THE EFFECT OF VARIOUS ORGANIC AMENDMENTS ON THE PHYSICAL AND CHEMICAL PROPERTIES OF SEVERAL SOILS AND CLAY MINERALS By John Arthur Archibald AN ABSTRACT Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Soil Science 195^ Approved THE EFFECT OF VARIOUS ORGANIC AMENDMENTS ON THE PHYSICAL AND CHEMICAL PROPERTIES OF SEVERAL SOILS AND CLAY MINERALS ABSTRACT The effect of a number of organic amendments on the physical and chemical properties of a typical Ontario grape soil was measured* Although several of the materials markedly improved aggregation, por­ osity, and other physical properties, there was no significant differ­ ence in grape yields between treated and untreated plots* Following the field experiment, a laboratory study was made of the effect of soil conditioners on the ion-exchange properties of four Ontario soils, Wyoming bentonite, and kaolinite* Preliminary ex­ periments indicated a marked effect of small amounts of conditioner on cation-exchange capacities of soils and clays* A detailed study was made of the effect of various concentrations of the acid form of VAMA, a vinyl acetate—maleic acid copolymer, on the cation-exchange properties of a hydrogen-saturated bentonite* It was found that at very low concentrations of VAMA, the cation-exchange capacity of the clay-conditioner mixture dropped rapidly. Slight in­ creases in conditioner concentration resulted in a large increase in exchange capacity* As conditioner concentration was further increased, the cation-exchange capacity again decreased, and remained below theo­ retical value for the clay-conditioner mixture at all higher concen­ trations used* This evidence shows conclusively that there is an ionic exchange reaction between a VAMA-type conditioner, and a montmorillonite-type clay. THE EFFECT 07 VARIOUS ORGANIC AMENDMENTS OH THE PHYSICAL AND CHEMICAL PEOPSETIES 07 SEVERAL SOILS AND CLAY MINERALS By John Arthur Archibald A THESIS Submitted to the School of Graduate Studies of Michigan State College of. Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR 07 PHILOSOPHY Department of Soil Science Year 195^ ProQuest Number: 10008250 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest, ProQuest 10008250 Published by ProQuest LLC (2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 1 0 6 - 1346 ACKNOWLEDGEMENT The author wishes to express his appreciation to Dr. A. E. Erics­ son for directing his graduate work* and to Dr. M. M. Mortland for helpful suggestions on the laboratory experiments. Thanks are due Mr. G. W. Hostitter and Mr. A. E. Neff of T. G. Bright and Co. Ltd., who provided land for the field experiment, said helped in taking measurements during the course of the experiment. Dr. E. 7. Palmer, Director, Horticultural Experiment Station, Ontario Department of Agriculture, made a leave possible and Mr. R. G. Mercier, and Miss E. I. Ferguson, of the above Station helped in carrying out the research program. The scholarship granted by the Agricultural Institute of Canada, and the Hinman Graduate Fellowship, awarded by the Graduate Council of Michigan State College provided much appreciated financial help. TABLE OF CONTESTS I. INTRODUCTION........................... . ............ 1 II. REVIEW OF LITERATURE.................................. 3 A. B. The Effect of Organic Soil Amendments on G-rape Production 3 Development of Soil Conditioners............. 5 III. EXPERIMENTAL............................................ 10 A. Field Experiment . 10 Experimental methods Results .......... 10 . . . . . . . . . . . . . . . . . . . . . . . . Discussion 13 • 29 Summary B. J2 Laboratory Experiment 1* ........... The effect of a number of different conditioner materials on aggregation and ion-exchange properties of fourOntario soils .............. 33 Results and discussion • • • • • • 2, 33 .............. . The effect of conditioner concentration on the ion-exchange properties of Wyoming bentonite, kaolinite, and a Jeddo clay loam soil . . • • « . » - Results and discussion 3* 3? ^7 A7 Cation^exchange properties of Wyoming bentonite and kaolinite treated.with a wide range of conditioner concentrations • • • • • • • • . • • • • 53- Results and discussion ....... . .. . .. . .. . 53 • • • • • • . » • • • • • • • • 63 Summary and Conclusions IV, LITERATURE CITED........................................ 71 LIST OP FIG-UEES Figure 1* Cumulative Percent Porosity of a Jeddo clay loam soil held at various moisture tensions, after treatment with several organic amendments................ ....... 16 Figure 2. Cumulative percent aggregation, of a Jeddo clay loam soil treated with organic amendments, six weeks after treatment ................ 13 Figure 3* Cumulative percent aggregation of a Jeddo clay loam soil treated with organic amendments, eleven months after treatment • 20 Cumulative percent aggregation of a Jeddo clay loam soil treated with organic amendments, thirteen months after treatment 22 Cumulative percent aggregation of a Brookston clay soil treated with a number of organic amendments •• • • • 46 Figure 6* Cumulative percent aggregation of a Jeddo clay loam soil treated with a number of organic amendments .• • • • 47 Figure 4. Figure 5* Figure 7* Cumulative percent aggregation of a Burford loam soil treated with a number of organic amendments •♦ • • » 48 Figure 8. Cumulative percent aggregation of a Guelph loam soil treated with a number of organic amendments •• . • • 49 Figure 9» Effect of low concentration of VAMA on the cationexchange capacity of H-bentonite for sodium ion •• * • . 54 Figure 10. Effect of high concentrations of VAMA on the cationexchange capacity of H-bentonite for sodium ion • • • • • 55 Figure 11. Typical titrationcurves of H-bentonite treated with VAMA and titrated with HaOH ........... 56 Figure 12. Typical titrationcurve of VAMA titrated with HaOH 0.01 gm. VAMA ♦ • * . . . ........... • ................ 57 Figure 13« Effect of low concentrations of VAMA on the cationexchange capacity of H-bentonite for calcium ion • . • • • 58 Figure 14. Effect of high concentrations of VAMA on the cationexchange capacity of H-bentonite for calcium ion • . . • . 59 Figure 15* Figure 16. Typical pH and conductance titration curves for H-bentonite treated with twelve percent VAMA and titrated with CafoH^* • 6l Effect of various concentrations of VAMA. on the cation-exchange capacity of E-kaolinite for sodium ion • • • • • • • » » » • » » * « . • • * • • • • 62 Figure 17* Titration curve of H-bentonite titrated with VAMA . . . • 63 Figure 18. H-bentonite titrated with IBMA titration curve • • • • • 64 . • 65 Figure 19* Titration curve of Na-bentonite titrated with VAMA • Figure 20« Titration curve of Ca—bentonite titrated with VAMA ... 66 LIST OF TABLES Talkie I ' \Table tII Table III The Effect of Organic amendments on cumulative percent porosity of a jeddo clay loam soil held at various moisture tensions • • • • • • * • • • • • • 17 Percent aggregation of a Jeddo clay loam soil treated with various organic amendments six weeks after treatment • • • * • * . * 19 . - Percent aggregation of a Jeddo clay loam soil treated with various organic amendmentseleven ............ months after treatment 21 Percent aggregation of a Jeddo clay loam soil treated with various organic amendments thirteen ................ months after treatment 23 Mean volume weights and permeabilities of undis­ turbed soil cores from a Jeddo clay loam soil treated with a number of organic amendments • • • • • • 24 CatioDr-exchange capacities and exchangeable sodium, calcium and potassium content of a Jeddo clay loam soil treated with various organic amendments • • . • • 25 Organic matter content in percent of a Jeddo clay loam soil treated with various organic amendments at two different sampling dates • • • • • • * . . • • • 26 Table VIII Yields of Agawam grapes for 1952 and 1953 in pounds of fruit per vine grown on a Jeddo clayloam soil treated with various organic amendments • • • • • • • • 27 Table IV Table V Table VI Table VII Table IX Table X Table XI Yield of wheat cover-crop in pounds per acre grown on a Jeddo clay loam soil treated with various organic amendments « 28 Mechanical composition of the four soils used as determined by the Pipette method of analysis • • • • * 40 The effect of eight conditioner materials on the cation-exchange capacity, expressed in milliequivalents per 100 grams soil, of four soils used • • • . . 4-1 Table XII Table XIII Percent water stable aggregates greater than 0.1 mm. in four soils treated with eight conditioner materials . • • • . • • • • • • • • • • » . ^2 The effect of four concentrations of three different conditioners on the cation-^exchange capacities of Wyoming Bentonite, Kaolinite, and Jeddo clay loam, as determined by the ammonium acetate method 50 I. INTRODUCTION The recent introduction of soil-conditioning materials has re­ sulted in an upsurge of interest in the value of organic soil amend­ ments* Perhaps the greatest value of these new conditioners is that they have created more interest in the whole field of clay—organic complexes. Even if they do not become widely used, the knowledge obtained from their study will add greatly to the field of Soil Science. In the Niagara Peninsula of Ontario, an area favored by the moderating influences of Lake Ontario and the Niagara Escarpment, there are grown about 20,000 acres of grapes* Because of a relatively low acre-return of this crop compared to peaches and other tree fruits, grapes are invariably put on soil unsuited to other fruits. The ave­ rage grape soil is fine—textured, compact, and low in organic matter. On such soils, naturally fertile but unproductive, additions of fer­ tilizer materials have not increased yields. Organic matter additions have increased yields consistently. With this fact in mind, it was felt desirable to compare the effects of soil conditioners presently available with conventional or­ ganic supplements, to evaluate their effects on soil properties. The first part of this thesis then deals with the effect of these organic amendments on a typical Ontario grape soil. In the short time that conditioners have been available for ex­ perimental work, much has been learned of their effect on physical properties of soils* Little is yet known of the nature of the clay- organic union which is assumed to form the basis of their action* A series of laboratory experiments were made in an attempt to elucidate the nature of the clay-organic linkage, or at least to accumulate information on the effect of various conditioner materials on the properties of several representative soils and clay minerals* II. REVIEW OF LITERATURE Part A - The Effect of Organic Soil Amendments on Grape Production There is considerable evidence to indicate the value of organic matter additions, and of high organic content of soil, in grape pro­ duction. This evidence has accumulated from work done under widely varied conditions of climate and soil. Partridge and Veatch (21) working in southwestern Michigan on Plainfield, Fox, and Oshtemo soils, pointed out that variations in the thickness of the humus layer of the surface soil had more influ­ ence on vine growth and production than did any other soil factor. Fruit production on humus layers three to six inches in depth was double that where the humus layer was less than three inches. Gourley (9) iu Ohio, reported yield increases from applications of manure, Cooper and Vaile (4), in Arkansas, also found that moder­ ate manure applications increased the yield of Concord grapes. Faurot (6), working in Missouri, has shown that manure appears to be of greatest value for use on older, established vineyards. He further found that the use of commercial fertilizer, of various analyses, and at varied rates, did not produce yield increases sufficient to pay for the cost of the materials used. Upshall et al (31)* carried out a long-term experiment with the Concord grape in the Niagara Peninsula of Ontario, on a Vineland clay-loam soil. soil. This soil is poorly drained, with a heavy clay sub­ The experiment was begun in 1929 and concluded in 1948. Var­ ious rates of application of nitrogen, phosphorus, and potassium fertilizers were used alone, and in combination. In addition hay and straw treatments were included, alone, and in combination with the above fertilizer materials. The hay and straw treatments were the only ones that produced continuous and statistically significant yield increases* manure crops tended to produce higher yields. G-reen- A complete fertilizer did increase growth and total dry matter content of green-manure crops and in this way fertilizers may have indirectly influenced crop returns. The above evidence, particularly that from Ontario, indicated that organic soil amendments are of great value in grape production. There is little evidence presented, however, on the actual effects of such amendments on soil properties. It was confined in most cases to the effect of treatment on crop yield. Part B - Development of Soil Conditioners The nature of the clay-organic complexes involved in soil aggre­ gation and stabilization is a problem which has received considerable attention in the past several years. Following the introduction of the new *soil—conditioners,w interest was intensified# Gieseking (7) in 1939 was able to spread the c-axis spacing of montmorillonite by the addition of organic bases# Ensminger and Gieseking (5)* in 19^2, showed that adsorption of proteins on the base—exchange complex interferes with normal enzyma­ tic hydrolysis# This interference was dependent on the base-exchange capacity of the clay, and was greatest at lower pH values. Norman and Bartholomew (19)» in 19^3* found evidence of combina­ tion of uronides with clay particles# Uronides are constituents of hemicelluloses, pectins, mucilages and gums# The higher the number of uronic groups, the greater the resistance of these compounds to decomposition# These materials have been shown to be of value in soil aggregation# Martin (15)* was able to show in 19^6, that bacterial poly­ saccharides were definitely responsible for increased aggregation and stability# Quastel and Webley (26), found that methyl cellulose and car— boxymethyl cellulose had good aggregating effects, but decomposed readily. Van Bavel (32), in 1950# found that the use of dimethyl dichloro eilane stabilized structure and produced a waterproofing effect# This increased stability may have "been due to the slower rate of wetting when placed in the wet-seiving apparatus* A serious disadvantage of this gaseous material lies in its toxicity to animal life. Hedrick and Mowry (10) point out that polyuronic acid salts, and related polysaccharides have not proven successful because: (a) the large quantities needed release toxic quantities of cations (b) the large amounts of rapidly decomposable organic matter upset the micro­ biological balance of the soil (c) the rapid microbiological decom­ position of added polysaccharide derivatives makes the use of such materials uneconomical. These authors found that the sodium salt of a hydrolyzed polyacrilonitrile (released as Formulation 9 by the Monsanto Co.) of general formula H - C H -- H C = 0 C- 0 - Ha X and the calcium salt of a modified vinyl acetate-maleic acid compound (Formulation 6) - CH - CHg - CH - CH 0 CODE COOR C m 0 CB3 vrere effective in stabilizing structure. X Further, these water-soluble polymeric electrolytes of high molecular weight were effective in extremely low concentrations. These authors also showed by the Warburg technique that these two materials were non-toxic to yeasts and other soil