from the soil. Laboratory Investigations Potassium fixation. The potassium fixing capacity was determined by weighing 5 grams of soil into a beaker and added 5 milliliters of 0.005 N KCl plus 50 milliliters of distilled water. Duplicate samples were placed in a 110 degree centigrade oven and dried over night. They were re- moved from the oven and allowed to stand two hours in con- tact with 50 milliliters of 0.5 N NH4Cl. Then they were filtered and washed with 50 milliliters more of the 0.5 N NH4CI. Potassium was determined in the filtrate using a Perkin-Elmer Model 52A flame photometer. Water soluble potassium. Water soluble potassium was determined by weighing 100 grams of soil into a buchner 8 funnel, saturated with distilled water, and allowed to stand over night. Twenty-five milliliters of distilled water were added and the solution removed from the soil by suction. Potassium was determined with a Beckman D. U. flame photo- meter. Woodruff soil test. Five grams of soil was placed in a 3 ounce bottle containing 1% milliliters of distilled water and allowed to stand over night. Then 30 milliliters of 0.01 M CaCl2 was added and gently shaken four times at 15 minute intervals and filtered after one hour. Potassium was determined with the Perkin-Elmer Model 52A flame photo- meter. Greenhouse Experiment To determine the release of soil potassium on cropping, wheat plants were grown in a limited amount of soil. The media for plant growth was prepared by mixing 200 grams of silica sand with 25 grams of soil and placing the mixture in a 16 ounce cottage cheese carton. Four hundred grams of silica sand were placed on top of the mixture of silica sand and soil. There were 2 replications for each soil used. Six- teen wheat seeds were planted and the media moistened with dis- tilled water. Each culture was thinned to 10 plants after emergence. After the cultures were thinned, 15 milligrams of nitrogen was added as a water solution of ammonium nitrate over a period of two weeks. The wheat plants were allowed to lO grow until it appeared that the rate of growth had markedly decreased. The period was found to be 26 days. The plants (tops and roots) were ground with a Wiley mill and approximately 0.5 grams weighed into a 250 milli- liter beaker. Ten milliliters of concentrated HNO3 was thoroughly mixed with the sample and digested on a hot plate until all the fiberous material was in solution. Ten milli- liters of distilled water and 10 milliliters of HCl04 were added and digestion continued at a moderate temperature. The solution was evaporated to dryness and the residue re- moved with 0.1 N HCl. This solution was filtered into a 100 milliliter volumetric flask, and potassium was determined using a Beckman D.U. flame photometer. Calcium and magnesium were determined by the Versenate method outlined in USDA Handbook 60. ANALYTICAL METHODS Clay Fractionation The clay was removed by placing 10 grams of soil in a 600 milliliter beaker, and adding 100 milliliters of 6 percent H202 and a few drops of acetic acid. After stand- ing over night they were heated on a hot plate, followed by 50 milliliters of 30 percent H202 and again heated. One hundred milliliters of 0.1 N HCI was added and the soil de- posited on a number 50 Whatman filter paper. Three additional HCI washes were used, followed by distilled water until free of chlorides. Each sample was transferred to a shaker bottle and titrated with 0.1 N NaOH. Following 24 hours of shaking each sample was transferred to a sedimentation cylinder, filled with distilled water and set in a constant temperature bath. After the suspension temperature was equal to the bath temperature the suspensions were thoroughly mixed and the clay fraction extracted at the appropriate time and depth. The clay suspension was concentrated by drying in an oven at 110 degrees centigrade. Total Potassium in the Clay Fraction Total potassium was determined by weighing approxi- mately 0.5 grams of clay into a platinum crucible. The sam- ple was heated and one milliliter of H2804 (1:5) added. Five milliliters of concentrated HF was added and evaporated to 11 12 dryness. An additional 5 milliliters of HF was added and evaporated to dryness. The residue was removed by placing the crucible in a beaker containing HN03 (1:20) and heating. The crucible was removed and rinsed three times with dis- tilled water. If any of the residue remained, it was re- moved with a rubber policeman. The resulting solution was evaporated to dryness and taken up with 0.1 N HCI. The solu- tion was filtered into a 100 milliliter volumetric flask. Potassium was determined with a Beckman D.U. flame photometer. Only one sample of each clay was analyzed, since the supply was limited. However, previous work with this method of analysis has shown high precision. Specific Surface The specific surface of each clay fraction was de- termined by using a modified Bower and Gschwend (5) proce- dure. First 0.3-0.5 grams of air dried clay was weighed into tared weighing bottles. Single samples of each clay fraction were placed in a vacuum desslcator over P205 and evacuated to a constant weight. Twenty drops of ethylene glycol were added to each sample, distributing it over the entire sample and allowing it to stand over night to get uniform wetting. The clay samples were then evacuated over CaCl2 until they began to assume a dry appearance. They were weighed and evacuated again and reweighed at one hour intervals until the weights remained comparatively constant. 