REMOTE STORAG URN BOX to remove this c TO AVOID FINES return on or before date due. PLACE IN RET E RSI: heckout from your record. DATE DUE DATE DUE DATE DUE P 3‘, - {, I. fffi’ ‘- I ‘ I ,‘ w J “‘3 I»; h “.4/ 2/17 20: Blue FORMS/DateDueForrns_20W.mdd - pg‘S _—-—- USE OF DETROIT SEWAGE SLUDGE COMPOST FOR SOD PRODUCTION ON TWO MINERAL SOILS BY Mark J. Carroll A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Crop and Soil Sciences 1982 ABSTRACT USE OF DETROIT SEWAGE SLUDGE COMPOST FOR SOD PRODUCTION ON TWO MINERAL SOILS BY Mark J. Carroll Many metropolitan areas in the United States, forced by environmental and/or economic limitations have considered increasing land application of sewage sludge material. The use of composted sewage sludge is often preferred to the use of other types of sludge material because of the ease in handling the finished product and the lower odor and pathogen content. The possibility of heavy metal uptake into the food chain, caused by compost land application, can be circum- vented by applying compost to a non-edible food crop, such as turf. Sod farms, which are often close to metropolitan areas have been considered ideal sites for land application of sewage sludge compost. The objectives of this study were 2 fold: l) to eval- uate the impact of Detroit sewage sludge compost on turf growth and sod formation and: 2) to determine the influence of Detroit sewage sludge compost on select soil physical and chemical properties. Field plots were established to Kentucky bluegrass (Poa pratensis L.) on an Oakvile fine sand and a Pewamno sandy clay loam soil in southeastern Mark J. Carroll Michigan. Treatments consisted of O, 84, 168, 252 or 336 mt/ha compost, incorporated to a depth of 10 or 20 cm. The effect of compost on seed germination, N content of clippings and dry matter production of Manhattan perennial ryegrass (Lolium perenne L.) was evaluated in greenhouse pot studies. Incorporation of compost delayed emergence and early establishment of Kentucky bluegrass under dry soil condi- tions. At a given rate of compost addition, the 20 cm depth of incorporation minimized the inhibitory effect of the compost when compared with the 10 cm depth. On the Oakville soil, throughout the first growing season following treat- ment, chlorotic turf growth was observed in compost-amended plots. No chlorotic growth was observed the second year. Turf quality of the compost-amended plots was not signifi- cantly different than that of the check plots during the first growing season following compost incorporation. How- ever, in the second growing season, compost-amended plots in general, had significantly higher turf quality than the check plots. Seed germination of Manhattan perennial ryegrass was substantially reduced under high irrigation conditions at a 75% (by volume) compost rate on both soils. Under low irrigation conditions, 50 and 75% compost resulted in a substantial reduction in ryegrass seed germination on the Oakville soil. Mark J. Carroll Compost had no significant effect on sod shear strengths in the field, but did result in increased dry matter produc- tion. In the greenhouse, when no supplemental N was added, increasing rates of compost up to 270 mt/ha increased dry matter production of Manhattan perennial ryegrass. When supplemental N was added, there was no consistent trend. The presence of heavy metals in the compost did not appear to present a limitation to sod growth at the rates applied in this study. Cadmium and Ni were found to increase significantly in the clippings with compost incorporation, but the increases were not great enough to affect growth. Soil physical properties improved with compost incor- poration. On both soils, compost increased saturated hydraulic conductivity, water holding capacity and plant available water while decreasing soil bulk density. On the Pewamo soil, compost increased the infiltration of water into the soil. Application of Detroit sewage sludge compost to mineral soils does not appear to adversely affect sod growth. The value of the compost as slow release fertilizer and as a soil amendment was readily apparent in this study. To my sisters Diane, Donna, and Lisa for their love, support and encouragement. ii ACKNOWLEDGEMENTS The author wishes to express his deepest gratitude and appreciation to his major professor, Dr. Paul E. Rieke, for his guidance, interest and patience throughout this investigation. Appreciation is also extended to Dr. L. W. Jacobs, Dr. E. A. Erickson and Dr. J. M. Vargas, for their advice and presence on the author's graduate committee. The author is grateful to, Mr. R. Bay, for his assist- ance in the field, and to Ms. R. Kranz, for analyzing soil and tissue samples on the Plasma Emission Spectrometer. Acknowledgement is also extended to the Department of Crops and Soil Sciences for its financial support of this investigation. iii TABLE OF CONTENTS LIST OF TABLES. LIST OF FIGURES INTRODUCTION. LITERATURE REVIEW . A. D. Composting of Sewage Sludge 1. Types of sludge. . 2. Methods of composting. Constraints of Sewage Sludge Compost Use. 1. Human concerns . . . . . 2. Plant concerns Influence of Compost on Soil Properties 1. pH, organic matter, and cation exchange capacity . . 2. Soil physical properties Effect of Compost on Turfgrass. MATERIALS AND METHODS A. Field Operations. Site Location. 2. Compost. 3. Plot design and treatment. 4. Establishment. 5. Visual observations. . 6. Tissue and soil collection . 7. Sod strength . . . . 8. Physical measurements. Greenhouse Studies. 1. 2. L l. 2. S H Seed germination . . . Turf growth and nitrogen uptake. aboratory Analyses . . . Soil and tissue samples. Soil cores tatistical Analyses. iv RESULTS AND DISCUSSION A. Field Observations 1. Establishment 2. Turf color and quality. Tissue and Soil Samples. 1. Soil macronutrients 2. Tissue macronutrients 3. Heavy metals. . 4. Sod strength and field clipping weights Greenhouse Studies 1. Seed germination. . . 2. Clipping weight and N study . Soil Physical Properties 1. Bulk density, saturated water flow, wood chips concentration . 2. Field infiltration. 3. Soil moisture . 4. Soil compaction . SUMMARY AND CONCLUSIONS. LITERATURE CITED . Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. LIST OF TABLES Characterization of the soils at the two sod farm plot locations. Analysis of the sewage sludge compost applied to the two sod farms Treatment applied to Huron and Waltz Green Acres sod farms August 21, and 22, 1979 . . . . Effect of compost on the rate of development of Kentucky bluegrass sod on the Oakville soil Effect of compost on the rate of development of Kentucky bluegrass sod on the Pewamo soil Effect of compost on the color of Kentucky bluegrass sod during the 1980 growing season on the Oakville soil. Effect of compost on the color of Kentucky bluegrass sod during the 1981 growing season on the Oakville soil. Effect of compost on the color of Kentucky bluegrass sod during the 1981 growing season on the Pewamo soil. Effect of compost on the quality of Kentucky bluegrass sod during the 1981 growing season on the Oakville soil. Effect of compost on the quality of Kentucky bluegrass sod during the 1981 growing season on the Pewamo soil. Extractable macroelement and pH levels of an Oakville fine sand soil amended with various compost treatments on August 21,1979 and samples July 21, 1980, September 19,1981 . vi Page 19 21 22 35 36 39 4O 42 43 45 47 Page Table 12. Extractable macroelement and pH levels of a Pewamo sandy clay loam soil amended with various compost treatments on August 22,1979 and sampled July 7, 1980, August 21,1981. . . . . 48 Table 13. Macroelement concentrations of Kentucky bluegrass clippings harvested July 31, 1980 from the Oakville soil. . . . 51 Table 14. Macroelement concentrations of Kentucky bluegrass clippings harvested July 29, 1981 from the Pewamo soil. . . . . 52 Table 15. Microelement levels of an Oakville fine sand soil amended with various compost treatments on August 22, 1979 and sampled July 18, 1980. . . . . . . . . 54 Table 16. Microelement levels of an Oakville fine sand soil amended with various compost treatments on August 22, 1979 and sampled September 19, 1981 . . . . . . 55 Table 17. Microelement levels of a Pewamo sandy clay loam soil amended with various compost treatments on August 22, 1979 and sampled on July 7, 1980. . . . . . 57 Table 18. Microelement levels of a Pewamo sandy clay loam soil amended with various compost treatments on August 22, 1979 and sampled on August 21, 1981 . . . . 58 Table 19. Microelement concentrations of Kentucky bluegrass clippings harvested July 31, 1980 from the Oakville $011.. . . . 59 Table 20. Microelement concentrations of Kentucky bluegrass clippings harvested September 6, 1981 from the Oakville soil . . . . 60 Table 21. Micronutrient concentrations of Kentucky bluegrass clippings harvested July 29, 1981 from the Pewamo soil . . . . . 61 Table 22. Dry clipping weights of Kentucky blue- grass harvested from the two sod farms in the summer of 1981.. . . . . . . . 63 vii Table Table Table Table Table Table Table Table 23. 24. 25. 26. 27. 28. 29. 30. Sod shear strength and percent soil organic matter determined on the Pewamo and Oakville soils. Dry clipping weights of Manhattan perennial ryegrass grown in the green- house in an Oakville fine sand soil amended with compost at 3 monthly nitrogen application rates Dry clipping weights of Manhattan perennial ryegrass grown in the green- house in a Pewamo sandy clay loam soil amended with compost at 3 monthly nitrogen application rates Effect of compost and nitrogen treat- ments on the percent nitrogen in Manhattan perennial ryegrass clippings after an incubation period of 14, 18 or 34 weeks. . . . . . . . . . . . . Soil physical determinations made on cores collected from the field in late summer of 1981. The effect of compost on infiltration of 2 soils 2 years after compost incorporation. . . . . . . The effect of compost on the water retention characteristics of 2 soil types. Decrease in soil bulk density of a compost amended Pewamo sandy clay loam soil due to a compactive force of 4.00 bars . . . . . . . . . . . . . . viii Page 65 72 73 74 77 82 85 90 Figure Figure Figure Figure Figure Figure Figure LIST OF FIGURES Page Number of Manhattan perennial rye- grass seeds germinated per pot in an Oakville fine sand soil at 2 irrigation and 4 compost levels replicated 4 times. . . . . . . . . . . 67 Number of Manhattan perennial rye- grass seeds germinated per pot in a Pewamo sandy clay loam soil at 2 irrigation and 4 compost levels replicated 4 times. . . . . . . . . . . 