organisms* Also, trace—element availability was not affected, and the materials were not toxic to higher animals. The leaching losses of the polyelectrolytes from a treated soil were negligible. Although they found that abietic acid, silicates, and volatile silicones also stabili­ zed structure, the water-proofing effect lowered the water holding capacity. Ruehrwein and Ward (29) used sodium polymethacrylate, a poly—anion, and poly B-dimethylaminoethylmethacrylate hydroacetate, a polycation, to study the mechanism of clay aggregation by polyelectrolytes. Using Wy­ oming bentonite, they found by Xr-ray diffraction measurements that the c-axis spacing of the montmorillonite was increased by the polycation but npt by the polyanion, thus indicating that polycations but not poly­ anions are adsorbed in the inteiplanar spacing of montmorillonite. also found the polycation to be an effective flocculating agent. They The polyanion did not act as a flocculating agent, but was effective in sta­ bilizing flocculated clay. They state that it is possible for sodium polymethacrylate to bridge between two clay particles, since the length of the molecules is comparable to that of the clay particles. For a given heat of adeorptiono the adsorption of the polyanion on clay is more likely than that of simple ions, due to the smaller entropy of adsorption of the polyelectrolyte. Martin et al (17) used HPAH (Krilium 9) and VAMA (Krilium 6) on Miami, Crosby, Brookston and Paulding soils. They found a marked stabilization of aggregates, with the major portion of the particles stabilized in the two to five mm*, and greater than five mm*, size ranges. Of a variety of crops grown, corn, oats, and carrots were most responsive. These authors also showed that soil crumbs treated with either of these materials remained stable for 32 months at 76 JP« Allison (l) showed the value of the two Erilium conditioners on saline soils. They reduced crusting and resulted in a much higher rate of seedling emergence* Weeks and Coulter (33) studied the effect of HPAN on erosion control. They found that the material was of value in temporarily controlling erosion until vegetation became established. This material, however, was not superior to straw mulch for reducing runoff and erosion. W* P. Martin (l6) in a recent article summarizes the early re­ sults with VAMA.and HPAH on Ohio soils. He points out the value of these materials for increasing water infiltration rate andearly spring drainage. may explain the fact that he found This dates for a variety of crops on treated soils. He earliermaturity also found that conditioner applications may result in greater crop response to fer­ tilizer materials. Sherwood and Hngibous (30) in a similar paper state that ionexchange capacities may be affected by treatment with conditioners. They indicated that an application of 0.15 percent conditioner de­ creased cation-exchange capacity in treated soils* To summarize, the interaction between clay, and organic cations and anions, has received considerable attention in recent years. Recent interest has centered mainly around two materials, the sodium salt of a hydrolyzed polyacrilonitrile and the calcium salt of a modified vinyl acetate-maleic acid compound. These materials are effective at low concentrations in stabilizing soil structure, and are less readily decomposed than the naturally-occurring polyuronides which have been shown to be of value in improving soil structure and stability. An ideal synthetic soil conditioner then, should be effective for long periods in stabilizing soil structure without reducing water holding capacity. It should have a low rate of destruction, and should not adversely affect biological activity, either by toxic effects on plants or animals, or by disturbing microbial activity. Also, it should not remove trace elements necessary for plant nutri­ tion. Once a material meets these conditions, it must then be deter­ mined whether it can be produced in large quantities economically enough to make its widespread use as a soil conditioner practicable. III. Part A. EXPERIMENTAL Field Experiment Experimental Methods The field experiment was carried on in the grapery of T. G. Bright and Co* Ltd., in Niagara Township, Lincoln County, Ontario near the ham^ let of Virgil. The experimental plots are part of a 1000 acre tract of land owned by the above Company and used solely for grape production. The soil is typical of Niagara Peninsula grape soils, and has been ten­ tatively classified as a Jeddo clay loam, by the Ontario Soil Survey staff. Since the Soil Survey Report for Lincoln County has not yet been written, the following description was taken from notes of the Sur­ vey staff. Description of soil. The Jeddo soils are developed on heavy sub­ aqueous till from calcareous materials. The weathered profile is more acid than the Brookston and lacks distinct color and textural horizons. The Jeddo is the poorly drained member of the Haldimand catena, the Caistor being the imperfectly drained member. It exhibits character­ istics in accord with those of the Gray Hydromorphic Soils. Profile. A1 — Four inches; dark gray clay to silty clay; sticky; some grit; pH 5.8. A2 - Six inches; very dark gray clay with yellowish brown mottlings; some grit; pH 5*8. Cr — Twenty inches; gray clay with light yellowish brown mottlings; structure large to massive; sticky; some grit; pH 6.2* C — Fine gray till with some light yellowish brown mottlings; some grit, stones, and dark colored shale fragments; massive; sticky; pH The topography is level to gently undulating, with small depress­ ions! areas. Both external and internal drainage are poor. The native vegetation was elm, soft maple, hickory, swamp and bur oak. The major difference between the Jeddo and Brookston series is the lower pH and the larger proportion of shale found in the Jeddo. The Brookston has a higher organic matter content, a darker surface, and the profile contains a slightly greater concentration of rusty-colored mottles. Plot design. A randomized block experimental design was used, with ten treatments, and four replicates. The plot size was eleven by thirty feet, with buffer rows between series. The six grape vines bordering the plots were used for recordpurposes. The grapeswere variety, a red grape widelygrown forwineproduction the Agawam inthat area of Ontario. Treatments. The following treatments were used in the experiment: 1. VAMA (Krilium 6) 2. HPAN (Krilium 9) 3. Sugar A. Lical 5* Sawdust 6. Grape pomace 7. Alfalfa meal 8. Straw 9. Lionex 10# Check The straw, alfalfa meal, sawdust, sugar, and grape pomace were applied at the rate of five tons per acre on a dry matter basis# The two Krilium formulations, the VAMA. and HPAH previously described, were applied at the rate of 1000 lbs# per acre# The Lionex material, a catioifr-exchange resin produced as a by-product of the paper milling industry, and the Lical, a paper mill waste largely composed of lignin and lime, were applied at the rate of one ton per acre# The Lionex material had given evidence of promise as a soil conditioner* All materials were spplied on August 1, 1952, and immediately incorporated in the soil to a depth of six inches with a large self-driven rotary tillage implement# Hitrogen as ammonium nitrate was applied to the sawdust, sugar, straw and grape pomace plots to maintain a C/ft ratio of approximately 20s1# This nitrogen was applied as a split applicap­ tion, half at time of treatment and half the following spring, except in the case of the sugar plots, where the total amount was applied at the time of treatment# A cover crop of wheat was sown August 15, 1952, and was worked down the following May# Soil samples for organic carbon and aggregate analyses were taken in late September, 1952, at the zero to six