13 X-ray Diffraction A small amount of clay suspension was placed in a test tube and a few drops of glycerol added. After stand- ing over night the clay was deposited on a porous plate and washed with three increments of 0.1 N CaCl2 which was 3 percent glycerol by volume. The deposit was allowed to air dry and then placed in a desslcator over CaClg. The sample was X-rayed as a calcium saturated, glycerol sol- vated, oriented aggregate using a Norelco diffraction unit with copper radiation and a nickel filter. After the initial x-ray eXposure the calcium saturated, glycerol solvated, oriented aggregate was saturated with potassium by leach- ing with 0.1 N KCl, and the excess KCl washed out with dis- tilled water. The sample was then heated to 110 degrees centigrade and X-rayed. This was followed by a heat treat- ment to 550 degrees centigrade and a third X-ray exposure. DISCUSSION OF RESULTS Potassium Release The data in Table 1 include several chemical character- izations of potassium from the clays, as well as the order and amount of potassium released to plants during a 26 day period. In general, the clay and loam soils released more potassium than the sandy soils, although there are a few exceptions which would include samples 24, 142, 159, and 55. A good exampleEWe soils number 337 and 157. Number 337 with 11.5 percent clay released a little more potassium than did number 157 with 67.5 percent clay. Number 30 with 22.6 percent clay released the largest amount of potassium, while many of the other soils contained a higher percentage of clay. These com- parisons are presented graphically in Figure 1. Statistical analysis indicates that the percentage clay mineral composition is a factor regulating the rate of release of potassium to the plant. These analyses are pre- sented in Table 2. The percent illite in the clay fraction was signifi- cantly correlated with the potassium released to the plants. This value for illite is given in Table 2 as total potassium in the clay fractions times the percent clay. The assump- tion was made that all of the potassium in the clay fraction was in the illite structure. Figure II graphically repre- sents these data. 14 15 TABLE 1. SOIL TYPE AND NUMBER, HORIZON,MICHIGAN SOIL TEST, RELEASE OF NONEXCHANGEABLE POTASSIUM, EXCHANGE- ABLE POTASSIUM, WATER SOLUBLE POTASSIUM, WOOD- RUFF SOIL TEST, APPLIED POTASSIUM FIXED, PERCENT CLAY, AND SPECIFIC SURFACE OF CLAY Sample Michigan Number Soil Type Horizon Spil Test (lbs K/acre) 30 Brookston loam A._2 276 180 Ontonagon silty Clay AD 192 158 Paulding clay C 232 185 Selkirk clay C 56 108 Conover sandy loam C 184 192 Selkirk clay loam c 40 337 Iron River silt AD 292 157 Paulding clay C 156 21 Miami sandy loam B 104 146 Coldwater sandy clay loam Ap 245 126 Miami sandy loam C 64 42 Paulding clay C 224 24 Brookston sandy loam A. 212 142 Mancelona sand B, 312 107 Conover loam 82 138 18 Miami sandy loam A. 72 25 Brookston sandy loam B; 120 166 Coldwater sandy loam 82 264 27 Brookston sandy loam 82 156 Water Woodruff Applied Percent 16 Release Exchange- Specific $122312; (Tgsl/zcée) TfiurfiégrEfig‘lJaecsfe) K(;)xed Clay 81273-758 K (lbs/acre) (M2/ m 1,481 469 44 366 56 22.6 133 847 383 11 210 30 41.0 94 776 492 3 47 92 70.3 139 52l 312 3 68 48 60.7 160 478 148' 4 47 74 l6.5 167 328 141 1 31 42 32.3 112 327 148 11 227 1 11.5 294 303 607 4 72 84 67.2 125 273 148 3 43 54 19.5 142 235 125 9 135 44 25.0 138 233 62 2 50 56 10.7 104 210 312 4 93 36 41.9 139 197 102 8 92 42 12.2 215 158 109 I7 175 -6 2.9 242 157 203 2 35 84 23.6 146 149 86 4 67 40 8.9 190 146 55 2 35 62 11.0 339 119 125 2 47 68 18.8 155 108 125 2 47 74 15.0 147 17 TABLE 1 (CONTINUED) W Sample Michigan Number Soil Type Horizon Soil Test (lbs K/acre) 141 Mancelona sand Ap 196 11 Spinks sandy loam Al 82 159 Brookston clay loam Ap 168 8 Granby sand 829 36 63 Spinks sand A 144 52 Fox sand C. 90 55 Warsaw loam 8| 280 71 Warsaw sand B. 112 395 Munising loam C 340 205 Saugatuck sand A2 400 349 Mariensco sandy loam Bp 312 M *Potassium in the plant (per acre) minus the exchangeable potassium. 