68 The effect of compost on soil bulk density of an Oakville fine sand and Pewamo sandy clay loam when incor- porated to a depth of 20 centimeters. . 78 The effect of compost on saturated hydraulic conductivity of an Oakville fine sand and Pewamo sandy clay loam soil when incorporated to a depth of 20 centimeters. . . . . . . . . . . . . 79 Amount of water infiltrated over a 3 hour period on a Pewamo sandy clay loam soil as influenced by compost incorporation . . . . . . . . . . . . . 83 Average percent moisture, by weight, of an Oakville fine sand soil amended with 4 rates of compost to a depth of 20 centimeters. . . . . . . . . . . . . 86 Average percent moisture, by weight, of a Pewamo sandy clay loam soil amended with 4 rates of compost to a depth of 20 centimeters. . . . . . . . . . . . . 87 ix INTRODUCTION Solids removed from the wastewater treatment processes constitute what is commonly referred to as sewage sludge. Sewage sludge annually accounts for approximately 0.5 percent of the total organic waste produced in the United States.49 Recent improvements in wastewater treatment processes have resulted in increased collection of dry solids. It has been projected that by the year 1985 over 9.1 million metric tons of dry sewage sludge will be produced annually in this coun- try.so Currently the commonly used methods of sewage sludge disposal (ocean dumping, landfilling, incineration) are in- creasingly being restricted due to specific environmental legislation (i.e., Clean Water Act of 1972, Clean Air Act of 1967). Large metropolitan areas, forced to seek economically feasible and environmentally sound alternative methods of sewage sludge disposal, have considered increasing land application of sewage sludge material. From an economic point of view, one of the primary con- cerns associated with land application of sewage sludge is the cost involved in transporting the material from the metropolitan area to the application site. Sod farms, because of their close proximity to metropolitan areas, have been considered ideal sites for land application of sewage sludge. The use of composted sewage sludge compared to other types of sludges is preferred because of the ease in handling the finished product. Liquid and raw sludges require that the material be transported in sealed trucks and that the material be incorporated immediately upon application to the field. Composted sludge on the other hand requires no special trans- portation or application equipment and can be incorporated any time after it is applied to the field. The use of composted sewage sludge may be of benefit to the sod grower. Inherent in the sod farming operation is the removal of a small portion of the existing soil when each successive crop of sod is harvested. With the regular removal of soil, inevitably part of the productive potential of the soil is lost. On mineral soils, where the productive depth of the soil may be limited, soil removal is of particular concern. Application of sewage sludge compost as a soil amendment may aid the sod grower in returning lost produc- tivity by improving soil physical properties and by restoring removed nutrients and organic matter. Additionally diluting the soil.with compost may reduce the amount of soil lost each time sod is harvested. Certain limitations (metal loading of soils) exist when compost applications are to be made to lands under sod produc- tion. These limitations require that preliminary work be performed to determine if land application constraints must be placed on the utilization of compost for turfgrass sod produc- tion. The purposes of this investigation were two fold, 1) To evaluate the impact of Detroit sewage sludge compost on turfgrass growth and sod formation and, 2) To determine the influence of Detroit sewage sludge compost on select soil physical and chemical properties. LITERATURE REVIEW A. Composting of Sewage Sludge 1) Types of sludge Sewage sludges vary widely in composition and properties depending on the treatment process and the source of the sew- age. On the basis of the source of sewage, sludges can gener- ally be classified as either industrial or residential. Typically industrial sludges are characterized by high concen- trations of one or more heavy metals while residential sludges are usually low in all heavy metal concentrations. 0n the basis of the wastewater treatment process, sewage sludges are generally classified into 3 groups; raw, digested and acti- vated.41 In the wastewater treatment process all sludge types undergo primary treatment. In primary treatment, sewage is passed through a series of screens and chambers to remove large objects and to allow coarse material such as sand and gravel to settle out. Upon passing through the screens and chambers the sewage is directed to settling tanks were it is allowed to settle out for a period of 90 to 120 minutes.47 The material.collected from this sedimentation period, if it undergoes no further treatment, is referred to as raw or undigested sludge. Raw or undigested sludge is unacceptable for use on most agricultural land because of the objectional odor and the high pathogen risk. Vegetables grown in soils where raw sludge has been applied have resulted in outbreaks of Typhoid Fever, Ascariasis, Amoebiasis, Bacillary Dysenteny, Enteric Fevers, 12 and Diarrhea. Heat drying or liming raw sludge to a pH of 11.5 can substantially reduce the pathogen content of the sludge.27’ 60 Injection of raw sludge into the soil can partially circumvent the objectional odor associated with land application. Material that is allowed to undergo anaerobic decomposi- tion following primary treatment and is subsequently either dewatered, partially dried, or allowed to remain in liquid form (2-10 percent solids) is commonly referred to as digested 41 During anaerobic decomposition, denitrification of sludge. inorganic N occurs which lowers the amount of readily available N contained in this type of sludge. The objectional odor of digested sludge, while noticeable, is not as strong as the odor of raw sludge.60 Activiated sludge is created when raw sludge is placed in aerated tanks with freshly processed activiated sludge for a period of 4 to 6 hours. The material which settles out, after flocculation of the suspended colloidal particles occurs, constitutes the activated sludge. Activated sludge, if it is dewatered, dried and then ground, can serve as a source of 48 fertilizer. More commonly activated sludge undergoes additional treatment for further stabilization, such as aerobic or anaerobic digestion. 2) Methods of composting Inorganic forms of N can be stabilized while odors and pathogenic organisms can be reduced to the point of being con- sidered a negligible concern by the composting of sewage 60 sludge. A method widely referred to as the "Beltsville Aerated Pile Method" has been developed which allows for the composting of either raw or digested sewage sludge.25’ 49 Summarizing the "Beltsville Aerated Pile Method" as explained 49 the process consists of mixing partially by Parr and Willson, dewatered sewage sludge (approximately 22 percent solids) with a bulking material such as wood chips. Usually 2 to 3 parts wood chips are mixed together with 1 part sludge. After mixing, the pile is allowed to stand for 3 weeks under forced aerated conditions. The wood chips are added to: 1) provide the necessary structure and prosity to accomodate forced aeration, 2) to lower the moisture content of the biomass, and 3) to provide the proper carbon to nitrogen ratio (CzN) necessary for maxi- mum efficiency of composting. In addition to moisture, oxygen, and the proper C:N ratio; temperature, pH, and particle size of the sewage sludge affect the speed at which the composting process takes plaCe., The optimum range for each of these 51 factors is discussed in greater detail by Poincelot and summarized by Parr and Willson.49 After 21 days of composting in the aerated pile, 2 possible Options are available. One option calls for immediate drying of the pile with subsequent removal of the wood chips. Follow- ing the removal of the wood chips, a 30 day "curing" period takes place which ensures that any remaining pathogens are destroyed. The second Option calls for the 30 day "curing" period to take place before the wood chips are removed. This second option is followed when it is expected that the compost pile will be exposed to inclement weather. An alternative method, the "Windrow Method" can also be 23 This method does used for the composting of sewage sludge. not utilize a closed forced aeration system but instead relies upon the more labor intensive operation of turning the pile every several days to insure aerobic/thermophillic composting of the sludge. Limitations of the "Windrow Method" are that raw sludge cannot be composted by this method and that the time for composting digested sludge is longer than that for the "Beltsville Aerated Pile Method". In addition, composting by the "Windrow Method" requires more area to compost a given amount of sludge. B. Constraints of Sewage Sludge Compost Use 1) Human concerns Pathogenic concerns of sludge compost appear.tobe limited to the composting operation itself. Certain species of thermophilic Actinomycetes along with the fungus Aspergillus fumigatus, which grow in self heating organic matter, may pose a health hazard to indivdiuals who work in composting opera- 12 tions. Thermophilic Actinomycetes have been increasingly linked with the disease "Farmers Lung" while Asperigillus fumigatus has been implicated in large fungal growths in the lungs of allergy prone individuals, As a precautionary measure, it has been recommended that individuals who have had a history of lung related problems, or those who are on a medical program which requires the use of insulin, antibiotics, or corticos- teriods avoid working at sludge composting sites. The most prominent concern associated with land applica- tion of compost has been the potential for increased uptake of metals into the food chain. Application of sewage sludge and sludge composts to forage crops has resulted in signifi- cant increases in the levels of Cd, Cr, Cu, Mn, Pb, Zn, and Fe.9’ 37, 43, 46, SS, 57, 58 In compost treated pastures, significant increases in the Fe levels of various cattle tissues has been reported along with small consistent Cd in- creases (though not statistically significant) in cattle kidneys.58’ 59 Chaney has suggested that food chain accumulation of trace metals is not a problem since the amount that is normally toxic to plants is less than the concentrations that are harm- 'ful to animals or humans.15“ One metal that is an exception to this, however, is Cd. Cadmium is not essential to either plant or animal nutrition. Chronically elevated levels of Cd in animals have been linked to renal and reproductive dysfunc- tions.3 One way to possibly insure that Cd will not be a potential food chain hazard on acid soils, is to limit sludge compost applications on agricultural lands to those composts which have 16 This recommendation has a Cd/Zn ratio of less than 0.01. been made on the basis that Zn toxicity would occur to the crop before the Cd content of the crop could rise to a level that would constitute a health concern. 