inch depth* Organic content on these samples was determined by the wet combustion method of Walkley (33)* The wet seiving technique of Yoder (36) was used for the aggregate analyses. Duplicate determinations were made on all samples. Undisturbed, three inch soil cores were taken in April, 1953. cores were taken from each plot. Six These cores were used to determine pore size distribution, permeability, and volume weights (27). In July of 1953, soil samples were taken again for aggregate analyses, and organic carbon determinations. In addition, cation-ex­ change capacity was determined by the ammonium acetate method. Exchange­ able potassium, calcium, and sodium contents were determined on all sam­ ples by the methods outlined by Peech, Alexander, Dean, and Reed (22). Oxygen diffusion readings (13) were taken during the summer of 1953* In September 1953, sailings for aggregate analyses were again made. Individual vine yields were recorded for both 1952 and 1953* Cover-crop yields were taken in May of 1953, just before the green cover was worked into the soil. Results At the time of application of the organic materials mentioned ear­ lier, it was noted that the HPAU material was very hygroscopic, and stuck readily to anything with which it came in contact. This is a serious disadvantage of this material, in that if the soil is not rather dry at the time of incorporation, it will form large rubbery masses. Several weeks after application, following a rather heavy rain, a large amount of brownish viscous exudate appeared on the soil surface of the BPAN-treated plots. This material apparently had picked up large amounts of colloidal organic matter from the soil. mained on the surface for at least a month. This exudate re­ The cumulative percent porosities are shown in Table I for all treatments. Since the values for ell treatments except the VAMA, EPAH, Lical and Check were very close together, only these four are shown in Figure 1. The difference due to the VAMA treatment is great, and is noticeable even in the very large pore sizes* The HPAK-treated soil showed porosities greater than were found in any other soil except that treated with VAMA, although in the case of the smaller pores, the Lical treatment was more effective* All other treatments produced results which fell between those obtained for the check and the Lical material, and to avoid confusion were not included in Figure 1* The distribution of stable aggregates in the surfaces of the plots, as determined by wet-seiving are shown in Tables XI, III, and IV for the sampling dates September 1952, July 1953, and September 1953* Figures 2, 3, uud k show the cumulative percent aggregation for the VAMA, HPAU and check plots for these dates* There again, all treatments were not shown on the graph to avoid confusion* It can be seen that in September 1952, about eight weeks after treatment, there was a large response to the Krilium formulations* The response was not nearly as evident in July of 1953, but was again noted in September of that year* The water permeabilities and volume weights are shown in Table V. It will be noted that all treatments except the Lical and grape pomace greatly increased the permeabilities* The VAMA treatment was far sup­ erior to all others* Only the two Krilium materials produced significantly lower soil volume weights, although all treatments resulted in somewhat lower values than were found for the untreated soil* In Table VI are shown the exchange capacities and amounts of some exchangeable cations* It will be noted that the HPAH and Lical treat­ ments were the only ones which caused significant increases in cation exchange capacity* These materials were also the only ones which gave significant increases in exchangeable calcium* The HPAH material approximately doubled the exchangeable sodium content of the soil* Ho treatment significantly changed the exchangeable potassium level* Organic carbon content, Table VII, was not changed significantly by treatments, due to replicate variability. There was a trend towards higher organic carbon contents in the soils treated with large amounts of organic material* There was also a consistent seasonal variation between September of 1952 and July 1953* Grape yields for the two years 1952 and 1953 VIII. shown in Table It will be noted that all yields were much higher in 1953 than in 1952. This was general in this grape-growing area, and was not due to treatment* The cover-crop yields are shown in Table IX* Here, the plots which received nitrogen, or an organic material high in nitrogen such as alfalfa produced the highest yields. There were no significant differences between the yields from the Krilium plots and those from check plots* 16 10 Pore space - percent 12 Check 0.01 0.02 0.03 0 .0* * 0.06 0.33 0.50 1.00 Tension-atmo sphe res Figure 1* Cumulative Percent Porosity of a Jeddo clay loam soil held at various moisture tensions, after treatment with several organic amendments. . THE EFFECT OF OB&ANIC AMENDMENTS ON CUMULATIVE PEBCENT FOBOSITT OF A JEDDO CLAY LOAM SOIL HELD AT VABIOUS MOISTUBE TENSIONS 17 o o Ov • o- CM • DiH o MV • o CM • o- v/•V rv • 4H o H Ov ■ vo rv Ov 4 vv 00 00 CM so o• o WV VO rv OV 4 o* oo OV vf\ rv CM OV ov IN* CM IN- «V C*V 4 rv rv rv rv o o• rv UV 4 • • rv rv «v « rv CM• rv 4■ -4* • ov ov o cm CM CM rv cm OV CM «H vo CM CM rv • o 00 o tv • r-t r-4 H • O H Cv• CM iH 4. o O• O ft CO OV CO rv CM C 13 rH •03 m p« 0) §* U Ci5 I 4> CO Aggregation - percent 100 -9- Check 20 4-HPAN 10 0.1 0.25 0.5 2.0 5.0 Aggregate size - ram Figure 3. Cumulative percent aggregation of a Jeddo clay loam soil treated with organic amendments, eleven months after treatment 21. vo • CM rv V O• VO • oo • ov CM vO • Ov CM CM • ^4• IN- 58 VO CM CM 00 CM • O • O rv -3" rv vo • or\ • oo • vo• rv CM rv rH VO CM Ov rv oo• 00 rv •a 4O* EH o A vO C- CM 00 ^5** • I PERCENT AGGREGATION op a JEDDO CLAY LOAM SOIL TREATED WITH VARIOUS ORGANIC AMENDMENTS ELEVEN MONTES AFTER TREATMENT *>- H A CM vr\ -3• o rH oo o CM CO • OV rH CM m rv rH CM oo VO • #H rH *T\ * rH »H $ rH rH CM • C- vO $ VO 00 CM -=J* vo -3* O * VT\ H CM • VO rH VO • O VO • VO rH O • O rH O • Ov rH VO 00 VO CO Ov 00 VO v r\ 00 VO vo vO 'O CM • rv CM • uv rH rH rH VO • CM vO • -3- vO • O rH CM O O 00 o rH © N •H ia © CM * o vO VO o VO • CM VO • rH CM • CM rH 00 • O • rv -3- CM • vO «0) © vr\ c4 A. rH 00 O CM rH «H rH rH CM • CM vO • O -3 * -H- vo • Ov VO • ^T VO • Ov •d• rH o rH rH • CM rH rH o rH H rH O * O rH ■©a ■s I "3 © Eh El 3 *3 SP •H 01 o rH 4> 03 x£t I © CO o - CA VO OV VO CM CV • Cv- $ g 00 CM 00 -3' ^ VO VO va 00 (A VO 00 O • c- CM co * c- vo CM va va • o ON • ON CM 00 • rH 00 * CA CM VO -3r H -3" * CM «>- Ov « CM -3 - • va CM • 00 vo 00 CM 00 C- • • O • VA VA CM • CM rt 00 * OO © M ■tf °jf © * as © 14 VA c4 'A VO 00 OO ON vo o CM 00 • O«~t O * VA r4 00 « CA rH O • VO rH NO o vo CM CM NO VA CM VA CA vo * VA H CM • O CM CM . 3* • CA rH O CM r| rt ON ON CM • VO r-t O • VA rH O • rH rH CO m * CM CM CA A © o ■§ © a «a © Ert § 4® Mo © # o < sd 3 > 5 M) CO 3o © 6 S CO o Pi © & U <*3 •a § © * 3 «H & g 4® CO M § o TABLE 7 MEAN VOLUME WEIGHTS AND PERMEABILITIES OF UNDISTURBED SOIL GORES FROM A JEDDO CLAY LOAM SOIL TREATED WITH A NUMBER OF ORGANIC AMENDMENTS Treatment Volume Weights Permeabilities Check 1.39 0.5 2 VAMA 1.24 5.87 SPAN 1.29 2.91 Sugar 1.35 1.99 Llcal 1.35 1.18 Sawdust 1.37 1.40 Grape Pomace 1.35 0.63 Alfalfa meal 1 .3 6 2 .0 ? Straw 1.34 2 .3 2 Lionex 1.38 2.16 L.S.D. 5 percent 0*08 1 .0 2 Inches/hour 25. I 01 © rt 4* O rt 0 vr> . vo vf\ rt . O CM rt . -rt O u*\ a VO -r t rt su\ s u-\ VO O {N.