18 l Release Exdnange- Water Woodruff Applied Percent Specific of Nonex- able K Soluble K Soil Test K Fixed Clay Surface Snag/afltee: (lbs/acre) (lbs/acre) (lbs K/acre) (%) 23221323 ' 87 187 £22 234 ’ 15 3.1 230 86 78 7 67 36 7.5 170 80 352 3 52 72 35.2 184 73 39 4 67 10 2.4 284 72 109 8 131 24 5.2 270 19 7O 5 67 20 1.9 333 16 258 9 217 -2 25.6 466 -9 78 7 111 1D 4.0 390 -16 125 4 128 36 9.5 173 -33 133 17 161 4 3.4 276 -99 234 10 256 14 4.0 295 19 .TABLE 2 LINEAR CORRELATION COEFFICIENTS Elnear Correlation Correlation Coefficient Nonexchangeable K released to plants versus total K in clay times percent clay .511** Nonexchangeable K released to plants versus AI+ times percent clay .447* Nonexchangeable K released to plants versus exchangeable K .602** Nonexchangeable K released to plants versus Michigan soil test .347 Nonexchangeable K released to plants versus Woodruff soil test .342 Nonexchangeable K released to plants versus water soluble K .521** Nonexchangeable K released to plants versus plant K .652** a+ g Nonexchangeable K released to plants versus plant weight ,754es Nonexchangeable K released to plants versus percent clay .486** Applied K fixed versus AI+ times percent clay .401* Applied K fixed versus percent vermiculite times percent clay .359 Applied K fixed versus nonexchangeable K released to plants .350 Applied K fixed versus specific surface times percent clay .363* Michigan soil test versus total K in clay times percent clay -.104 20 TABLE 2 (CONTINUED) Linear Correlation Correlation Coefficient Michigan soil test versus plant weight -.O79 Michigan soil test versus plant K .250 a+ 9 Michigan soil test versus the total K taken up by plants .819** Water soluble K versus total K times percent clay -.228 Water soluble K versus specific surface times percent clay -.228 *WM— —-——_.—.-——_- **1 percent significance. *5 percent significance. +AJ is the change in intensity of the 10 angstrom peak of the X-ray diffraction patterns, going from a calcium saturated, glycerol solvated clay sample to a potassium saturated clay sample heated to 110 degrees centigrade. 21 Umu<\.mm.: mhz mhz<4a o... oumquum 2:.mm4kom w40440 hzmummn. mus—C >440 m1» 2. 1v! 22348.". 430» mama: 324.6 0» 893.6: 1233.8 ”393024205262 : manor. . 400. TOTAL POTASSIUM TIMES PERCENT CLAY 23 Umo<\.mm.: whz th wbz<4m 100w 0.. owm_ manor. . EXCHANGEABLE POTASSIUM (LBS/ACRE) 25 The amountsof 2:1 expanding clay minerals were signi- ficantly correlated with the potassium released to the plants. This clay value is given in Table 2 as AI times the percent clay. Referring to the X-ray diffraction patterns, AI is the change In intensity of the 10 angstrom peak going from a cal- cium saturated, glycerol solvated clay sample to a clay sample which had been potassium saturated and heated to 110 degrees centigrade. This increase in intensity is a result of the collapsing of the 2:1 expanding clay minerals, namely vermi- culite and/or montmorillonite. The correlation between the Michigan soil test and the release of nonexchangeable potassium to the plants was not significant. Figure 111 graphically represents this comparison. Many of the soils with rather low Michigan soil test values gave higher amounts of available potassium* than soils testing higher by the Michigan soil test. A good example of this comparison is sampkm number- 30 and 337. Soil number 30 with a Michigan soil test value of 276 pounds of potassium per acre supplied the plants with 1,950 pounds of potassium per acre, while number 337 with a Michigan soil test value of 292 pounds of potassium per acre supplied only 475 pounds of potassium per acre to the plants. The poor correlation is probably due to the inability of the 0.13 N HCI *Nonexchangeable potassium plus exchangeable potas- sium. 26 to extract proportional amounts of potassium under different situations. The amount and kind of clay minerals and the different degree of saturation of other cations possibly affect the results obtained by this method. It is interest- ing to note that the nonexchangeable potassium released to plants was significantly correlated with the total potas- sium in the clay times the percent clay and with the dry plant weight. In contrast the Michigan soil test was not significantly correlated with either of these two factors. It would appear that a greater stress on the potassium equil- ibrium might be desireable. Plants are known to grow better where the K/i/EEIME ratio in the plant is within a certain range for the parti- cular species. This condition is brought about by the interaction of these elements. The fact that a significant correlation was obtained between this ratio and the release of nonexchangeable potassium to the plants suggests the im- portance of the contribution of this form of potassium to nutrient balance in the plant. The Woodruff soil test was also not sighificantly correlated with the nonexchangeable potassium released to plants. This test gave a correlation almost the same as the Michigan soil test, but the amounts of potassium ex- tracted from a given soil were generally quite different. The quantity of exchangeable potassium in the cjays: was significantly correlated with the amount of nonexchange- able potassium released to the plants. Figure IV graphically 1 , . ‘ , I r - a ' ," ‘. l » u a e x 1 I I . . . ,‘ ‘ . . . TV 1 i 1 u . ~ . , 1 u . . , . l (A . l . 