2) Plant concerns Plant response to compost addition is dependent on several factors. Among these are the amount and composition of the compost added, method of.compost addition (topdressing versus soil incorporation), soil type, plant species, and soil manage- 59,60 ment practices. Numerous instances of yield increases and decreases brought about by sludge addition have been re- 17 29, 34, 43, 55, 57 ported. ’ Positive yield responses can most often be attributed to increased N, P, and/or K supplied by the sludge material while negative yield responses are most 18 Typi- often linked to toxic concentrations of trace metals. cally, sludge composts contain rather low amounts of macro- nutrients. For example, the N-P-K analysis of a compost ‘produced from undigested sludge at Beltsville was found to be 1.6-1.0-o.2.32 10 COpper, Zn and Ni are considered to be the trace elements which will most likely cause toxicity from sludge applications while Cd, Cr, Mn, Hg and Pb are regarded as less of a potential 62 problem. Copper, Zn, and Ni are believed to cause crop injury 60 In the case of Ni there is a by inducing a Fe deficiency. marked difference in the tolerance of various crops to this metal which has been attributed to differences in the Fe/Ni ratios of the plants. Low Fe/Ni ratios appear to make the plant susceptible to N1 toxicities.44 In oats (Avena sativa L), there is evidence that suggests Ni may increase the rate 63 In of Fe uptake but inhibit its metabolism in the plant. general, at the same concentrations, Ni is four to eight times as toxic as Zn, while Cu is considered to be twice as toxic as Zn.60 The relative tolerance of plant species to metal toxici- ties has been reviewed by Chaney.16 In general, most vege- table cr0ps have been listed as sensitive to very sensitive in their ability to withstand elevated tissue metal levels while agronomic crops such as small grains, corn and soybeans have been shown to have a.moderate tolerance to elevated metal levels. Turf and forage type grasses have the ability to tolerate higher tissue metal levels than agronomic crops. The addition of compost in some cases has been shown to reduce the seed germination of certain crops. Mays et a1.,43 20 and Duggan and Wiles working with municipal compost have- attributed the poor seed germination of corn to the difficulty 11 in establishing a firm seed.bed due to the bulkiness of the 26 have found that compost additions compost. Epstein et al., of 160 and 240 metric tons/hectare (mt/ha) result in high soil salinity and chloride levels which could affect seed germina— tion. In order to prevent a reduction in seed germination to salt sensitive cr0ps, it has been recommended that compost applications be made 1 to 2 weeks prior to planting.32 C. Influence of Compost on Soil Properties 1) pH, organic matter and cation exchange capacity The actual availability of sludge born-metals is often less than expected.17’ 30’ 36 The availability of Cr, Cu, Zn and Ni inorganic salts compared to the availability of these metals when mixed with a sewage sludge prior to addition to a 17 Treat- Warsaw sandy loam was examined by Cunningham et a1. ments involving inorganic salts without sludge resulted in lower yields, and in general (Ni being the exception), higher tissue metal concentrations in rye (Seceale cereale E.) than the equivalent sludge treatments. Similar results involving cadmium.applied as cadmium acetate have revealed that cadmium is clearly more available from the salt source than from the 36 sewage sludge source. In general, metals in composted sludge are less available to plants than metals in digested sludge.38 Effects on soil cation exchange capacity (CEC), Organic matter and pH, all of which can be influenced by sludge or-compost additions, may account for the decreased availability 12 of the sludge born metals.2’ 20’ 26’ 29’ 45’ 55’ 58 The pH changes that occur in the soil alter metal avail- ability by affecting the solubility of the various metals. Liming of soils prior to sewage sludge additions has been shown to lower soil extractable metal levels and plant uptake of 34 The effect that sewage sludge has on pH is often 18 metals. dependent on the type of sludge added. Liquid sewage sludges which often contain considerable amounts of NH4-N can cause a short term drop in soil pH due to the intense nitrification 18, 37 that occurs. Composted sludge, on the other hand, which is resistant to rapid N mineralization and usually has a pH between 6.5 and 7.3, generally induces a liming effect when 2, 20, 45, 57 added to acid soils. Municipal compost has been shown to buffer the acidifying effects of repeated applications of ammonium nitrate sulfate (30-0—0 plus 5% S) over a 4 year 0 The EPA has recommended that soils to which sludge 21 period.2 is to be added should have a pH maintained at 6.5 or above. The increase in CEC that accompanies compost additions is invariably due to the presence of organic matter (typically 50% by weight on dry solids basis) in the compost.45 Duggan 20 and Wiles have found that after 4 years of annually applying 448 mt/ha compost to a loam soil, the organic matter content of the soil rose from 1.4 to 13.1 percent. Through chelation affects and by forming complexes with metals, organic matter aids in preventing eXCessive metal uptake by’plants.38 38 Kirkham has listed the tendency of organic matter to bind 13 with metals as Cr+3 > Fe+3 > Cu+2 :> Ni”;2 :> Fe+2 => Mn+2 > Zn+2 > Cd+2. It has been suggested that an incubation period following sludge/soil incorporation, allows organic matter to form or strengthen complexes with heavy metals which reduces metal availability for plant uptake.40 The forming or streng- thening of heavy metal-organic matter complexes with time may partially account for the decreased metal uptake with successive cropping after a one time addition of sludge.16 2) Soil physical properties It has been recognized for some time that substantial additions of organic matter to a soil influence the physical properties of the soil. Because sewage sludge composts con- tain a considerable percentage of organic matter, it should be expected that incorporation of compost into the soil should alter some of the physical properties. Compost additions have been found to lower the bulk density of mineral soils.z’ 20’ 43 Lower soil bulk densities brought about by compost additions may be attributable to the fact that compost material has a substantially lower bulk density than does a mineral soil. Simple dilution of the heavier mineral soil with the lighter compost should result in a lower overall soil bulk density. The increased aggregation that occurs when organic matter is added to a soil may also aid in reducing the bulk density of 22 CompoSt additions, while lowering soil bulk density, 43 a soil. may increase the compactability of a soil. Mays et al., I4 measuring the compressional resistance of a Sango silt loam, with a penetrometer, found that the compressional strength required to cause soil compaction decreased significantly when 327 mt/ha compost was incorporated into the soil. Compost, which has a water holding capacity of approxi- mately 5 times that of soil (weight basis), alters the moisture retention characteristics of the soils into which it is incor- 45 Adding compost to the soil shifts the moisture porated. retention curve of the soil to a higher water content at a given matric potential. The shift in the soil water retention curve can be attributed to increased sorption of water caused by the addition of organic matter present in the compost.31 Increases in the soil moisture content and moisture holding capacities of soils reported by several authors as a result of compost additions can be related directly to the shift in the moisture retention curve.1’ 20’ 26’ 43 Conflict exists concerning the influence compost incor- portation has on plant available water. Epstein et al.,26 have found that a compost application of 240 mt/ha made to a ‘silt loam soil, increased the amount of water held between - 0.33 and - 15 bars potential by 2.0 percent. Angle et al.,1 on the other hand, have reported that no increase occurs in the amount of available water when compost additions of up to 720 mt/ha are made to a sandy loam soil. Less drought suscepti- bility of corn has been reported when c0mpost additions to a 43 Sango silt loam soil have exceeded 36 mt/ha. This may be 15 due to the fact that more water is available for plant use or may just reflect the ability of the corn plant to develop a deeper more extensive root system in a compost-amended soil. The hydraulic properties of soils have been shown to be influenced by sewage sludge additions. Both Gupta et al.,31 22 and Epstein have reported increases in the saturated hydraulic conductivity values of soils amended with sewage sludge. Murray45 has reported thatzicompost application of 224 mt/ha increased the infiltration rate of a silt loam subsoil by 3 fold. The increased pore space that results from compost or sludge incorporation may account for the increased movement of soil water under saturated flow conditions. D. Effect of Compost on Turfgrass The use of commercial sod farms as landspreading sites for composted sewage sludge holds great promise if it can be demonstrated that compost applications are not detrimental to turfgrass sod production. The primary concern which would preclude the use of compost is the possible toxic effect of heavy metals on turfgrass growth. Angle et al.,2 found that no significant increase in the Fe, Mn, Cu, Pb, A1, C0, or Cr occurred in Kentucky bluegrass (Poa pratensis L.) or tall fescue (Festuca arundinacer) clippings when compost rates of up to 720 dry mt/ha were incorporated into a sandy loam soil. The only metal the authors found to increase in tissue con- centration with increasing compost levels was Zn. Mean foliar 16 Zn levels for both grasses were found to rise from 40 ug/g to 55 ug/g upon the addition of 720 dry mt/ha compost. The Zn increase, although