- VTi vo O a CM VO rt PH o 73 p VO o. o. rt 00 Ov s rv v r\ • CM rH -r t C^ . O rH O O • rH rH v r\ VT\ • O rH t>Cv- O rv P4 a W © 73 «H 3 H sh F +3 50 § o CO TABLE VII ORGANIC MATTER CONTENT IN PERCENT OF A JEDDO CLAY LOAM SOIL TREATED WITH VARIOUS ORGANIC AMENDMENTS AT TWO DIFFERENT SAMPLING DATES September 1952 July 1953 Check 4.14 4.27 VAMA 4.18 4.35 •17 SPAN 4.21 4.4l •20 Sugar 4.36 4 .5 4 •18 Lical 4.20 4.42 .22 Sawdust 4*24 4.4l .17 Grape pomace 4.19 4.29 .10 Alfalfa meal 4.46 4.59 .13 Straw 4.24 4.36 .12 Lionex 4.17 4.24 .07 Treatment Change , TABLE VIII YIELDS OF AGAWAM GRAPES FOR 1952 AND 1953 IN POUNDS OF FRUIT PER VINE GROWN ON A JEDDO CLAY LOAM SOIL TREATED WITH VARIOUS ORGANIC AMENDMENTS Treatment 1952 1953 Mean Check 15.8 25.3 20.5 VAMA 18.3 25.8 21.8 HPAN I6.5 27.8 22.1 Sugar 15.8 24.8 20.3 Lical 17-3 26.3 21.8 Sawdust 18.3 25.8 22.0 Grape pomace 14.5 25.0 19.8 Alfalfa meal 17.5 25.3 21.4 Straw 18.3 28.3 23.3 Lionex 15.3 24.3 19.8 IABLE IX YIELD OS' WHEAT COVBIUCBOP IH POUHDS PEE ACHE CHOWS OH A JEDDO CLAY LOAM SOIL THEATED WITH VARIOUS OROANIC AMEHDMEOTS Treatment Green Weight Dry Weight Cheek 4 ,250 1,360 VAMA 3,940 1,110 SPAN 4',440 1,200 Sugar 12,500 3,071 Lical 4,520 1,320 Sawdust 9,980 2,490 Grape pomace 4,020 1,090 Alfalfa meal 8,080 2,220 Straw 8,9 1 0 2,400 Lionex 3,970 1,1 2 0 1,7 0 0 430 L.S.D. 5 percent Discussion Some of the most striking differences obtained from the treatments used were in the distribution of pore size in the soils treated with VAMA, HPAN, and Lical* The Varna increased the percentage of non-capil­ lary pores from less than three in the check to eight percent in the treated soils* It should be kept in mind that although this material almost trebled the percentage of non-capillary pores, the level was still considerably below the optimum for such crops as sugar beets, according to Baver and Farnsworth (2)* This soil, then, even at best, has a very small percentage of large pores* It should also be noted that the ex­ perimental grapery has received heavier applications of manure over the past years than has the average grapery in the area, thus its initial physical condition was at least average for this soil, and perhaps better than average* The VAMA was superior to the HPAN under all tension con­ ditions used in the experiment* The increased porosity with the Lical may be due to the high lime content, resulting in microbial stimulation* The other physical measurements made did not indicate any superiority of this material* With regard to aggregation, it is interesting to note that the high­ est percentage aggregates greater than 0*1 mm occurred shortly after application, about six weeks after the materials were applied. probably a seasonal effect* This was The greatest response to conditioner treat­ ment was also evident at this early date* During the following July, both the total percentage of large aggregates, and the differences caused by treatments were less. In the September 1953 sanples, the effect of the Krilium treatments again stood out, and the differences were much greater than in July. fiFAN material. Again the VAMA had proved to he superior to the However, as reported by Martin, the greatest difference was in the higher percentage of aggregates in the larger size ranges. The lack of differences resulting from treatments at the time of the July sampling is probably due to the fact that the soil was worked several times prior to ceasing cultivation about August 1. The culti­ vation tended to destroy the aggregates or at least reduce their size. Once the soil was left undisturbed for a month or more, the effect of treatment was again more noticeable, with more large stable aggregates in all soils. It is also interesting to note that the Lionex and grape pomace treated soils contained a smaller percentage of aggregates greater than 0.1 mm. than did any of the soils treated with the other materials or those which were not treated* The Lionex contained a large amount of sulphur, which may have suppressed normal microbial activity. The acid state of the grape pomace may have resulted in the same effect. The permeability measurements showed that the VAMA had been veryeffective. fold. The water permeability rate was increased more than ten­ However, all materials, except the Lionex and grape pomace at least doubled the infiltration rates as compared with the untreated soil. This would be more important if some economical means could be devised for incorporating these organic materials to a greater depth, so the in­ creased permeability would reach the lower horizon. The volume weight results also indicate the superiority of the VAMA material. A smaller decrease in volume weight was caused by the HPAN material. Here again, even the lowest volume weight indicates a very compact soil. The failure of the oxygen diffusion results to show significant differences as a result of treatment is probably due to the fact that the soil had been recently cultivated. It was difficult to get uniform readings in the disturbed soil, and after cultivation had ceased, the soil was too dry for readings to be taken satisfactorily. With regard to cation exchange capacity and the exchangeable cations measured, explanation is difficult. In the case of sodium, the HPAN ma­ terial, a sodium salt, would be expected to add considerable sodium to the soil. treatment. The sodium content was approximately doubled by the SPAN The difficult fact to explain is that the exchangeable cal­ cium and total exchange capacity were also higher where HPAN was applied. The VAMA material, although it was the calcium salt, did not increase the exchangeable calcium or total exchange capacity significantly despite its greater effect in altering the physical properties of the soil. The ex­ planation may be that the VAMA material was combined more completely with the clay than was the HPAN material, thus reducing some of the exchange positions that would exist were the materials not combined. The failure of the quantity of exchangeable calcium to increase may be explained by the fact that the calcium acts as the cation bond between the negativelycharged clay particles and the conditioner anion. In the plots treated with HPAN, since there apparently was less clay-organic interaction, the exchange sites of the two materials were somewhat cumulative. There were no significant differences between exchangeable potassium levels in the variously-treated soils. The treatments did not significantly affect the organic carbon coiw tent of the soils. Some of the organic materials applied in large quait- tities tended to raise the organic level slightly. That the grape yields were not significantly changed by the treatments is not surprising, in view of the fact that the grape is a long-lived plant, and responds slowly to treatment. However, it was shown that the physical properties of the soil were altered, in what is believed to be a desirable direction. If the reported responses of grapes to organic—matter additions were real, a definite yield increase should be eventually expected. With regard to the cover-crop yields, the only significant yield in­ crease was produced on plots where nitrogen had been applied separately, or in the case of the alfalfa meal, where the material itself contained large amounts of nitrogen. Summary This work was undertaken to study the effects of different types of organic soil amendments on a typical fine-textured Niagara Peninsula grape soil. Treatments included two new Krilium soil-conditioners, VAMA and SPAN, and a*number of more commonly-used soil amendments. The two Erilium materials were outstanding in that they increased the percentage of large pores, and large aggregates. They also were the only two materials which produced significantly lower volume weights. The VAMA material appeared superior to the HPAN formulation. All treatments except the grape pomace, Lical and sawdust resulted in water permeability rates significantly higher than was found for the untreated soils. Exchangeable