27 represents this comparison. The quantity of potassium thus released exceeded the value for exbhangeable potassium in 26 of the 30 soils. 0f the four soils which didn't fit this situation, three gave the tOp three Michigan soil test values for this group of sells. With the majority of the potassium taken up by the plants coming directly or indirectly from the exchangeable positions, it would appear that the equilibrium between exchangeable and nonexchangeable potassium is very important in determining the amount of potassium available to the plant. The amount of potassium in the exchangeable and nonexchangeable positions and the type of chemical bind— ing may be controlling factors imposed on this equilibrium. The water soluble potassium was significantly corre- lated with the nonexchangeable potassium released to the plants, but the values for the water soluble potassium are very low as compared with the potassium released from the majority of the soils. 'The quantity of water soluble potassium depends in large part on an equilibrium condition with the exchangeable potassium. This equilibrium in turn depends on the exchange- able-nonexchangeable equilibrium. Potassium Fixation The data in Table 1 show that a wide range of fixa- tion of soluble potassium occured within the 30 soils studied. With soils number 55 and 142, Warsaw loam and Mancelona sand respectively, a small amount of potassium was actually re- leased at this level of application. 28 With the exception of 3 of the soils, all of the clay and loam soils fixed 30 percent or more, while the sandy soils fixed less than 30 percent of the applied potas- sium. These trends indicate that the amount of clay is a factor in potassium fixation. Correlation coefficients given in Table 2 show that the amountsof 2:1 expanding clay minerals were significantly correlated with the Potassium fixed, but the percent vermi- culite as estimated by the method described in Table 4 was not significantly correlated with the potassium fixed. Fig- ure V graphically represents the percent potassium fixed ver- sus the 2:1 expanding clay minerals. On this basis it could be concluded that montmorillonite is the principle clay min- eral responsible for the fixation of potassium. However, this conclusion should be avoided, because the method for the quantitative estimation of the relative amounts of vermi- culite and montmorillonite may introduce enough error to make this invalid. There was no significant correlation between the amount of potassium fixed and the quantity of potassium re- leased from the soil. However, there was a trend for some of the soils which fixed large amounts of potassium to re- lease large quantities of this ion. This relationship sup- ports the correlation of the amount of 2:1 expanding clay minerals with the potassium released on cropping. Therefore 29 002». >440 pzuomua mmzr» .0 2.3: 33. 23.0. coma 056 com... 3...». o — d i .4 u 1 J u u 4 q —0 u — W le 0 0 e. O. . IV» 0 000g 0 e l¢0 0 I e I . :12. 2:65 :3 ezmomma 3:: .q m2m¢u> Iva 3x... 22330.. 33...: pzuomua > 23o: PERCENT APPLIED POTASSIUM FIXED 29 000.: 2.5 ezuomua $2.» .0 03.! 00.3. owed. com.» 956 com... 33 o — a d u A q - q d 1 q — q — 1 1m... 0 O 0 c. 0. Ion 0 v . u o L . Ice. 0 o O o eeJVb e e 4 ETC! :6 pzuomua 3:.» .q m3m¢u> Iva aux... 22348.. $3.54 ezmocua > menu: PERCENT APPLIED POTASSIUM FIXED 30 it would appear that the 2:1 expanding clay minerals partially control the release of potassium as well as being the princi- ple clay minerals associated with the fixation of potassium. Upon comparing potassium fixation with the X-ray dif- fraction patterns (appendix), there is a trend for the higher potassium-fixing clays to have a more intense 10 angstrom peak when they are potassium saturated and heated to 550 degrees centigrade. Clay Minerals In Table 3 the discrete and interstratified clay minerals of each soil clay fraction are listed. These data were obtained from the X-ray patterns given in the appendix. Discrete Illite and quartz were identified in all of the soil clay fractions. Illite was identified by the pre- sence of a 10 angstrom peak with the calcium saturated, glycerol solvated clay sample. Quartz was identified by the occurence of a 4.26 angstrom peak. Mm..