statistically significant, was not great enough to adversely affect topgrowth of either grass. Metal loading of soils may affect the root growth of grasses. It has been shown that sludge type influences the rooting of bermudagrass cuttings. Burns,14 measuring total root length, found that cuttings grown in industrial sludge had only 22 percent the length of cuttings grown in residential sludge. Additionally, he found that the cuttings grown in the industrial sludge had only 80 percent of the number of root primordia compared to cuttings grown in the residential sludge. He attributed the differences in root length and root formation to the large differences in the metal content of the two sludges. Sod grown on industrial sludge has been shown to exhibit more environmental stress when transplated than sod grown on residential sludge.13 Successful utilization of activated sewage sludge for turfgrass establishment has been demonstrated for over 50 years.48 Increased rates of turfgrass growth together with improved turf quality have been reported with compost addi- 2 45, 58, 59 tions. ’ When compost was incorporated into a Galestown sandy loam soil, it was found to increase the speed of germination and rate of establishment of Kentucky blue: 59 grass. However, when compdst was used as a topdressing after seeding, it tended to reduce the germination of Kentucky blue- grass.59 Murray45 has emphasized the importance of having l7 irrigation available at the time of seeding to aid in the leaching of salts present in the compost if insufficient rain- fall should occur. In order to produce sod of high quality which reroots readily and does not tear upon handling, it is essential that the turfgrass have a vigorously growing root and rhizome system. Compost-amended soils have been shown to produce sod which reroots readiLywhen lain upon non-composted soils.4S Reroot- ing of sod produced on non composted soils has been found to improve when lain on soils amended with compost.4S Sod strength measurements have been shown to serve as a good indicator for evaluating the degree of development of roots and rhizomes in turf.S Periodic compost topdressing (which amounted to 44.8 dry mt/ha annually), have been found to result in sod strength measurements which are comparable to 59 This indicates that that of a standard fertilizer treatment. light frequent topdressings of compost may be able to partially or fully fulfill the fertilization requirements of turf for sod production. Topdressing applications of compost may not be desirable though due to the fact that wood chips present in the compost tend to interfere with the sod cutting operation.59 32 have reported that compost incorporation of Hornick, et al., 58 to 175 dry mt/ha (depending on the fertility level of a soil), will provide sufficient amounts ofall essential nu- trients, except K, for turfgrass growth, for a period of 5 to 6 months. MATERIALS AND METHODS A. Field Operations 1) Site location Cooperative research plots were established with 2 sod farms in southeast Michigan near Detroit. The Huron Sod Farm in Romulus, and the Waltz Green Acres sod farm in New Boston, served as plot site locations. Growers at both sod farm locations were responsible for seeding of the plot areas and for maintaining the normal cultural practices (i.e., mowing, fertilization, watering) associated with growth and development of the sod. Personnel from the Department of Crop and Soil Sciences at Michigan State University applied the treatments. The soils located at the two plot sites were an Oakville fine sand (0-2% slope, well drained) at the Huron Sod Farm and a Pewamo sandy clay loam (0-2% slope, poorly drained) at the Waltz Green Acres sod farm. Select physical and chemical properties of each soil are presented in Table l. 2) Compost The compost utilized in this investigation was produced by mixing Detroit dewatered sewage sludge cake (30% solids) with soft and hardwood "whole tree" wood chips in a 18 19 Table 1. Characterization of the soils at the two sod farm plot locations. Sod Farm Waltz Huron Green Acres soil type Pewamo sandy Oakville fine clay loam sand pH (1:1) 6.6 4.9 8 Sand 53.1 93.2 % Silt 20.4 4.0 % Clay 26.5 2.8 % Organic Matter 4.0 2.0 ppm P 80 280 ppm K 170 100 ppm Ca 4970 390 ppm Mg 810 25 Cation Exchange Capacity meq/100g 14.8 3.2 Soil Classification Typic Argiaquolls Typic Udipsamments fine, mixed, mesic mixed, mesic *Extractable in ammonium acetate pH 7.0. 20 volumetric ratio of 2.95 to 1 wood chips to sludge cakes). The "Beltsville Aerated Pile Method" of composting was used in making this compost, with the exception that due to time constraints, no 30 day "curing" period of the compost took 49 place. Analyses of compost samples taken at the time of application is presented in Table 2. 3) Plot design and treatment Each sod farm site consisted of 8 treatments, replicated 4 times in a randomized complete-block design. Treatments consisted of 4 rates of compost application and two depths of compost incorporation (Table 3). At the Huron Sod Farm (Huron) site individual plot size was 4.9 m by 6.1 m, while at Waltz Green Acres sod farm (Waltz) it was 6.1 m by 7.3 m. Prior to applying the various treatments at the Waltz site the plot area was plowed to a depth of 20 cm, disced and leveled. Due to the low percentage of clay present in the soil at the Huron site, preplant tillage of this soil prior to compost application was not necessary. Compost applications were made to the plots by utilizing a front- end loader and a large plywood box of known volume. The amount of compost necessary for each plot was determined on a volumetric basis (compost density, 1585 kg/m3) utilizing the plywood box. After the correct amount of compost material had been placed onto each plot it was raked evenly over the entire plot. Table 2. Analysis of the sewage sludge compost applied to the 21 two sod farms. -——————Sod Farm Huron Waltz Acceptable* pH 7.1 6.9 --- % Solids 73 73 --- % Nitrogen N.D. 0.95 --- ppm Cd 60 59 25 Cr 1180 1080 1000 Cu 540 540 1000 Pb 570 570 1000 Ni 480 480 200 Zn 1680 1670 2500 *Recommended limits of metal concentrations for sludges in Michigan -- L, W, Jacobs., Michigan State University. Cooperative Extension Service Bul. March 1981. File 32.63. +Analysis determined on 2 year old compost sample. 22 Table 3. Treatments applied to Huron and Waltz Green Acres sod farms August 21, and 22, 1979. Treatment Compost Applied Rototilling Depth Number mt/ha cm 1 0 10 2 0 10 3 0 20 4 84 10 5 168 10 6 84 20 7 168 20 8 252/336* 20 *Lower compost rate applied at Huron Sod Farm, higher compost rate applied at Waltz Green Acres sod farm. 23 Compost was incorporated into the soil by rototilling in 2 directions over the plots at the desired depth of incor- poration. The compost treatments were applied and incorpor- ated into the soil on August 21 and 22, 1979 at the Huron and Waltz sites, respectively. 4) Establishment Seeding of the plot areas to Kentucky bluegrass (Poa pratensis L.) at a rate of approximately 50 kg/ha was per~ formed by the sod growers during the last week of August in 1979. The Huron site seed blend consisted of 50% Baron, 25% Cheri and 25% Majestic while the Waltz site seed blend consisted of 25% Baron, 25% Nugget, 25% Touchdown and 25% Glade. Due to insufficient rainfall and lack of snow cover in the fall and winter of 1979-1980 it was necessary to reseed both locations in the spring of 1980. Rainfall amounts recorded at Detroit Metro airport for the months of September and October were 2.4 and 3.1 cm respectively. Utilizing the same seed as in the previous fall, the Huron site was reseeded on May 10, the Waltz site on May 27. 5) Visual observations Commencing in April of 1980, monthly visual observations of percent plot cover were taken at the Huron site. Because of the slower seed germination on the finer-textured soil, visual observations of the percent plot cover at the Waltz site were not begun until July. Percent plot cover evalu- ations were continued at each site until no significant difference among the various treatments could be detected. Turf color and visual quality ratings were initiated when sufficient turf plot cover allowed for meaningful visual evaluation of these parameters. At the Huron site, color and quality evaluations commenced in June and July, respec- tively, while at the Waltz site, quality and color evalua- tions began in September and October, respectively. Color and quality evaluations at both sites were continued until the end of the study in October of 1982. 6) Tissue and soil collection Clippings were collected at the Huron site for tissue analysis on July 31, 1980 and September 6, 1981. At the Waltz site, clippings were collected on July 29, 1981 only. Clippings were not collected from the Waltz plots in the summer of 1980 because of insufficient turf cover in the plots. Clippings from each plot were collected by making one pass down the center of each plot with a 53 cm wide rotary mower set at a height of 4.4 cm. Fresh clippings collected in the catcher bag of the mower were placed in paper sacks and transported to the laboratory. The samples were forced air dried at 55 C for 48 hours, ground in a stainless steel Wiley mill to pass through a 40 mesh screen, then stored in glass jars until analysis. Prior to grind- ' ing the 1981 samples, dry clipping weights of the plots at each ~site-were recorded to measure the long term effect of’ compost incorporation on turf growth rates. 25 Soil samples, taken to a depth of 10 cm, were collected July 7, 1980 and August 21, 1981 from the Waltz plots and July 18, 1980 and September 19, 1981 from the Huron plots. The soil samples were forced air dried at 25 C for 24 hours. The dried samples were ground in a stainless steel mill to pass through a 2 mm screen and were stored until analysis. 