sodium content of the HPAlL-treated soil was approximately double that treated with any other material* This was due to the fact that the material used was the sodium salt of a hydrolyzed polyacrilonitrile* The exchangeable calcium and total cation exchange capacity was also sig­ nificantly higher where this material was used. It is believed that there was less chemical union between this material and the clay particles than was the case with the vinyl acetate-maleic acid polymer. Neither grape nor cover-crop yields showed significant differences due to treatment, except that nitrogen-treated plots produced higher cover-crop v yields. It is difficult in such an experiment to get consistent results, due to replacement of vines, frost injury, disease, etc. Such an experi­ ment should be run for at least five years to arrive at concrete results. Part B 1. Laboratory Experiment The effect of a number of different conditioner materials on aggregation and ion-exchange properties of four Ontario soils. From the time the field experiment was initiated in 1952 until the fall of 1953. & considerable number of new conditioner materials were re­ leased for experimental purposes. In order to evaluate these materials, four Ontario soil samples, and eight conditioner materials were used. Descrj-ption of Soils used. The Jeddo clay loam^ previously described, was used as one of the four soils. The others were a Brookston clay, a Burford loam, and a Guelph loam (28). The surface soil was used for this experiment. Brookston Clay. The Brookston series, as used in Canada, is the poorly drained member of the Huron catena. This series has a fairly 3^* high, organic matter content in the surface soil and itexhibits the characteristics of the Dark Gray Gleisolic soils* Profile Ac — 6-8 inches of dark gray brown clay; medium granular structure; sticky when wet; almost stone-free; pH 6.8 - 7.0. GA2— 6 inches of gray drab clay with yellow brown mottlings; fine to medium nuciform structure; sticky when wet; pH 6.8. G1 — 18 inches of gray clay with yellow brown mottling;coarse blocky structure; tough and plastic; pH 7*0. GrZ — 6-8 inches of gray to light gray clay; mottling less intense than in 01; very coarse blocky to massive structure; tough and plas­ tic; pH 7*2. C - Heavy calcareous clay till; gray to light gray in color; gritty; containing shale and limestone fragments; tough and plastic; pH ?.8. Burford loam. The Burford series is developed on well sorted gravelly materials derived largely from dolomitic limestone and contain­ ing smaller proportions of shaley and siliceous materials. The Burford is the well drained member of the catena of the same name. The profile exhibits well developed Gray-Brown Podsolic characteristics. Profile Ac - 6 inches of dark brown loam; medium crumb structure; friable consistency; medium organic matter content (under cultivation some areas have become moderately gravelly, particularly where the upper layers have been eroded); pH 6.5* A2 - 12-18 inches of light yellow-brown loam or sandy loam; medium nuciform structure; friable consistency; moderately stony or gravelly; pH 6*5 - 6.8. B - 6-18 inches of light brown gravelly clay loam; wavy horizon; medium nuciform structure; hard consistency when dry, sticky when wet; pH 7.0. C - Gray, gravelly outwash; well sorted; largely of dolomitic limestone origin, with smaller proportions of shale and sili­ ceous material; calcareous; pH 7*3. Guelph loam. Guelph loam exhibits the characteristics of the Gray- Brown Podzolic Great Soil Group. Its characteristics are illustrated in the following profile description. Profile AO - Accumulated layer of partially decomposed litter from deciduous trees. A1 — 0-4 inches dark grayish brown loam; fine granular structure; friable consistency; slightly stony; pH 6.9* A21- *4—12 inches pale brown loam; fine platy structure; very friable consistency; slightly stony; pH 6.8. A22- 12-14 inches gray loam; fine platy structure; friable consis­ tency; stonefree; pH 6.6 B - 14-24 inches brown clay loam; hard consistency; few to frequent stones; pH 7*0* C — Light gray loam till; medium nuciform structure; hard consisten­ cy; moderately stony; boulders vary from few to frequent; cal­ careous; pH 7*8* The relief consists of smooth slopes, and erosion is moderate* External drainage is good, and internal drainage is moderate* Conditioner Materials* The eight conditioners used were designated as follows: 1* VAMA (Krilium 6) 2* HPAN (Krilium 9) 3* IBMA (Krilium 212-100D) 4* BHQ 12582 5* BB Q ,12583 6* Conditioner B 7* Conditioner X 8* VTVA (Wettable) The VAMA and HPAN, as already described, are the calcium salt of a vinyl acetate-maleic acid polymer, and the sodium salt of a hydrolyzed polyacrylonitrile* The IBMA is the copolymer of isobutylene and the half ammonium salt—half amid of maleic acid* Its structural formula is probably: OEj H H H C C C C CEj H C-0 c»o nh 2 ONH The BBQ, 12582 and 12583 materials are both phenolformaldehyde capolymers* The conditioner B is similar to the IBMA. material* is the sodium salt of abietic acid in an unpurified form. material is the sodium salt of tall oil* Conditioner X The WVA vettable Method of treatment* The various conditioner materials were incor­ porated at a concentration of *02 percent, with 1000 gm* samples of soil which had been passed through a 1 mm* seive* After thorough mixing, the moisture content of the soil was raised to approximately field capacity* The soil samples were then scaled in two—quart containers and allowed to incubate at room temperature for one month* Following this, the samples were dried, and the percentage of water-stable aggregates was determined by the wet-seiving technique* Cation-exchange capacities were determined by the conventional ammonium acetate method and also by the conductance method proposed by Mortland and Mellor (18)* In this method the soil is saturated with barium chloride solution, then washed to remove excess chloride ion, and the barium soil is titrated with magnesium sulphate solution* There is a marked change in conductance once the end point is reached, all the barium having been precipitated as the sulphate. Since it was felt that these conditioners might be involved in anion exchange, a similar conductance method was used to determine the anionexchange capacity of the soils for the sulphate and chloride anions. The samples for sulphate anion measurement were saturated with magnesium sul­ phate and titrated with barium chloride solution to precipitate the sul­ phate as barium sulphate. To determine the exchange capacity for chloride, the sample was treated with barium chloride solution and titrated with a solution of silver nitrate* Besuits and Discussion The results of mechanical analysis by the pipette method (11) are shown in Table X. According to these results, the Brookston, Jeddo, Burford and Guelph soils would be classed respectively as a clay, clay loam, loam, and loam* In Table XI are shown the values obtained for cation—exchange capa­ cities with the four soils. While differences between untreated samples and the various treatments used are not consistent between the different soils, there do appear to be some differences that may be important in interpreting the value of these various conditioner materials. Conditioner X, for all four soils, produced an increase in exchange capacity. was also true for the WVA material except in the Guelph loam. This The Kri- lium 9 increased exchange capacity in every soil but the Burford. While there certainly is no evidence here to explain the nature of the soilconditioner effect, it would appear that cation-exchange studies over a range of concentrations of these materials on soils and clays might cast some light on this problem. The results of aggregate stability measurements