- ow" Discrete kaolinite was identified in all of the soil clay fractions except soil number 205. The criteria for the presence of kaolinite was the disappearance of the 7 and 3.5 angstrom peaks when the Clay sample was potassium saturated and heated to 550 degrees centigrade. Vermicullte was found randomly interstratified in all but one of the soil clays as a vermiculite-chlorite interstratification or a vermiculite-chlorite-montmorillonite 31 interstratification. Discrete vermiculite was noted in only 12 of the soil clays. Identification of this soil clay min- eral was accomplished by noting the disappearance of or a decrease in the 14 angstrom peak on comparing a calcium saturated, glycerol solvated clay sample with a potassium saturated clay heated to 110 degrees centigrade. The ran- domly interstratified vermiculite-chlorite clay minerals were identified by first observing, for example, a 14 angstrom peak when the claysmmle was calcium saturated, glycerol sol- vated and then observing if a broad peak occurred between 10 and 14 angstroms after potassium saturating and heating the Clay sample. If a broad series of peaks occurred be- tween 10 and 14 angstroms, vermiculite and chlorite were said to be randomly interstratified. Relative amounts of chlorite or vermiculite may be estimated by the position of the broad peak relative to the 10 and 14 angstrom position. Discrete chlorite was found in 20 of the soil clays and appeared in randomly interstratified systems in all sam- ples except one. The clay mineral, chlorite was identified by the persistence of a 14 angstrom peak after potassium saturation and heating to 110 degrees centigrade. X-ray data indicate discrete chlorite present in 72 percent of the loamy soil Clays, in 60 percent of the clayey soil clays, and in 57 percent of the sandy soil clays. Forty-four per- cent of the soils classed as loamy soils bordered on the 32 TABLE 3 CLAY MINERALS Sample Number Soil Type Discrete Interstratified 158 Paulding clay I K Q v_c 42 Paulding clay I K Q V-C 52 Fox sand I K Q V-C-M 30 Brookston loam I K Q V-M-C 8 Granby sand I K Q C C-V 18 Miami sandy loam I K Q C V-C 63 Spinks sand I K Q C V-C-M 55 Warsaw loam I K Q C V-C-M 166 Coldwater sandy I K Q M V-C loam 159 Brookston clay I K Q M V-C loam 25 Brookston sandy I K Q M V-C loam 7i Warsaw sand I K Q M V-C 349 Mariensco sandy I K Q M C C-V loam 27 Brookston sandy I K Q M C V-C loam 21 Miami sandy loam I K Q V C V-C 180 Ontonagon silty I K Q V C v-C clay 157 Paulding clay I K Q V C V-c 33 TABLE 3 (CONTINUED) Sample Number Soil Type Discrete Interstratified 337 Iron River silt I K Q V C V-C-M 185 Selkirk clay I K Q V C C-M-v 107 Conover loam I K Q V C V-C-M 146 Coldwater sandy I K Q V C M V-C clay loam 192 Selkirk clay loam I K Q V C M V-C 11 Spinks sandy loam I K Q V C M V-C 108 Conover sandy loam I K Q V C M V-C 395 Munising loam I K Q V C M V-C 126 Miami sandy loam I K Q V-M 24 Brookston sandy loam I K Q C M C-M 205 Saugatuck sand I Q C F V-C 142 Mancelona sand I K Q F C C-V 141 Mancelona sand I K Q F C C-V Legend: I=Illite K:Kaolinite Q=Quartz C:Chlorite MzMontmorillonite V=Vermiculite F=Feldspars 34 sandy side, this grouping suggests that a higher percentage of the sandy soils contained discrete chlorite. Discrete montmorillonite was noted in 12 of the soil clays and as a randomly interstratified clay mineral in 10 other samples. It was found that fifty-five percent of the loamy soil clays and 14 percent of the sandy soil clays con- tained discrete montmorillonite. It is interesting that none of the clayey soil clays contained discrete montmorillonite. Criteria for the presence of discrete montmorillonite was the occurence of a 17.7 angstrom peak when the soil clays were calcium saturated, glycerol solvated. Feldspars were identified by the persistence of a 3.25 angstrom peak- in three of the clay fractions separated from soils which were of a sandy texture. Several of the soils have the same type of discrete and interstratified clay minerals but the amounts of each type and degree of interstratification varies with each soil. Table 3 shows 14 different assortments of the clay minerals. Nine of the assortments are represented by two to four soils and five are represented by only one soil. The variability and complexity of these clay mineral sys- tems makes a comparison of the clay mineral composition with the release of nonexchangeable potassium and fixation of potassium quite difficult. Soils number 258 and 42 containing the same type of clay minerals and the same type of interstratification had 35 very similar X-ray diffraction patterns, with 158 having the more intense peaks. Soil number 42 with 41.9 percent clay released only 27 percent as much nonexchangeable potas- sium as did soil number 158 with 70.3 percent clay. These data suggest that the amount of the different clay minerals is a factor helping to regulate the release of nonexchange- able potassium. More potassium was fixed by soil number 158 than by soil number 42, a condition which was again possibly related to the amounts of the different kinds of clay min- erals. 