7) Sod strength Sod strength measurements as developed by Rieke52 were determined for both sod farm plot locations when visual observations suggested that a mature sod stand existed. Sod strength measurements were taken on August 19, and September 21, of 1981 at the Waltz and Huron site locations, respectively. Mean plot sod strength values were determined by measuring the sod strengths on 3 or more, 0.4 meter by 0.9 meter sod strips. At the Waltz site sod was cut to a depth of 0.6 cm while at the Huron site the depth of cut was 1.2 cm. 8) Physical measurements At each plot location soil cores were collected from beneath the sod strips that were cut for sod strength measurements. Soil cores were removed from the Waltz plots on August 22, 1981 and from the Huron plots on September 25, 1981. The soil cores were removed in aluminum cylinders, 7.6 cm in length and diameter, utilizing a double-cycliner 26 hammer-driven core sampler.8 The cores were collected from those plots which had been rototilled to a depth of 20 cm at the time of compost incorporation (treatments 3, 6, 7 and 8 only). At the Waltz site, 10 cores were removed from each plot at a depth of 0.6 to 8.2 cm below the soil surface. At the Huron site, 6 cores were extracted from a depth of 1.2 to 8.8 cm. All six cores from each Huron plot and 6 of the 10 cores from each Waltz plot were utilized to determine soil bulk density, saturated hydraulic conductivity, and soil moisture retention characteristics. In addition these cores were utilized to determine the volumetric percentage of large wood chips present in the soil after two years. The remaining 4 cores collected from the Waltz plots were uti- lized in a compaction study explained in the laboratory analyses section of this chapter. The effect of compost on cumulative infiltration of water into the soil under field conditions was determined at the Waltz and Huron plot locations in mid August of 1981. Three double-ring, cylinder-type infiltrometers were driven into each plot and a constant head of 2.5 cm water was maintained over the soil inside the inner ring (diameter 15 cm) of each infiltrometer. Prior to and during the time water was maintained at a constant head within the inner ring, water was ponded between the inner and outer ring. The amount of water that infiltrated within the inner ring 27 was measured every 10 minutes for a period of 1 hour at the Huron site and every 20 minutes for a period of 3 hours at the Waltz site. Results were expressed as the total amount of water infiltrated into soil over a l or 3 hour time period, respectively. B. Greenhouse Studies 1) Seed germination The seed germination study was initiated to determine the effect various rates of compost incorporation had on turfgrass seed germination when subject to two different irrigation levels. A 4 X 2 factorial experiment replicated 4 times in a randomized complete block design was utilized for both soils in this study. The 2 soils used in this study were collected from the 2 field sites described pre- viously. Soil tests revealed that both soils were low in K and that the Oakville soil was low in Mg. Compost treatments consisted of mixing air-dry compost with each soil in volumetric proportions of 0, 25, 50, and 75 percent compost. Prior to mixing, both soils were screened through a 2 mm sieve. The soil-compost mixtures were placed into 400 ml waxed cottage cheese containers and were saturated for 24 hours. After allowing the free water to drain, "Hydro-wet" wetting agent was applied as a soil drench to all treatments at a rate of 50.8 l/ha. The treat- mentsiwere allowed to air dry for several days and were then 28 seeded to Manhattan perennial ryegrass (Lolium perenne L.). Approximately 175 seeds (0.524 g) were placed into each con- tainer and covered with 0.5 cm soil. The amount of water added to each container was measured using a graduated cylinder and transferred to a beaker for application to the soil. The first irrigation for all treat- ments consisted of 100 ml of water together with 50 ml of a fertilizer solution. With the exception of the first irrigation, all high irrigation treatments received 100 m1 of water twice weekly, while the low irrigation treatments received 25 m1 of water twice weekly. The Oakville soil received a fertilizer solution containing KCl (3.2 g/l) and MgSO4 (0.75 g/l), while the Pewamo soil received a ferti- lizer solution containing KCl (1.6 g/l) only. Five weeks after the first irrigation all perennial ryegrass seedlings were harvested and counted. 2) Turf growth and nitrogen uptake. The influence of compost of nitrogen uptake and turf- grass growth was evaluated in this study. A 5 X 3 factorial experiment, replicated 4 times in a randomized complete block design was utilized for the two soil types. Treatments con- sisted of 5 compost rates (0, 90, 180, 270, and 540 mt/ha) and 3 nitrogen levels (0, 293 and 586 kg n/ha/month). The respective soil-compost treatments were made up by mixing ‘256, 512, 768 or 1536 g of air-dry compost with 3~2» 3-°" 29 2.4 or 1.2 kg of air-dry-Pewamo soil, or 3.52, 3.24, 2.96 or 1.92 kg of air-dry Oakville soil. The various mixtures were placed into 2.5 1, 16.5 cm deep plastic pots. Four nail size holes were drilled through the bottom of the pots to allow for drainage. The pots were placed in water and the soil mixtures were allowed to satu- rate through capillary rise for 24 hours. The day the pots were saturated was considered day l of the study. After allowing the treatments to drain for 2 days (day 3 of study) each pot received 150 ml of the fertilizer solution described in the seed germination study. In addi- tion monthly applications of the nitrogen treatments began at day 3 of the study. Reagent grade ammonium nitrate dis- solved in distilled water served as the nitrogen source for this study. An incubation period of 8 weeks took place before the pots were seeded (0.524 g/pot) to Manhattan per- ennial ryegrass. Watering of the pots was performed as needed for the duration of the study. Beginning at 12 weeks into the study the turf was clipped at 4.0 cm every 14 days (i 1 day). At alternate cuttings, the clippings from each pot were collected, air dried at 55 C for 48 hours and weighed. Clippings col- lected from select treatments (0, 180 and 540 mt/ha compost, allnitrogen levels) were analyzed for total micro Kjeldahl 10 N at 14 and 34 weeks. Selected treatments from the Pewamo soil were analyzed formicro Kjeldahl N at 18 weeks as well. The study was terminated after 38 weeks. 30 C. Laboratory Analyses 1) Soil and tissue samples Soil and tissue samples collected from the field were analyzed for P, K, Mg, Ca, Fe, Zn, Mn, Cu, Ni, Pb, Cr, and Cd. Tissue samples of 1.0 g were dry ashed at 500 C for 10 hours, then dissolved in 5 m1 of 6 N nitric acid for 1 hour. Samples were brought up to a volume of 10 ml with 1000 ppm LiCl solution. A 0.2 m1 aliquot of the sample solution was transferred to 9.8 ml of 1000 ppm LiCl solution for analysis of P, K, Mg and Ca. The original 10 ml sample solution was used for determining the tissue concentration of Fe, Zn, Mn, Cu, Pb, Cr, Ni, and Cd. All tissue samples were run on a Spectrametrics Incorporated, SMI 3, multielement Plasma Emission Spectrometer corrected for background. Total N for field and greenhouse tissue samples was determined by the semi-micro Kjeldahl method.10 The soil extractable metals Fe, Mn, Cu, Pb, Ni, Cr, Zn, and Cd were determined by placing a 5.0 g sample of soil in an erlenmyer flask, adding 50 m1 of 0.1 N HCl and shak- ing for 1 hour. Samples were filtered through qualitative Whatman #1 filter paper and were analyzed on the Plasma Emission Spectrometer. Soil P, K, Mg, Ca and pH were deter- mined by the Soil Testing Laboratory at Michigan State University. .Relative differences in-soil organic matter were determined by dry ashing soil samples (9 to 10 g) in a muffle furnace for 16 hours at 450 C.” 31 2) Soil cores Soil cores were placed into a water bath and allowed to saturate for 48 hours by capillary rise. The cores, once fully saturated were weighed, followed by determination of saturated hydraulic conductivity. Saturated hydraulic con- ductivity of the soil cores was determined by the constant 39 Soil water characteristic curves for each head method. treatment were obtained by placing the soil cores on a ten- sion table at 30 cm tension for 48 hours, then subjecting the cores to increasing pressure potentials (0.1, 0.33, and 1.0 bar) on ceramic plates, at two day intervals. After exposing the cores to a pressure potential of 1 bar, the cores were oven dried and the bulk density of the soil was determined. Two of the 6 cores from each plot were selected at random to be broken up and thoroughly mixed together for the 15 bar moisture determination. Two 10 cm diameter samples were run at the 15 bar pressure potential for each composite plot sample. The volumetric percentage of wood chips present in the soil of Treatments 3, 6, 7 and 8 was determined by dividing the volume of wood chips present in each core by the volume of the core. Four cores from each plot were used for this determination. Each core was wet screened through a 2 mm sieve, and the wood chips collected. The volume of wood chips in each core was determined by measuring the amount of water displaced in'a graduated cylinder when the wood ' 32 chips were submerged under water. Air bubble entrapment, which occurred during submersion of the wood chips, may have added as much as 0.5% total volume to the reported mean of the highest compost treatment. No attempt was made to sub- tract the amount of volume displaced by the presence of the entrapped air bubbles. The compactability of the compost-amended Pewamo soil was determined by a confined compression test. An Instron Universal Testing Machine, Model TM, was utilized for this study. For the purpose of this experiment, the Instron machine was used to determine the force necessary to main- tain a constant rate of compression on a soil core. Four soil cores from each of the plots of Treatments 3, 6, 7 and 8 were utilized for this study. The cores were saturated, then equilibrated at 40 cm tension. A 7.4 cm piston was assembled to the Instron machine and was set at a velocity of 12.7 mm/min to compress the soil core. The force required to cause piston compression of the soil was monitored on a load cell up to 4.00 bars and was plotted against the distance of compression of the piston. After being compressed, the cores were oven dried for bulk density determinations. D. Statistical Analyses Treatment mean comparisons within each study of this investigation were examined by analysis of variance of each 33 data set. For factorial experiments, if the F test for treatments was significant at the 5% level, the least sig— nificant difference was examined at the 5% level. For all other experiments, if the F test for treatments was signifi- cant, treatment means were subjected to mean separation by Duncan's New Multiple Range Test. In order to simplify data presentation and to eliminate redundant information. Treatment 2 at both sites was omitted from all tables. In all cases, Treatment 2 means were not significantly different from Treatment 1 means. This would be expected in view of the fact that Treatments 1 and 2 were identical. RESULTS AND DISCUSSION A. Field Observations 1) Establishment Visual observations of the percent turf cover on the Oakville (Table 4) and Pewamo (Table 5) soils revealed that incorporation of compost inhibited seedling emergence and sod establishment of Kentucky bluegrass. However, with time the inhibitory effect of the compost diminished. The inhibitory effect of the compost appeared to be more pro- nounced on the Pewamo soil than on the Oakville soil. Initially the inhibitory effect of compost on sod formation was minimized on treatments where the compost had been incorporated to a depth of 20 cm. At the time of the first evaluation on both soils, turf cover was significantly higher with 20 cm depth of incorporation when compared with the 10 cm depth of incorporation for the 168 mt/ha compost rate. On the Pewamo soil, significantly higher turf plot cover was observed with the 20 cm depth of incorporation when compared with the 10 cm depth of incorporation for the 84 mt/ha compost rate as well. By the second evaluation, depth of incorporation had no effect on percent turf cover at either site. The third evaluation at each site revealed that no significant difference in turf cover existed among all treatments. 