are shown in Table XII, and in Figures 5t 6, 7, eu^d 8. Since the soils had been passed through a 1 mm. sieve prior to treatment, only the 0*5 mm# 0.25 mm. and 0.1 ram. sieves were used. In cases where treatments did not change the aggregate size distribution, or where the results were similar to those obtained for other treatments the data were not included on the graphs, to avoid confusion. The Brookston clay soil, a naturally well aggregated soil, was not appreciably changed by the conditioners. the VAMA had the greatest effect. However, the IBMA material and The Jeddo soil is naturally very poorly aggregated. Its stable aggregate percentage greater than 0.1 mm. was only slightly more than half that of the Brookston clay. With the Jeddo, the IBMA was far superior to any other material. VAMA was in second place, with Condi­ tioner B also quite effective. HPAN and Conditioner X produced slight increases in stable aggregates. The other materials, WVA, and the two BBQ preparations gave little or no effect. On the Burford loam, the response was not so great. VAMA were again in first and second place. The IBMA and HPAN, WVA, Conditioner B, and Conditioner X gave smaller responses. In the Guelph loam there was marked response to the conditioner applications. All treatments except the two BRQ materials resulted in a marked increase in stable aggregate size. The IBMA and VAMA were again far superior to any of the other materials. To summarize, the maleic acid polymers were far superior, under the conditions of this experiment, to any other material used in in­ creasing the percentage of water-stable aggregates* The polyacryloni- trile formulation, the salt of abietic acid, and the tall oil prepara­ tion produced some effect, the magnitude of their effectiveness depending on the soil. The phenol-formaldehyde copolymers were of little or no value in increasing the percentage of water-stable aggregates. With regard to the anion-exchange measurements for the chloride and sulphate anions, none of the soils used were able to adsorb these anions whether treated with conditioner or not. TABLE X MECHANICAL COMPOSITION OF THE FOUR SOILS USED AS DETERMINED BY THE PIPETTE METHOD OF ANALYSIS EXPRESSED AS PERCENTAGE Particle Size, microns Soil 20 20 10 5 2 1 Brookston Clay ~ 29.7 70.3 62.2 52.1 40.3 34.7 Jeddo Clay Loam 45-3 54.7 54.3 46.7 35.6 34.5 Burford Loam 66.9 33.1 29.9 23.1 19.9 19.9 Guelph Loam 65*4 34.6 32.3 26.2 19.2 15.6 41. TABLE XI THE EFFECT OF EIGHT CONDITIONER MATERIALS OH THE CATION-EXCHANGE CAPACITY, EXPRESSED IN MILLIEQUIVALENTS PER 100 GRAMS SOIL, OF FOUR SOILS USED Treatment Soil Samples Brookston Jeddo Guelph Burford Check 34.8 26.9 14.0 15.5 Conditioner X 35.6 27.3 14.0 18.9 BRQ, 12582 34.6 28.3 14.2 16.4 BRQ, 12583 34.9 25.4 14.2 18.6 WVA wettable 34.9 25.7 14.1 18.2 IBMA 34.8 24.6 14.4 14.4 VAMA 34.7 27.9 15.2 14.0 Conditioner B 34.6 27*5 14.5 15.5 HPAN 34.8 29.0 14.1 14.1 TABLE XII PERCENT WATER STABLE AGGREGATES GREATER THAN 0*1 mm. IH POUR SOILS TREATED WITH EIGHT CONDITIONER MATERIALS Sreatment Soil Samples Brookston J eddo Guelph Burford Check 68.8 39.6 74.8 62.8 Conditioner X 82.8 47.6 76.0 68.8 BEQ, 12582 82.4 46.0 ?4.4 64.4 BBQ, 12583 81.0 40.4 70.0 68.0 VTA wettatle 82.8 41.2 78.8 70.4 I3MA 92.0 79.6 92.4 8 3 .6 TAKA 85.2 61.2 90.0 77.2 Conditioner B 83.6 57.2 80.8 73.2 HPAH 84.8 41.2 82.0 74.0 — ©--- ©---- Check ----------- VAMA H----- 1----1- HPAN *---- #---- * IBMA ■S----S --- ^ Conditioner B -J— ©— f— ©— f- Conditioner X 0L 0.1 I---------- I---------- 1---------- 1 0.2 0.3 0.4 0.5 Aggregate size - mm Figure 5 Cumulative percent aggregation of a Brookston clay soil treated with a number of organic amendments 75 Aggregation - percent 50 9 — Check 25 VAMA HPAN ^ — Conditioner B ^— 0— f— Conditioner X 0L 0.1 0.2 0.5 Aggregate size - mm Figure 6. Cumulative percent aggregation of a Jeddo clay* loam soil treated with a number of organic amendments / o o .1 — -» I 0.2 I 0.3 Check ------ VAMA. — IBMA — Conditioner X ... , I__________ I 0.*f 0.5 Aggregate size — mm. Figure 7 Cumulative percent aggregation of a Burford loam soil treated with a number of organic amendments. k6. Aggregation - percent 75r Check VAMA HPAN IBMA ■6— Conditioner B — H Conditioner X 0.2 0.3 0.4 0.5 Aggregate size - mm Figure 8. Cumulative percent aggregation of a Guelph loam soil treated with a number of organic amendments 2m The effect of conditioner concentration on the ion—exchange properties of Wyoming bentonite, fcaolinite, and a Jeddo 31ay loam Soil. After establishing the value of the various conditioner materials available on the basis of their effect on stable soil aggregates, it appeared desirable to try the effect of the better materials on the cation-exchange capacities of typical clay minerals# Also, although there were none of the soils that exhibited a capacity to adsorb small anions, it was desired to measure the effect of conditioner treatment on the anion exchange capaci­ ties for phosphate ions, a relatively large anion# Accordingly, the IBMA. material, the VAMA, and Conditioner X were applied at three concentrations to Wyoming Bentonite, kaolinite, and the Jeddo clay loam soil# The Condi­ tioner X was used in addition to the other two, since other workers (10) have found it more effective than the work previously reported in this thesis would indicate* The concentrations used were 0#02 percent, 0*1 percent, and 1.0 percent* Water solutions of the first two materials and a water suspension of the Conditioner X were applied to the soil and clay suspensions* The resulting mixtures were allowed to stand for forty- eight hours before determinations were made# Results and Discussion It is interesting to note (Table XIII) the way in which the several concentrations influenced the cation-exchange capacity for the ammonium ion of the bentonite and kaolinite# With the montmorillonitic clay, very low concentrations of IBMA resulted in a tremendous increase in cationexchange capacity. With increasing concentration of the conditioner, the exchange capacity decreased, although even at 1.0 percent concentration, it was slightly higher than in the bentonite alone* Were there no in­ teractions, one would expect the exchange capacity of the clay—conditioner mixture to increase, the increase being greatest at the highest condi­ tioner content* With the IBMA, all concentrations decreased the cation—exchange capacity of the bentonite mixture, the decrease being greatest at the highest conditioner concentration. This might be explained by stating that the conditioner anion, through a cation linkage, occupies some of the exchange sites on the clay* Heavier applications would result in a further decrease until all exchange sites available were occupied; there were no more suitable cations to act as connectors; or until steric hin­ drance prevented the large conditioner anions from filling any further exchange positions* The Conditioner X at low concentrations also increased the exchange capacity, but decreased it as concentrations were increased* In the case of the kaolinite, all concentrations of all materials produced an increase in exchange capacity* It appears quite possible here then, that the effect of conditioner plus clay is additive, and that there is little if any interaction. With regard to the Jeddo soil, low concentrations of YAMA produced disproportionate increases in exchange capacity. The IBMA, as in the case of the montmorillonite, caused a reduction in cat ion-exchange at low concentrations. At the 1*0 percent concentration, however, the ex­ change capacity was greater than that of the untreated soil* This is I*) not surprising, since the clay content of the soil is about 35 percent* Assuming that most of the clay is of the montmorillonitic type, the one percent concentration would be