'The same general pattern of fixation and release that was evident in these two soils, was also found for soils number 52 and 30, 8 and 18, and 349 and 27. It is apparent that the soil with the more intense X-ray diffrac- tion pattern peaks containing the highest percentage of clay, released the most nonexchangeable potassium and fixed the most applied potassium. In these particular soils the total amount of clay may have been more important in controlling fixation and release of potassium from the soil clays than the particular type of clay mineral. The remainder of the soils do not show this same con- formity and consequently no adequate comparison of these soil clay minerals with the release of nonexchangeable potas- sium and fixation of added potassium can be made using the Xaray diffraction patterns. By comparing the potassium re- leased and fixation data with the amount of clay in each soil 36 of these different assortments, it appears that the amount of certain type of clay minerals, probably 2:1 expanding minerals, are more important than the total amount of clay. GENERAL DISCUSSION The complexity of the clay minerals found in the soils and the present methods of making quantitative estima- tion of clay minerals does not allow an adequate comparison of the clay mineral composition with the release of nonex- changeable potassium and potassium fixation. Although rather general statements can be made concerning clay mineral com- position and the release of nonexchangeable and fixed potas- sium, it is difficult to state exactly what the difference is between two particular soils. A good example of this can be seen in a comparison of data of soils number 180 and 55. Soil number 180 with a specific surface of 94 square meters per gram, with 41 percent clay, of which 50 percent was illite, contained vermiculite and no montmorillonite. This soil clay released 847 pounds of nonexchangeable potassium per acre, while soil number 55 with a specific surface of 466 square meters per gram, with 25.6 percent clay of which 25 percent was illite, contained vermiculite and montmorillonite. Release of nonexchangeable potassium from this soil clay amounted to only 16 pounds per acre. These values for potas- sium release seem to be correct assuming all the potassium is in the illite clay mineral. The picture of potassium fixation becomes somewhat more complicated, since soil num- ber 180 fixed 30 percent of the applied potassium while soil number 55 released potassium at this particular rate of appli- cation. It would appear that soil number 55 should fix the 37 38 most potassium due to the presence of montmorillonite and vermiculite. In addition this soil clay had a specific surface approximately 4.5 times larger than soil number 180. This high specific surface indicates that approxi- mately 50 percent of the clay minerals are probably present as 2:1 expanding clay minerals. As previously mentioned such clawsare considered to be the main fixers of potassium. The fact that the clay from soil number 55 has interstratified vermiculite and montmorillonite and vermiculite with no dis- crete vermiculite or montmorillonite, while clay from soil num- ber 180 contains discrete vermiculite as well as interstrati- fied vermiculite may have an effect on the fixing properties of the two clay systems. Actually there is no experimental evidence to verify this conclusion. The correlation between the relative amounts of 2:1 expanding clay minerals times the percent clay versus the non- exchangeable potassium released to the plants is very interest- ing, as one would expect an inverse rather than a direct re- lationship. The positive correlation may indicate that some of the initially nonexchangeable potassium may occur in the expanded 2:1 minerals and that it may be an oversimplifica- tion to allocatezui nonexchangeable potassium to 10 angstrom layers. The release of nonexchangeable potassium to the plants was positively correlated with the amount of illite clay 39 mineral, the exchangeable potassium, and the water soluble potassium, but none of these give a very good estimation of the amount of available potassium to the plants. It is concluded that a better understanding of the water soluble-exchangeable-nonexchangeable equilibrium of each soil is very important in interpreting the release of potassium to the plants. 1. SUMMARY The following factors are related to the release of nonexchangeable potassium to the plants: A. The amount of clay in the soil. 8. The types of clay minerals. a. Illite mineral. b. 2:1 expanding minerals. C. The exchangeable potassium. D. The water soluble potassium. The following factors affect the fixation of potassium: A. The amount of clay in the soil. 8. The 2:1 expanding clay minerals. There is a trend for the higher fixers of potassium to have a more intense 10 angstrom X-ray diffraction peak when potassium saturated and heated to 550 degrees centi- grade. In most of the cases, the amount of potassium taken up by the plants exceeded the exchangeable potassium. The Michigan soil test and the Woodruff soil test did not give significant correlatiOns with the release of nonex- changeable potassion to plants. 40 10. 11. 12. LITERATURE CITED Ames, J. W. and Simon, R. H. Soil potassium as affected by fertilizer treatment and crOpping. Ohio Agr. Exp. Sta. Bull. 379. 1924. Attoe, O. J. Potassium fixation and release in soils occuring under moist and drying conditions. Soil Sci. Soc. Amer. Proc. 3:101-106. 