34 .wcsouw omen op Hence o .uo>oo.mmmwmmwsu esswxma ow fiasco ooH spa: onom ooH ou o m :o owes mopmefiumo Hmzmfi> one mmqmumu po>ou usoopome .umoh omcmm oamfiuazz 362 m.:mu::Q zn Ho>oH wm one an ucowowwflw xagcmuflmficmflm Ho: ohm :ESHoo m :ficafiz wouuoa 65mm on» mcw>ms memos unoEumoue+ a m.am a m.mm a o.ma e6 m.Ha me w.mm om NmN a o.mm m m.Nw a m.aa eon m.~a e6 o.me om mom a n.8m a m.~m m o.ow am m.ma on o.om om em m.am m o.ma m o.oa e m.ao o m.mm OH ”CH m.mm m m.ma a m.na on m.ma non m.ae OH 4m m.~m a m.aa m o.om m m.Hm a o.oo om o m o.mm a m.aa a o.ma one m.oa +nm m.em OH o epo>oo uon w Eu ,m:\ue om\mN\m om\em\a om\m~\o om\vm\m om\m~\¢ :ofiumaoanoueu “menace acosumouh .Hfiom oHHfl>xmo 0:9 :0 com mmmwmozan xxospcox mo unoEmoHo>ow mo open may no umomaou mo uoommm. .v oflnme .Oaaowm cums on Hence O .ho>oo mmmhmmHSH EastmE ou Hence OOH :HHZ onom OOH OH O m :o owes moumEHumo HemmH> one mwaHump uo>oo acoonome .wmoh owned onHuHsz zoz m.:mocsa zn Ho>oH Hm can we “cohommHO xHucm0HchmHm Ho: ohm cezHoo m :ngHz pouuoH osmm ecu wcH>mn msmos uzosumouh+ 36 m m.~O m O.NO o O.Nm on 0.0H ON cmm m m.HO m 0.00 on m.~O a 0.0~ ON OOH m O.mO m O.mO m m.mn m m.OO Om em 8 m.nO m O.mO on m.HO o m.OH OH OOH m m.HO m O.mm am m.Hn on m.ON OH am. e 0.00 m 0.00 m 0.0u m m.Om ON O _ m O.mO m m.HO m m.~m +8 O.mm OH O wuo>oo uon H Eu m:\u5 OO\mN\OH OO\m~\O OO\ON\O OO\ON\A :oHumuoauooeH «monsou “coaumoue .HHom osmzom . one :0 wow mmeuwoan xxozucox mo pcoenoHo>oO mo oump map so umomEoo mo uuomwm .m oHnt 37 Observation November 27, 1979 revealed that water "beaded up" upon application to the surface of the compost- amended soils. This indicated that a hydrophobic soil con- dition had developed on the plots amended with compost. Lack of sufficient rainfall in the month of September, following treatment application, allowed the compost-amended soils to dry out. The dry conditions promoted the develop- ment of the hydrophobic condition. The hydrophobic soil condition was likely responsible for the greater delay in bluegrass seed emergence observed on the compost-amended plots. Hydrophobic soil conditions resulting from oily sludge additions have been implicated in the inhibition of perennial ryegrass (Lolium multiflorum Lem) seedling emer- gence.11 Continued surface hydrophobic conditions were not observed on either soil the following spring. 2) Turf color and quality Turf color ratings were made on a l to 9 scale with 1 equal to a completely brown, dormant turf; 3, a yellow colored turf; 6, an acceptable green turf; and 9, a very dry green turf. Turfgrass quality ratings were based on turf density, vigor color, uniformity and verdure. The aspect of color was deemphasized in an attempt to avoid repeating information already given in the color ratings. Turf plots receiving a quality rating of 6 or above were considered to be acceptable for sod harvesting and sale. - .151." c,- l—l:;¥ carp-r, I. . Color ratings at the Huron site during the 1980 growing season (Table 6) revealed that the presence of compost in the Oakville soil resulted in a reduction in green color of the turf. Yellowing of the turf in the compost-treated plots was greatest in the months of August and September and was least noticeable in the month of June. From August until color evaluations ceased in October (1980). All com- post treatments had color ratings which were unacceptable (below 6). In contrast, the two check treatments had acceptable color throughout this period. With the exception of the month of June, both check treatments were judged to have significantly darker green color than all compost treatments throughout the entire 1980 growing season. Color ratings taken in early spring (1981) at the Huron site (Table 7, Oakville soil) revealed that turf grown in the compost-treated plots had earlier spring "green up" than turf grown in check plots. All compost treatments with the exception of the 84 mt/ha-lO cm Treatment had signifi- cantly darker green turf than the two check treatments in April. With the color evaluation 32 days later, the trend in turf color reversed. Throughout the summer months of 1981 turf color ratings for all treatments were not significantly different from one another at the Huron site. Color ratings in October of 1981 suggested that the two check treatments » had significantly better fall color than did the compost treatments.~ GOSH 02d MCHAZHJ H434“ miner—HHDZHS >4-J..u:.vv~ .3 -HCHCL 1:9 I: «SCIEII k! i u I! 51" l.‘ n. 4‘ l‘ I. II In... .oHnmnHmpum HoHoo .8on H.236 OBEmeE on» msHoO O Ocm .mwzu onHoz xHouo>om m m .mp3» «cashew czonn xHouoHQEoo OcHon H .uoHou oHnmumouum EschHE onp OaHoO O :qu onom O ou H m :o owns moumEHumo HmsmH> ohm mwcHumu HoHou« .umoe owned oHaHuHaz 3oz m.:mo::o An Ho>oH Om onu um HcopoHMHO prcmonHamHm Ho: ope :ESHoo m :chHz hopuoH osmm can O:H>m: memos unoEumoue+ a O.¢ o m.v u m.O n m.O on m.m ON NmN n m.v on O.m o 0.0 n m.m on m.m ON OOH 9 n O.m O O.m on O.m n 0.0 on O.m ON _ «O .3 a O.v on m.m on O.m n 0.0 u O.m OH . OOH n O.v on m.m O O.m n 0.0 pm m.O OH OO O 0.0 m m.n m O.n m 0.0 on 0.0 ON O m m.O m 0.0 m 0.0 m m.O +m m.n OH _ O ewcHHmH HoHoo Eu m:\us. OO\mN\OH OO\mN\m OO\mN\O OO\4N\N OO\mN\O aoHumwomaoo:H_ “menace unoEumonh .HHom oHHH>xmo one :o condom OcHzouO OOOH on» Ochaw Oom mmmumosHO xxosueom mo HoHoo ecu :o umomsou mo uoommm ..O oHOmH .oHOmchuum HoHoo :ooHO HHOO ESEHXOE ecu OchO O mam Okay onHo» zHoHo>om m m .whzu pamEHoO conO xHouonEoo Ochn H .HoHoo oHnmumooum ESEHOHE on» OcHon O :qu onom O on H O so OOOE moumEHumm HmsmH> mum mwchOH HoHoUO .umms omcmm oHOHquz 3oz m.:mucsa kn Ho>oH Om onu um uqmpmmmHO prcmoHMHcmHm Ho: ohm :ESHoo m :chHz HmuuoH 05mm ozu O:H>m: memos ecosummhe+ O O.O O N.N O N.O O O.O O N.O O O.m ON NON o m.m O N.N O O.O O N.O OO O.O O O.O ON OOH OO N.m O O.N O N.O O N.O OO N.O O m.m ON OO O O.m O O.N O O.O O N.O OO O.m OO 0.0 OH OOH u O.m O O.N O N.m O N.O OO O.O 8O N.m OH .. OO O O.O O N.N O O.O O O.N O O.O OO N.N ON O O N.O O N.N O N.m O O.N O O.O +O O.H OH ‘ O OO:HHOH HoHoo so _ m:\us HO\O\OH HO\H\O HO\ON\N HO\OH\O HO\OH\O HO\OH\O :OHOOOOOOOOOH «Ooaeou acoEumouh .HHom oHHH>xOo on» :o :omwmm OcHZoHO HOOH may OcHHSO wow mmmpmoan OOUSHGox mo HoHoo on» :o pmomsoo mo uuommm. .O oHOme 41 Color ratings taken at the Waltz site (Pewamo soil) in April of 1981 (Table 8) agreed with the Huron April color ratings in that turf color was significantly darker green in the compost amended plots. With the exception of the 84 mt/ha-ZO cm Treatment, all compost treatments were judged significantly darker green in color in early spring than the two check treatments. Increased availability of macronu- trients, resulting from the addition of the compost (see tissue and soil samples section of this chapter), may be responsible for the earlier spring "green up" observed on the compost-treated plots. Throughout the 1981 growing season the medium and high compost treatments (168 mt/ha-lO cm, 168 mt/ha-ZO and 336 mt/ha-ZO cm) at Waltz (Pewamo soil) had significantly higher color ratings than the non compost treatments. In the fall striking differences in color existed between the various treatments at Waltz. All compost treatments were judged to have significantly darker green color than the check treat- ments. Acceptable turf color was present only on the two highest compost treatments (336 mt/ha 20 cm, 168 mt/ha 10 cm) in October at the Waltz site. Quality ratings taken in 1980 at Huron (Oakville soil) revealed that no significant differences existed among the various treatments. In 1981 (Table 9), with the exception of the months of July and August, the highest compost treat- ment at the Huron site (252 mt/ha-ZO 'cm) was judged 42 .oHOmaHmuum HoHoo :mmHO HHOO ESEHXOE 0:9.OGH0O O Ocm .mHSH onHox AHon>om m m .wHSH ucmehow czoun xHouonEoo OzHon H .HoHoo oHOOumooom EschHe may OcHoO O zqu onom O op H O :o owns moumEHumo HmzmH> mum mwcHuOH HoHou . O .umoh omcmm onHuHsz 302 m.:mo::n >2 Ho>oH Om osu um pcwpomeO xHucmonHcmHm Ho: ohm cesHou m :HOHHS HouuoH oemm may O:H>m: mauve acoaummuh+ O O.O O O.N O O.O O O.O O O.O ON OOO O O.O O O.O OO N.O OOO O.O O N.O ON OOH u N.O O O.O OO O.O u O.O OO O.O ON OO O O.O O O.O OO 0.0 OO 0.0 O O.O OH OOH o 0.0 O 0.0 UO O.O OO O.O O O.O OH . OO O O.O u O.O O N.O O O.O O O.O ON _ O O N.O 6O N.O OO N.O O 0.0 +OO N.O OH O OmsHuOH HoHou Eu . m:\HE HO\O\OH HO\ON\N HO\NH\O HO\OH\O HONOHNO OOHOOOOOOOOOH OOOOOOO unoEumouh . .HHom osmzom ecu :o commom OcHonO HOOH on» OcHHSO wow mmmumman xxuaucox mo HoHoo on» :o “momsoo mo uomwmm .O oHan 43 .HHHHOSO mmmpwmuza oHOmummoom op Hmzco O Ocm Ocsoum onO OH Hmscm H .HOHHmsc mmmHOwHSH EsemeE op Hmsco O OOH: mHmom O op H m :o owns mmuOEHumo Hm3mH> mum mmcHumu quHm30¢ .umoe omcmm oHOHquz zoz m.:mo::a An Ho>oH Om onu um HcmuomeO HHucmonHcmHm Ho: OHO cesHoo m :HOHHS HouuoH oamm may O:H>m: mcmos unoEHOoHH+ O O.O O O.O O O.O O H.O O O.O O H.O ON . NON OO H.O O N.N O O.O OO O.O OO O.O OO O.O ON OOH OO N.O OO N.O OO H.O OO O.O OO 0.0 OO N.O ON OO OOO 0.0 OO 0.0 OO N.O OO O.O UO 0.0 UO 0.0 OH 5 OOH OOO 0.0 OO N.O OO 0.0 OO H.O UOO O.O 0O 0.0 OH , OO OU 0.0 OO O.O OO O.O 6O O.O OO 0.0 OO N.O ON .O O H.O O N.O O H.O u O.O u O.O +8 N.N OH O «OcHumH HHHHOSWI. Eu . m:\us HO\O\OH HO\H\O HO\ON\N HO\NH\O HO\OH\O HO\OH\O OOHOOOOOOOOOH Hmoasou “coaumone . .HHom oHHH>HOo on» :o commom OcHonO HOOH ms» Othnc Oom mmmHOosHO Hmonucox mo quHmzc one :o umomEoo mo auommm. .O oHan s 44 significantly better in turf quality than the checks. Low quality ratings in July were due to lack of rainfall for a period of 3 weeks prior to the rating. The 