approximately equivalent to a three per­ cent concentration with regard to the clay. The results obtained for the Jeddo soil with Conditioner X show a consistent increase in exchange capacity with increasing concentration. This may indicate the absence of any appreciable interaction. The anion-exchange capacities for the phosphate ion, as determined by the method of Piper (2*0, were not affected by the treatments either for the clays, or the soil. This experimental evidence seems to indicate quite conclusively that the conditioner action in some way alters the cation-exchange the clay. 6f 3* Catioxwexchange properties of Wyoming bentonite end kaolinite treated with a wide range of conditioner concentrations* Following the work outlined in 2, it seemed desirable to fur­ ther studies of conditioner materials at a wide range of concentrations in combination with bentonite, to determine the extent of the changes in base—exchange capacity* If possible, it appeared desirable to deter­ mine the exchange capacity by some method other than the conventional ammonium acetate method* method* There were two reasons in favor of a different The first is that it is very difficult to make a determination of exchange capacity of bentonite by the conventional ammonium acetate method, because of the physical nature of the bentonite* The second* more important reason is that the results obtained with the ammonium ion might not be the same as would be obtained with other cations* To eliminate the possibility that the associated conditioner cations and adsorbed clay cations might be responsible for any effect measured, the acid forms of the VAMA., IBMA. and abietic acid were obtained, courtesy of the Carbide and Carbon Chemical Corp. A hydrogen^spfcor&iied clay was prepared by electrodialysis* Once the conditioner acids and acid clay were available, a suitable method hari to be devised to measure the extent of cation adsorption* conductance method (35) seemed well-suited to this problem. A Preliminary experiments indicated that this method would work very well, in titrating the acid clay with dilute NaOH and Ca(0H)2 solutions. Since the conditioner acids were not water-soluble, it was necessary to use an alcohol solution of the VAMA. and abietic acid, and an acetone solution of the IBMA. One percent solutions of H—, Ha*-, and C&- saturated clay and 0*1 percent solutions of the conditioners were prepared. Since the VAMA material is the most widely known and used conditioner, most of the work was with this material. Clay suspensions containing VAMA at concentrations ranging from 0.002 percent to 25 percent were prepared, using the E-clay. CaCOH)^. These mixtures were titrated with .012J HaOH .0*HI Similar titrations were carried out with the IBMA and Abietic aqids using concentrations from 0.1 to 10.0 percent. In addition to the above determinations, the clay acid was titrated with conditioner acid of the three conditioner materials. Also, the Na- and Ca** clays were titrated with conditioner acids. To establish whether the observed reactions were confined to 2:1 ex­ panding—lattice type clay minerals, a H-saturated kaolinite was treated with VAMA and titrated with the NaOH solution. Titration values were obtained for both conditioners, and for ui>* treated clay. These values were used in arriving at the theoretical val­ ues that should exist were there no clay—conditioner interactions. Ioa-mobility measurements were also made on a number of H-bentoniteVAMA mixtures. Results and Discussion la Figures 9 and 10 are shown the effect of conditioner concentration on the cation—exchange capacity of the clay systems used. It will be ob­ served that, at very low concentrations of VAMA (of the order of .002 per— v cent) there was a marked decrease in exchange capacity. This was followed by a rather sharp increase at about .05 percent conditioner concentration. Following this abnormally high value, the exchange capacity dropped, and continued low with further increases in conditioner concentration* relative to the theoretical value. The theoretical value was obtained simply by adding the exchange capacity of the untreated H-clay to the titration value I obtained for the various amounts of conditioner acid. . In Figure 11 are shown typical titration curves with UaOH for the clay conditioner systems. It was observed, that with no conditioner present and at "low conditioner concentrations, the angle at the equivalence point was quite acute. As the concentration of VAMA was increased, the angle became less acute, uhtil at concentrations of this material above 15 percent, it was not possible to establish a definite endpoint. In Figure 12 is shown a typical titration curve for the conditioner material alone.Figures 13 and 1*1- show the effect of conditioner on a IL*clay titrated with Ca(0H)£. It is again apparent that at very low concentrations there was a rapid decrease in exchange capacity, followed by an increase, which again was followed by a decrease. Low values (below the theoretical) were obtained until about 20 percent conditioner concentration, at which point the actual, and theoretical values practically coincided. 55.0 •p i —i o U-\ o m3 QQ-f jad "bam - JLnovdvv e3ueqo»-uof^so Effect of low concentrations of VAMA on the cation-exchange capacity of H-bentonite for sodium ion -p Figure 9. »-i Figure 10. Effect of high concentrations of VAMA on the cation-exchange capacity of H-bentonite for sodium ion 55. ■vsS 001 jsd 'bsra - jC^mwIbo aSasqoxa-aoT^BO 500 r Jigtire 11* Typical titration curves of E-bentonite treated with VAMA. and titrated with NaOH* 56 0001 x enrc£° — 9Ot[eq.SfS0g Figure 12, Typical titration curve of VAMA titrated with NaOH - 0,01 gm. 900- 57, 000T x sniqo - sotreq.sTS9H 59 - o cv UN H C CD 0 p CD -p ft 1 3 P oo v \ o o vr\ qqj J9d o O r-t r-i •hew - xo^dBO ©Sireipxa-uoT'veo The titration curves at low conditioner concentrations were similar with Ca(OH)£ to those obtained, with NaOH* However, with increasing con- centration of conditioner, instead of the points becoming almost linear on the two sides of the equivalence point as they did with the sodium system, two distinct end points appeared* This is illustrated in Figure 15# It t may be noted that the equivalence point on the pH curve approximates the second endpoint on the conductance curve* While no data on the IBMA are presented here, it was observed that the material did behave similarly to VAMA* The slight dissociation of the IBMA and ABA materials, however, made it difficult to get consistent re­ sults* For this reason, data are not presented here on these two materials* Since both materials are maleic acid polymers, it was hot^felt necessary to conduct as detailed a study of clay-IBMA systems as was done with the VAMA* With regard to the ABA (abietic acid) there was no evidence of interaction, the results obtained approximating the theoretical values* In Figure 16 are shown the values obtained by treating B-kaolinite with VAMA and titrating with HaOE* All values were practically identical to the theoretical values, indicating the lack of reaction with this material* In Figure 17, the titration curve of H-clay titrated with VAMA is shown. points. It will be observed that there are two completely separate end­ This was also observed when the H-clay was titrated with the IBMA, (Figure 18)* Titration curves of the Ha-clay and Ca-clay with VAMA also show two separate endpoints, Figures 19 and 20, although these endpoints do not coincide between the three types of clay systems. 200 r O o o CM O r-l O O o o NO o o o o CM O* o o 0001 x enrqo - o o ©0Treq.s*fS9a id »§ s w o "of 0 CM "S © CO CO 1 •©H Typical pH and conductance titration curves for H-benfconite treated with twelve percent VAMA. and titrated with Ca(0H)P* ON Pigure 15* 61 *8, C'NCO O 62. vO rH