1947. Barber, S. A. and Marshall, C. E. Ionization of soils and soil colloids: III. Potassium-calcium relation- ship in illite, kaolinite, and halloysite. Soil Sci. 73:403-413. 1952. Barshad, I. Cation exchange in micae minerals: 1. Re- placeability of interlayer cations of vermiculite with ammonium and potassium ions. Soil Sci. 77:463-472. 1952. Bower, C. A. and Gschwend, F. B. Ethylene glycol re- tention by soils as a measure of surface area and interlayer swelling. Soil Sci. Soc. Amer. Proc. 16:342-345. 1952. Bray, R. H. and DeTurk, E. E. The release of potassium from nonexchangeable forms in Illinois soils. Soil Sci. Soc. Amer. Proc. 3:101-106. 1939. DeMumbrum, L. E. and Hoover, C. 0. Potassium release and fixation related to illite and vermiculite as single minerals and in mixtures. Soil Sci. Soc. Amer. Proc. 22:222-225. 1958. Hanway, H., Scott, A. 0., and Stanford, G. Replaceability of ammonium fixed in clay minerals as influenced by NH4 or K in the extracting solution. Soil Sci. Soc. Amer. Proc. 21:29-34. 1957. Hoover, C. D. The fixation of potash by a kaolinitlc and a montmorillonitic soil. Soil Sci. Soc. Amer. Janusov, S. 8. 0n the mobility of exchangeable cations in the soil. Soil Sci. 43:285-303. 1937. Jenny, H. and Ayers, A. D. The influence of the degree of saturation of soil colloids on the nutrient intake by roots. Soil Sci. 48:443-459. 1939. Jenny, H. and Overstreet, R. Cation interchange between plant roots and soil colloids. Soil Sci. 47:257-272. 1939. 41 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 42 Joffe, J. S. and Kolodny, L. The distribution and fixa- tion of potassium in the profile of Brown Podzolic soils and sandy Podzols. Soil Sci. Soc. Amer. Proc. 2:239-241. 1938. Joffee, J. S. and Levine, A. K. Fixation of potassium in relation to exchange capacity of soils: III. Factors contributing to the fixation process. Soil Sci. 63:241-247. 1947. Kelley, W. P. Cation exchange in soils. Reinhold Pub- lishing Corporation, New York, 1948. Kunze, G. W. and Jeffries, C. 0. X-ray characteristics of clay minerals as related to potassium fixation. Soil Sci. Soc. Amer. Proc. 17:242-244. 1953. Luebs, R. E., Standord, G., and Scott, A. D. Relation of available potassium to soil moisture. Soil Sci. Soc. Amer. Proc. 20:45-50. 1956. Mortland, M. M., Lawton, K., and Uehara, G. Fixation and release of potassium by some clay minemhs. Soil Sci. Soc. Amer. Proc. 21:381-384. 1957. Raney, W. A. and Hoover, C. D. The release of artifi- cially fixed potassium from a kaolinitlc and a montmorillonitic soil. Soil Sci. Soc. Amer. Proc. 11:231-237. 1946. Reitemeier, R. F. Effect of moisture content on the dissolved and exchangeable ions of soils of arid regions. Soil Sci. 61:195-214. 1946. . The chemistry of soil potassium. Advances in Agronomy. Academic Press Inc., New York. 3:113- 164. 1951. Seatz, L. F. and Winter, E. Potassium release from soils as affected by exchange capacity and complementary ion. Soil Sci. Soc. Amer. Proc. 8:150-153. 1944. Stanford, G. Fixation of potassium in soils under moist conditions and on drying in relation to type of clay mineral. Soil Sci. Soc. Amer. Proc.12:167-171. 1947. Wiklander, L. The chemistry of soil potassium. Advances in Agromony. Academic Press Inc., New York. 3:113- 164. 1951. 43 25. Wiklander, L. and Gieseking, J. E. The chemistry of soil potassium. Advances in Agronomy. Academic Press Inc., New York. 3:113-164. 1951. 26. Woodruff, C. M. The energies of replacement of calcium by potasSium in soils. Soil Sci. Soc. Amer. Proc. 19:167-171. 1955. 27. York, E. T. Calcium-potassium interrelations in soils and their influence upon the yield and cation content of certain crops. Ph.D. Thesis. Dissertation Abstract. 1949. 44 APPENDIX 45 TABLE 4 QUANTITATIVE ESTIMATION OF THE CLAY MINERALS* Sample ‘ ' ' Number I K C M V Q 205 x xx xx 0 xxxx x 395 xxx xx xx x x x 349 x xx xx xx xx x 142 x xx xx 0 xxxx x 337 xx xx xx xx xx x 55 xx xx x xx xx x 30 xxx xx xx x x x 166 xx xx xxx x x x 157 xxx xx xx 0 xx x 146 xxx xx xx x xx x 158 xxx xx x 0 xx x 42 xxx xx xx 0 xx x 24 xx xx xxx xx 0 x 141 x xx xx 0 xxx x 180 xxx xx xx 0 x x 108 xxx xx xx x x x 159 xxx xx xx x x x 27 xx xx xxx x x x 63 xx xx xx xx xx x 107 xxxx xx x x x x 25 xx xx x xx xx x 46 TABLE 4 (CONTINUED) SamETe Number I K C M V Q 71 xx xx x xx x x 21 xxxx xx x 0 xx x 52 xxx xx x xx x x 11 xx xx xx x xx x 18 xx xx xx 0 xxx x 126 xxx xx xx x x x 185 xxxx xx x x x x 192 xxxx xx x x x x 8 xxx xx x 0 xxx x Legend: x:0-10 percent. XX=10-3O " xxx=30-50 " xxxx=50-7O " I=Illlte K:Kaolinite C=Chlorite M:Montmorillonite V=Vermiculite Q=Quartz *The quantitative estimation of the clay minerals was determined byiskg the specific surface values of the pure clay minarais;and the total potassium in the 142 u clay and by solving simultaneous equations. 