252 mt/ha- 20 cm and 168 mt/ha 20-cm treatments were found to have significantly better turf quality under moisture stress conditions when compared to the 0 mt/ha-lO cm Treatment but not the 0 mt/ha 20-cm Treatment. The lower drought susceptibility of the compost-amended plots can be attri- buted to the increased available water holding capacity of the plots (see soil physical properties section of this chapter). Compost treatments at the Waltz site (Pewamo soil) began to exhibit significantly higher turf quality ratings in June of 1981 when the sod began to knit together (Table 10). The highest compost treatment (336 mt/ha-20 cm) re- sulted in higher quality turf than both check treatments from June of 1981 until the end of the study. In the final quality rating (October 1981) at the Waltz site, all compost treatments were judged to have significantly higher quality turf than the non-compost treatments. While all treatment effects were not found to be significantly different at the Huron site in 1980, clear differences in certain aspects which make up the composite 'quality rating were apparent. Compost-treated plots appeared to produce more topgrowth than thecheck plots. The highest compost treatments (252 mt/ha-ZO cm, 168 mt/ha-lO cm) ap- peared to have excessively lush topgrowth during the months 45 .HHHHOSO mmOHOmusu OHOOuOouoO ou HOsco O OOO Ocsopm OHOO ou HOzcm H .quHOzc mmOuOMOSH ESEHKOE op HOOOO O OHH3 OHOom O on H O :o QOOE mmquHpmo HOsmH> OHO OOOHHOO quHOnoO HOOHOOOHO HHOOOUHOHOOHO Ho: OHO :ESHou O OHOOH3 HouuoH oEOm mOp OGH>OO .umoh OOOOO OHmHuHsz 3oz O.OOuczn HO Ho>oH Om OOH HO choE unoEuOoye+ O 0.0 O 0.0 O 0.0 H.O O N.O ON Omm OO 0.0 OO 0.0 OO N.O N.O O N.O ON OOH o 0.0 oO H.O OO H.O 0.0 O 0.0 ON OO O 0.0 O 0.0 OO N.O N.O O 0.0 OH OOH u 0.0 oO H.O OO N.O 0.0 O 0.0 OH OO O N.O O 0.0 O 0.0 N.O O 0.0 ON O O N.O OU 0.0 O 0.0 0.0 +O N.O OH O «OOHHOO OHHHO3O1 so OO\uE HO\O\OH HO\ON\O HO\OH\O HO\OH\O HO\OH\O :oHuOHoOHoozH umomsoo HmoEuOope .HHom oEO3OO OOu :o :omOom OOH30HO HOOH OOH OOHHSO Oom mmOHOozHO HOUJHOOO mo HHHHODO OOH :o umoasoo mo Hoowwm..OH OHOOH 46 of July and August. Topgrowth did not appear excessive at any compost rate, at either site in 1981. Excessive Kentucky bluegrass growth has been observed on a Sassafras sandy loam soil amended with 360 and 720 mt/ha compost.1 Although topgrowth was clearly greater on the high compost-treatment plots, uneven growth was observed within these plots. Check plots, while exhibiting less topgrowth, were much more uniform in growth habit throughout the plot. Knitting of the grass to form sod appeared to occur more readily in the non compost treated plots. The bulkiness and heterogeneous consistency of compost, caused by the pres- ence of large Wood chips (> 1.0 cm), was most likely responsible for the lack of uniform turf growth. The presence of large chips made uniform soil incorporation of all compost size fractions difficult. While lack of uniform turf growth within the compost- amended plots was a negative aspect in the quality rating evaluations in 1980; once the plots began to fill in the uneven growth observed in these plots began to diminish. As uniformity in turfgrass growth and density began to appear within the compost-treated plots (1981), higher turf quality ratings were observed on these plots. “B. Tissue and Soil Samples 1) Soil macronutrients Tables 11 and 12 present the pH and macronutrient test analysis results from the Oakville and Pewamo soils, 47 OOH OOoEO msomHHOQEou HOOeOHOoHOOz .OONHHOOO Ho: OHo3 mHOON 03H .HOOH OOOOO OHOHHHsz 3O2 O.OOOOOQ NO Ho>OH OO OOH HO HOOHOmmHO NHHOOOHOHOOHO Ho: OHO :ESHou O :HOHH3 HOHHOH OEOm OOH OOH>OO OOOOE HOOeHOOHH+ O HOH OO OOOH O ONH O OOO O N.N ON NON O OOH OO ONOH O OHH O ONO O O.N ON OOH O ONH o OOOH OO OOH O OOO O 0.0 ON OO O OON O ONOH O ONH O OOO O O.N OH OOH O NOH UO OOOH O OHH O ONO O 0.0 OH OO O OOH O OOO UO OO O ONO O 0.0 ON O O OO O OOO o OO O ONO +O 0.0 OH O OOHOEOO HOOH O OOH O OOOH O OOH O OOO O N.O ON NON O OHH OO OOOH OO ONH O ONO O 0.0 ON OOH O ONH o OOHH UO OOH O ONO O 0.0 ON OO O OOH OO OOOH O OOH O ONO O N.O OH OOH O OHH O OOOH OO ONH O ONO OO 0.0 OH OO O OO O OOO Oo OOH O.ONO o 0.0 ON O O OO O OOO O OHH O ONO +o N.O OH O Emu Eu OO\HE OOHQEOO OOOH O2 O0 M O In :oHHOHomHousm Hmomaoo HOOEHOOHH .HOOH .OH OOOEOHOOO. .OOOH .HN HHOO OOHQEOO OOO ONOH .HN Hmswz< :o OHOOEHOOHH HmomEoo maoHHO> OHH3 OOOOOEO HHom OOOm OOHm OHHH>OOO :O mo mHO>OH 2m OOO HOOEOHOOHOOE OHOOHOOHme .HH OHOOH 48 o3H OOH OOoEO OOOOHHOOEou HOOEOHOoHOOz .OONOHOOO Ho: OHO3 OHOOO .HOOO OOOOO OHOHHHsz 3O2 O.OOOOOO OO Ho>OH OO OOH HO HOOHOOOHO OHHOOOHOHOOHO Ho: OHO :EOHoo O :HOHH3 HOHHOH OEOO OOH OOH>OO OOOOE HOOEHOOHH+ O OON O OHHO O OOO O OOO O 0.0 ON OOO O ONN OO ONHO O OHO oO OON O 0.0 ON OOH O OON Oo OHOO O ONN Oo ONN O 0.0 ON OO O OHO OO OOOO OO ONO OO OHO O 0.0 OH OOH O OON oO OONO O OOO OO OON OO N.O OH OO O OHO O OHOO O OON O OOH O 0.0 ON O O OON O OOOO O OON O OOH +0 0.0 OH O OOHQEOO HOOH . O OOO O OOOO O OOO O OHO O O.N ON .OOO O OON OOO OOOO UO OOO O OON O O.N ON OOH O OHN UO ONNO o OOO OO OON O 0.0 ON OO O OON OO OOHO O OHO O OHO O 0.0 OH OOH O OON UOO OOOO o OHO O OON O 0.0 OH OO O OOO o ONOO o ONN O OOH O 0.0 ON O O ONN u OOOO o OON O OOH +O 0.0 OH O Ema Eu OO\HE OOHQEOO OOOH O2 OD x O mm OOHHOHoOHOOOH Hmomsou HOOEHOOHH .HOOH .HN OOOOO< .OOOH .N NHOO OOHQEOO OOO ONOH .NN Hmams< :o OHOOEHOOHH HmomEoo msoHHO> OHH3 OOOOOEO HHom EOoH HOHO NOOOO oEO3OO O mo OHO>OH mm OOO HOOEOHOoHUOE OHOOHOOHme .NH OHOOH 49 respectively. With both soil types, incorporation of Detroit sewage sludge compost raised soil pH. The liming effect of the compost was more evident on the Oakville soil due to the lower initial pH and buffering capacity (CEC) of this soil. In view of the fact that the pH of the compost was in the range of 6.9 to 7.1, the liming effect of the compost on the two soils was not unexpected. Soil extractable K and Ca levels were significantly increased both years following compost incorportation of 168 mt/ha or more of the compost on both soils. In 1980 the Oakville test results revealed that the 252 mt/ha-ZO cm, 168 mt/ha-20 cm, and the 168 mt/ha-lO cm treatments raised extractable Ca levels up to 3 times over the Ca levels found in the check plots. Because of higher native Ca levels in the Pewamo soil, Ca increases of this soil were not as dramatic. Soil extractable Mg levels were raised significantly by compost incorporation on the Oakville soil, but no signifi- cant differences were found among Mg soil tests on the Pewamo soil. All compost treatments except the 84 mt/ha-ZO cm Treatment had significantly higher extractable P levels than check treatments in 1980 and 1981 on the Pewamo soil. There was no significant difference in extractable P among ~the treatments of the Oakville soil in either 1980 or 1981 although the trend in extractable P treatment means of the Oakville soil did suggest that mineralization of P in the compost had occurred. Taylor et al., reported extractable 50 P did not increase linearly with compost addition and that on some soils compost P tends to undergo immobilization after a net mineralization.S6 2) Tissue macronutrients Macronutrient analyses of the Huron (Oakville soil) 1980 clippings (Table 13) revealed that although some signif- icant differences in P, Ca and Mg concentrations occurred these differences were small and not consistent with treat- ments. Variability in N and K levels was too great to attach significance to these treatment means. By 1981 there was no significant difference among the macronutrient con- centrations in the clippings at the Huron site so the data were excluded. Nitrogen, P and K levels in the clippings were found to increase with compost addition at the Waltz site (Pewamo soil) in 1981 (Table 14). The higher N clipping content from compost treatments was most likely responsible for the higher color ratings observed at Waltz in 1981 (Table 8). All compost treatments had significantly higher K levels than the checks. Treatments receiving 168 mt/ha or more of compost were found to have significantly higher N and P levels than the checks. Calcium levels in the clippings were found to be suppressed with increasing compost rates. 53 Satari has reported suppression of Kentucky bluegrass Ca levels with K fertilization. Additional K availability 51 .HmOe OOOOO OHQHHHOZ 3O2 O.OOOOOQ OO HO>OH OO OOH HO HOOHOmmHO NHHOOOHMOOHO Ho: OHO GEOHOO O :HOHH3 HOHHOH OEOO OOH OOH>OO OOOOE HOOEHOOHH+ O NH. OOOO OO. O OO.N O OO. O ON.O ON .5 NON O OH. OO HO. O NO.N oOO Om. O ON.O ON . OOH O ON. OOO OO. O NO.N OO OO. O O0.0 ON , OO O OH. O OO. O ON.N O OO. O O0.0 OH OOH O OH. UOO OO. O NN.N UOO Om. O O0.0 OH OO O NH. O HO. O OO.N O OO. O O0.0 ON O O NH. Oo NO. O OO.N oO Om. +O O0.0 OH O .H3 OHO O Eu OO\HE O2 O0 O O 2 OOHHOHOQHOOOH HOOOEOO HOOEHOOHH .HHom OHHH>OOO OOH SOHO OOOH .HO HHOO OOHmO>HOO OOOHOOHHO OOOHOOOHO OOOOHOOO mo mcoHHOHHcoocou HOOEOHOOHOOE .OH OHOOH 52 .HOOH OOOOO OHOHHHOZ 3O2 O.OOOOOO NO HO>OH Om OOH HO HOOOOOOHO NHHOOOHMHOOHO Ho: OOO OesHou O OHOHHz OOHHOH OEOm OOH OOH>OO OOOOE.H:OEHOOHH+ O NH. O me. O HO.N O NO. O HO.N ON Omm O NH. OO OO. OO ON.H UO HO. O OO.N ON OOH O NH. UO NO. OU mO.H OO Om. UO OO.N ON OO O NH. o mO. OO HO.H OO mm. O HN.N OH OOH O OH. OO OO. O Nm.H OOO om. OO NO.N OH . OO O OH. O NO. O NN.H O ON. O HO.N ON O O ON. O OO. O HN.H Ou NN. +O ON.N OH O .H3 NHO O Eu OO\HE O2 O0 M O z OOHHOHOQOOOOH HmomEou HOOEHOOHH .ON NHSO OOHmO>pOO OOOHQOHHO .HHom oEOzOO OOH Scam HOOH OOOOOOSHO NOOSHOOO mo OOONHOOHOOOOOO HGOEOHOOHOOZ .OH OHOOH 53 resulting from the compost additions likely caused the re- duction in clipping Ca levels. The lack of significance in the nitrogen levels of the 1980 Huron (Oakville soil) clippings contradicts the findings of the July 1980 color ratings. Color ratings 59. Based correlate well with nitrogen content in turfgrass on the lower color ratings from the compost treatments, clipping N levels should have been correspondingly lower than those from the checks. A possible reason as to why this occurred may lie in the fact that the plot area was fertilized with 37 kg/ha urea 2 weeks prior to clipping collection but only 5 days before the July color rating. The 5 day period between urea application and the color rating was most likely not enough time to allow N conver- sion, uptake and response to occur. Fourteen days, on the other hand, would allow ample time for N conversion and uptake to occur. 