47 TABLE 5 AI, PLANT WEIGHT, TOTAL POTASSIUM POTASSIUM IN PLANTS, AND PLANT K/ Ca+Mg Number (mgms) (fl?) (%) Kim 30 955 197 1.92 1.52 5.37 180 961 27 2.32 1.28 1.73 158 805 230 2139 1.97 7.44 185 840 6 3.23 1.24 1.45 108 1,045 23 2.12 0.75 1.22 192 783 8 2.68 0.75 2.21 337 826 75 1.23 0.72 1.53 157 707 23 2.02 1.60 5.65 21 726 48 2.82 0.58 1.93 146 729 45 1.78 0.62 0.89 126 699 37 1.95 0.53 0.79 42 686 57 1.85 0.95 1.22 24 734 63 0.97 0.51 0.74 142 671 28 0.78 0.50 1.07 107 749 100 2.72 0.60 1.46 18 699 30 1.20 0.42 0.50 25 718 39 1.47 0.35 0.76 166 726 42 1.18 0.42 0.79 27 677 35 1.43 0.43 1.04 141 717 12 0.90 0.48 2.15 11 707 0 1.41 0.29 0.58 48 TABLE 5 (CONTINUED) Sample SETSEt AI (Z) 3228; 81;; PTaAES Plant Number (mng) 1%0. (%i KZJEETME 159 683 67 2.08 0.79 1.72 8 467 27 1.71 0.30 0.66 63 597 14 1.19 0.38 1.10 52 697 32 1.96 0.16 0.34 55 701 159 1.18 0.49 1.27 71 575 118 1.32 0.15 0.34 395 506 64 1.94 0.27 1.35 205 502 0 1.09 0.25 1.25 349 601 0 0.46 0.28 1.06 49 X-RAY DIFFRACTION PATTERNS W Sample Number Soil Type Horizon Page 30 Brookston loam A1-2 51 180 Ontonagon silty clay Ap 52 158 Paulding clay C 53 185 Selkirk clay c 54 108 Conover sandy loam C 55 192 Selkirk clay loam C 56 337 Iron River silt AD 57 157 Paulding clay C 58 21 Miami sandy loam B 59 146 Coldwater sandy clay loam AD 60 126 Miami sandy loam C 61 42 Paulding clay C 62 24 Brookston sandy loam A1 63 142 Mancelona sand B1 64 107 Conover loam 82 65 18 Miami sandy loam A1 66 25 Brookston sandy loam B1 67 166 Coldwater sandy loam B2 68 27 Brookston sandy loam 82 69 141 Mancelona sand AD 70 ii Spinks sandy loam A1 71 159 Brookston clay loam Ap 72 8 Granby sand 829 73 5O X-RAY DIFFRACTION PATTERNS (CONTINUED) Samp e Number Soil Type Horizon Page 63 Spinks sand A 74 52 Fox sand C1 75 55 Warsaw loam B1 76 71 Warsaw sand 81 77 395 Munising loam C 78 205 Saugatuck sand A2 79 349 Mariensco sandy loam 8p 80 l = Calcium saturated, glycerol solvated. 2 = Potassium saturated, heated to 110 degrees centigrade. 3 = Potassium saturated, heated to 550 degrees centigrade. S.F. = Scale factor. A = Angstroms a , n,” 77,.7 “2‘59; ”1mg ‘95.: - 363A 5| 30 BROOKSTON LOAM SFB 7A IOA |4A |77A 52 353A 7A IOA |4A |77A |80 ONTONAGON SILTY CLAY 8138 U L; a A I A 1 A l n a 1 A A l A A l 30° ’ . . ¢ . - V w - -2..- _ -uv~—_——-¢~‘-M.W' ' -' ' " 7-~ ~, ’-' ‘ ' "r 9. ~" *‘ ‘ =" -' ' -"' 3' — ‘I- "' _:mw:<3fl:bea§<¥m -. ' 7' 75-877“ A ii‘jifflAué— "1 ’»-. ’ 7A IOA 14A 177A 53 333A 1 l58 PAULWNG CLAY SFB 3.33A , , , rrmnwcmgfimr-Blgb 5N3“‘.5:;;?5;"¢ fifth"; g."‘\‘ 5 .. a ‘ 7A I85 SELKIRK CLAY SF. 4 IOA I4A l7.7A 30° 20 333A 55 I08 CONOVER SANDY 8134 3 2 LOAM 7A IOA l4A 30° 29 2° . _~~..mu_—_.- __v \ ....,!...;¢:,- _ , -- , p. . ,_ , , . 3.33A 56 7A |0A 14A 17.7A l92 SELKIRK CLAY LOAM SF. 4 36° ‘26 333A 57 IRON 337 RIVER SF. 4 7A IOA |4A l7.7A SILT 30° 3.33A 58 157 PAULDING CLAY SF. 8 7A IOA l4A I7.7A 59 2| MIAMI SANDY LOAM SF. 4 7A IOA l4A I7.7A 6O 3.33A 7A IDA l4A I7.7A I46 COLDWATER SANDY CLAY LOAM S.F.4 333A 61 I26 MIAMI SANDY LOAM SF. 4 7A IDA l4A I7.7A 30° 2° 7A IDA l4A l7.7A SSSA I .2 PAULDING CLAY S. F.8 a A l ‘ ‘ ‘ l l l A l 1 l 1 A l a I ' ‘ ‘ ‘ 30° 2° 7A IDA l4A l7.7A SSSA I .2 PAULDING CLAY S. F.8 A A l ‘ ‘ ‘ l l l A l A l 1 A l A I ' ‘ ‘ ‘ 30° 2° 3.33A 7A IOA 14A |7.7A I- 63 24 BRDDKSTDN SANDY LOAM S.F.4 _ ______ __..___..-. ..,_.,xr,. . ma..-,,_fl,.“‘ .mwmh- 1w.~.=,;=r..:>~.-.‘u. .=..‘. .;. , m:..-.;;mm~wwrmm',x.~na.:-_<"dfxi__ag_ Q'tgwj_:§f;5l.1;“ .i-..: :2, i=5; .2 3 f; . 3.3fiSA 64 I42 7A IOA ‘ 14A I77A MANCELONA SAND I s+i4 30° 3° 26 65 7A l4A I7.7A 7 ' I 3.33m I07 CONOVER LOAM ‘ SF. 4 .1 I : 3 2 I ‘ ‘ 30° ‘ 1 n n 1 . l 1 n I . I . ‘ ‘ 1 1 L A J . ‘ . I _‘ 66 3.33A 7A IOA l4A I7.7A I8 MIAMI SANDY LOAM {I . h S.F.4 = 28 67 7A IDA I4A I77A 383A 25 BROOKSTON SANDY LOAM S+24 A 3 I 2 I 36° ’ ' ‘ ‘ ‘ ' 1 . - - - . . . . . . .- . . . . . . . . . é: 29 68 7A IDA I4A I7.7A 3.33A I66 CDLDWATER SANDY LOAM SF. 8 . ' A I A . A A l A A A A A . A . j ‘ l J ‘ A A A A A J ‘ A V, L _A 30° 2° -m_mmmmt ~ - £3.33; a: - ém;_:_’xmmm;;r Ami:.‘ ;_xg.‘7_3f‘3.3 zit» L ‘:.':_,. _' 4' 7. _ _ ""' 69 7A IDA I4A LITA 3&33A 2‘7 BRDDKSTDN SANDY LOAM S.F.4 P A A l A A A A A A A n . l ‘ A A ‘ . ‘ l l A A A 30° 2° 2533A 70 I4! MANCELDNA SFZ4 SAND 7A IDA I4A |77A 30° 2533A 70 I4! MANCELDNA SFZ4 SAND 7A IDA I4A |77A 30° 3.33A 71 7A II SPINKS SANDY LDAM S.F.4 IDA I4A I77A 30° 72 7A IDA I4A I77A 333A I59 BRDDKSTDN CLAY LDAM 8138 Lg A A A A A A A l A A A l A ‘ l 7 ° 3 0° ' 20 73 333A 7A IDA I4A I77A 8 GANBY SAND 61:4 "'“A Iv‘. 3.33A 74 7A IDA I4A I7.7A 63 SPINKS SAND SF. 4 _. ~o—mm-w —-w~,—— , qgfi-A—Ww—uurm.-m.- —_, 333A -..rW,W~-~~0—-—o H¢-Vx“a . m: 4-- A»- ~~-- -L.-.—'-_.ru.._‘ - . ‘-. ‘ "~ 75 52 FDX SAND SF4 7A IDA I4A I77A 7A IDA I4A I77A 3.33A 55 WARSAW LDAM SF. 8 o A A 1 L A A A A A A A A l A A A A A I A A I - ‘ ‘ A V 30° 2 77 7A IDA I4A I7.7A 3.33A WARSAW SAND SF. 8 ' 7| A . "—~ 1 A A A A A | A . I l I A A . . A A A L ‘ J V 26 3.33A 395 MUNISING LOAM S.F.4 7A IOA I4A l7. 7A I. 333A l ' H 79 1' i 3 205 SAUGATUCK SAND s S. F. 4 7A IOA I4A {17A 3 2 ! F | 30° ~ . ‘ 2° 29 . 80 3.33A { 349 MARIENSCO SANDY LOAM I SF. 4 7A IOA I4A I7.7A & F.--—_—‘-—“- ROOFA USE ONLY ‘-__. .. MICHIGAN STATE UNIVERSITY LIBRARIES 3 1193 O304J1514