3) Heavy metals The Oakville soil extractable micronutrient and heavy metal results (Tables 15 and 16) indicated that incorpora- tion of Detroit sewage sludge compost increased the avail- ability of heavy metals when compared to the checks. The extractable levels of these elements increased significantly in all cases in 1980, although the Fe levels were quite variable. In 1981 all compost treatments were found to have 54 .HOOH OOOOO OHOHHHsz 3O2 O.OOOOOQ NO HO>OH Om OOH HO HOOHmeHO NHHOOOHMHOOHO Ho: OHO OszHou O :HOHHz HOHHOH OEOO OOH OOH>OO OOOOE HOOEHOOHH+ O HO O ON O HN O 0.0 O OO O OO O ONH O OOO ON NON O ON O OH OO OH O 0.0 O HO O ON O OOH UOO Nmm ON OOH UO NH OO O o O O O.N O HO O OH O OO UO NON ON . OO OO ON OO OH O OH O N.O O mm OO Nm O ONH OO NNO OH . OOH O HN O HH UO HH O N.O O mm o OH O OO UO MOO OH OO OO O u H O H o O. O OH O N o O o OO ON O O O o H O H o O. o NH O H o O +o HO OH O Ema So OO\HE OO Ho Hz O0 :2 :u :N Om OOHHOOOQHOOOH Hmomsoo HOOEHOOHH .OOOH .OH NHOO OOHOEOO OOO ONOH .NN Hmsms< :o OHOOEHOOHH HOOOEOO ODOHOO> OHH: OOOOOEO HHom OOOm OOHm OHHH>OOO :O we OHO>OH HOOEOHOOHOH: .mH OHOOH SS .HOOH OOOOO OHOHHHSZ 3O2 O.OOOOSO HO HcOhOwwHO NHHOOOHOHOOHO Ho: OHO cezHoo O :HOHHZ OOHHOH OEOm OOH OOH>OO NO Ho>OH Om OOO OOOOE HOOEHOOHH+ O NN OH OH O O.N O OO OO OOH O OON ON NON O NN OH OH O 0.0 O NO ON OO OO OON ON OOH O OH O N o O.N o ON NH OO o NNH ON OO O ON OH ON O O.N O OO OO OOH O OON OH OOH o NH O OH o 0.0 0O OO OH OO O NON OH OO O O H N O N. O OH O NH O NN ON O O O H H O O. O OH N O +O HO OH O Ema Eu OO\HE OO H0 H2 O0 :2 :0 ON Om :oHHOuomHooaH Hmomaoo HOOEHOOHH .HOOH .OH MOOEOHQOO OOHOEOO OOO ONOH .NN Hmsma< :o OHOOEHOOHH , Hmomsoo msoHpO> OHH: OOOOOEO HHom OOOO OcHw OHHH>OOofizwmo OHO>OH HOOEOHOOOOHZ .OH OHOOH 56 significantly higher levels of all metals when compared with the two non compost treatments. The effect of dilution with depth of incorporation was apparent as the soil tests for most of these metals was lower for the 20 cm depth compared to the 10 cm depth incorporation at comparable compost application rates. Similar trends in extractable metals were apparent on the Pewamo soil (Tables 17 and 18), except that there was no difference in extractable Fe in either 1980 or 1981. Clipping contents for Zn, Cu, Cd and Ni concentrations in 1980 and 1981 at the Huron site (Oakville soil) were found to increase significantly with the application of 252 mt/ha compost when compared with the non compost treatments (Tables 19 and 20). At the 168 mt/ha compost addition, the deeper depth of incorporation significantly lowered Zn, Mn and Cd clipping levels in 1980, but not in 1981. Although the Oakville soil test results (Tables 15 and 16) indicated that significantly higher levels of extractable Fe, Cr and Pb were present in the soil, treatment clipping concentra- tions for each of these three metals were not statistically 35 reported that different from one another. Jones et al., increased solution concentration of Pb results in Pb con- centration increases in the roots only of perennial ryegrass plants. At both sod farms compost treatments appeared to decrease the Mn levels of clippings (Tables 19, 20 and 21). Increased 57 HO HcOanmHO NHHGOOHMHOOHO .HOOH OOOOO OHOHHHsz 3O2 O.OOOOOO NO HO>OH OO OOH HOOH Ohm CEHHHOU w HO.H:HHZ .HmHHOH OEwm mg“ wfifi>m£ mCNQE Hfl®EHQ®HH+ O OH O OH O ON O.HH O NOH OH OOH OOH ON OOO O OH O OH O NH N.O O OOH ON OO ONH ON OOH O HH OO N o HH 0.0 0O ONH OH NO OHH ON OO O NH OO N O ON 0.0 OO OOH NN OOH ONH OH OOH O OH OO O O OH H.O UO NNH OH HO OOH OH OO O O O N O O O. Oo OO O OH NHH ON O O O O H O O O. O OO O OH OO OH O OOO Eu OO\HE OO Ho Hz O0 :2 no :N Om :oHHOHOOOoOOH Hmonsoo HOOEHOOHH .OOOH .N NHsO :o OOHOEOO OOO ONOH .NN Hmsms< :o OHOOEHOOHH HmOOEoo msoHHO> OHH: OOOOOEO HHom sOoH NOHO NOOOO oEOzOO O mo OHO>OH HOOEOHOOHOH: .NH OHOOH 58 .HOOH OOOOO OHOHHHOZ 3O2 O.OOoszo OO HO>OH OO OOH HO HOOOOOOHO NHHOOOHOHOOHO Ho: OOO OEOHOO O OHOHHz HOHHOH OEOO OOH OOH>OO OOOOE HOOEHOOHH+ OO OH O O O ON O N.NH O OHH OO NH O OON OHH ON OOO OO OH O O O OH UO N.O O OOH O NH o NO NNH ON OOH OO OH O O UO NH 0O 0.0 O HOH OO OH O OO OHH ON OO OO OH O O O ON O 0.0H O NHH O NN O NOH NHH OH OOH O OH O N O OH O N.O O OO O ON O OO NOH OH OO OO N O N Oo O Oo N.H O ON 0O N O O NHH ON O o O O N O O O N. O NN o O +O OH NOH OH O BOO Eu OO\HE OO go Hz OO :2 :u :N Om OOHHOOOOOOOOH HOOMEOO HOOEHOOHH .HOOH .HN HmsOs< :o OOHOEOO OOO ONOH .NN HOOO3< :o OHOOEHOOOH HOOOEOO msoHpO> OHH: OOOOOEO HHom EOoH NOHU NOOOO oEOzOO O mo OHO>OH HOOEOHOOHOHE .OH OHOOH 59 HO HOONOOOHO NHHOOOHOHOOHO Ho: .HOOH OOOOO OHQHHHSZ 3O2 O.OOOOSQ NO HO>OH OO OOH OOO OEDHoo O :HOHHz HOHHOH OEOO OOH OOH>OO OOOOE HOOEHOOHH O O O O O.H O 0.0 OO O.H OO OO O NH OO OO O ON ON NON O OH O O.H OO O.N O O. 0 OO on HH UO NO O NN ON OOH O HH O O. O0 0.0 u N. 0 OO on HH 0 NO O NO ON OO O NH O O.N O 0.0 O H.H OO OO O NH O OO O ONH OH OOH O OH O N.H 0O H.O 0O O. 0O HO O NH O OO O NO OH OO O a O N. OO N.N O.N. O OO O O O OO O HN ON o O NH O N.H O O.N O O. O NO O O +O OO O HOH OH _ o .H3 NNO O\On Eu OO\HE OO Nu Hz O0 :2 no :N Om :oHHOpomuoocH Hmonsoo HOOEHOOHN .HOOO OHHO>OOO OOO EOOO OOOH .HO NHSO OOHmO>HOO OOOHOQHHO OOOHOOSHO NOOSHOOO mo mcoHHOhHOOoaou HcOeOHOOHOHZ .OH OHOOB 60 HO HOOHOOOHO .HOOH OOOOO OHOHHHOZ 3O2 O.OOOOOO NO HO>OH Om OOH NHHOOOHOHOOHO Ho: OOO OEOHou O :HOHHz OOOOH OEOO OOH OOH>OO OOOOE HOOaHOOHH+ O N O O. O m.N O O. O HO O OH O HO OO ON NmN O N O O. O 0.0 OO m. O Om OO mH OO Om NO ON OOH O N O O. O N.O O m. O om OO mH OO Om OO ON OO O N O O. O N.N OO O. O Om OO mH O Om OO OH OOH O N O O. u 0.0 O O. O NO OO OH OO mm NO OH OO O N O O. O m.N u N. O NO O NH O om mm ON O O N O N. O N.N u m. O mO O NH +O Om Nm OH O .H3 NOO O\OO Eu OO\HE OO Ou Hz Ou :2 so ON Om OOHHOOOOOOOOH HOOOEOO HOOEHOOOH .HHoO OHHO>OOO OOH EOOO.HOOH .O OOOEOHOOO OOHmO>HOO OOOHOOHHO OOOOOOsHO NOOOHOOO mo mcoHHOOHOOOOOO HOOEOHOOOOHZ .ON OHOOH 61 .HOOH OOOOO OHOHHHOZ 3O2 O.OOUOOO NO Ho>OH Om OOH HO HOOOOOOHO NHHOOOHOHOOHO Ho: OHO :EOHou O OHOHHz OOHHOH OEOm OOH O=H>OO OOOOE HOOEHOOHN+ O H.O UO O. O N.O O O. O ON O m.m O «O O NO ON Omm O 0.0 OO O. O N.N UO N. O ON O 0.0 O NN O NO ON OOH O 0.0 OO O. OO O.N u N. O HN O O.N UO ON O we ON OO O N.O u O. O N.O OO O. O ON O 0.0 O OO O OO OH OOH O 0.0 O N. UO N.N UOO O. O «N O O.N UO ON O HO OH «O O O.N O O. u O.H u N. O OO O O.N UO ON O OO ON O O O.N O O. o O.H u N. O OO O N.N u HN +O OO OH O .H3 NOO O\OO Eu OO\HE Om H0 H2 OO :2 :0 ON Om :oHHOOOQHouaH Hmomaou HOOEHOOOH .HHom oEOzOm OOH SOHO HOOH .ON NHOO OOHOO>HOO OOOHOOHHU mmOOOOOHO NOOOHOOM mo mcoHHOOHOOUOOO HOOHOHOOOHOHZ .HN OHOON °paaueque sen q1M018 31ml noguezodloau: usodmoo go 3191 Buyseelau; qqgm neqz peteeAaJ £11991: (1:05 omeMad) e115 znteM aqn 1e sptagx Bugddgtg '(zz atqel) lsodmoa eqn go uogzelodxoou: 191;e 5199A z AIGleIXOJddB suogneooI 101d sq: max; sBugddgta Burnaattos Aq pe1en19Aa SBM qlmoxfi ssexfientq Aqanluex uo nsodmoa eBpnIs afiemes 1101193 go 139;;9 mien BuoI eql ‘SpIGIA Buxddgto p191; pue q18ue11s p03 (V SS 5358918 112 10; SBBJSAB palaprsuoa SBM mdd 1'2 30 uo;1911ue3u03 Buyddgta pg 9 SIOUIIII uI °mdd Lg aq 01 L p9110d91 ueeq seq enase} {I91 u; uogaonpaa pteyx 38910; %sz 9 unoqe Buglq 01 Alesseoeu uozuellueauoa Buyddgta p3 eql 6I°n3 10; mdd 0v - SI pue ‘uz 10; wdd ooz - 0v ‘uw 051 - oz ‘93 10; mdd 032 - 07 se peasgt ueaq aAeq sBu;dd:13 gin; u; SlUGIllflUOlDIm IBIQAQS 10; seBuex ayxonuou eql ‘SBUIddIID sq; u; azetnmnaae 01 IBdeB non pgp stenem aseq: go SIGASI 31x01 ‘pauou 913M stenam IBJGAGS u; saseexau; zueoygyufiys AIIBDIlSIlBlS atIqM '(uoan) Ixos SIIIAXBO aq: no 1919918 Atuqfiyts SBM exendn [919m sxeedde 1: ‘seurs prey; on: sq: ueemneq apem sen nestledmoo 19311511815 ou anoanV Ig‘SdOJD IBIGAOS uo pa110d91 uaeq seq SIGAGI p3 pe1eAete Aq pesneo snot; -911ua3u03 geat um palatalxoa AIaAguefieN 'sfiugddrto sq; u; nuasaxd Apeelte um sq; peanIIp Atdmgs eAeq Aem nsodmoa sq: Aq unoqe 1q3n01q q1M018d01 pesealau; sq; 10 eqeadn um 01 agnsguofienue ueaq eAeq Aem IN 10 p3 ‘ng ‘uz go XIIIIqBIIBAB Z9 63 Table 22. Dry clipping weights of Kentucky bluegrass har- vested from the two sod farms in the summer of 1981.* Treatment Huron Waltz compost incorporation OEEVTTle fiEWamo fine sand sandy clay mt/ha cm grams/plot o 10 56.5 b+ 9.5 c 0 20 57.6 b 8.5 c 84 10 62.5 b 27.1 b 168 10 58.7 b 56.8 a 84 20 77.1 ab 28.5 b 168 20 111.5 a 40.2 b 252 20 87.5 ab ---- 336 20 ---- 71.0 a +Treatment means having the same letter within a column are not significantly different at the 5% level by Duncan's New Multiple Range Test. *Date of harvest, July 29, for Pewamo soil, September 6, for Oakville soil. 64 At the Huron site (Oakville soil) clipping yield results were less clear. Substantial variability between replications existed for each treatment. The cause of the variability ap- peared to be due to drought-like conditions which developed at this site in late June and early July of 1981. Although the turf in the high compost treatment plots (252 mt/ha 20 cm) appeared to remain actively growing for a longer period of time, dormant turf was observed in all plots by early July. Turf recovery from the drought-like conditions, though appear- ing slightly better in the compost-treated plots, was highly variable between replications. Sod grown on organic soil is generally mature enough to be harvested at an earlier date than sod grown on a mineral 5 Table 23 shows the relative differences in soil soil. organic matter levels resulting from the various compost treatments. As expected organic matter levels rose with in- creasing compost addition at each site and decreased with increasing depth of incorporation. A two-fold increase in the soil organic matter level was noted at both sites with the highest rate of compost additions compared to the checks. Compost incorporation was found to have no effect on sod shear strengths at either location at the 5% level (Table 23). When the 10% level was examined,snxishear strength treatment means at the Waltz site (Pewamo soil) were found to increase with increasing rate of compost application. Significantly higher sod strength values have been recorded 65 .HOOH OOOOO OHOHHHOZ 3O2 O.OOOOOO NO HO>OH Om OOH HO HOOHOMOHO NHHOOUHOHOOHO Ho: OOO OEOHou O OHOHHz HOHHOH OEOm OOH OOH>OO OOOOE HOOEHOOONO O O.HO O O.HH ---- --- ON OOO ---- --- O O.OO O O.O ON NON O O.OO OO O.O. O N.OO O O.O ON OOH O O.HO O O.O O O.NO O O.O ON OO O O.OO O O.O O H.OO O N.O OH OOH O O.HO OU O.N O O.OO O O.O OH . OO O O.OO O N.O O O.NO u O.N ON O O O.OO O N.O O N.OO Ou O.H OH O OO O OO O OO OONOO OHWMMOOO wmwwmmo OHMMWOOO wmwwmwo OOHOOOOOOOOOO HOOOEOO oEOzOO OHHH>OOO HOOEHOOHN .OHHom OHHH>OOO OOO oEOzOO OOH :o OOOHEOOHOO HOHHOE UHOOOOo HHom HOOOOOQ OOO OHOOOHHO OOOOm Oom .ON OHOOH 66 on a compost amended Galestown sandy loam soil when compared to a standard fertilizer treatment (561 kg/ha 10-20-20 surface applied) on 13 month old Kentucky bluegrass sod.58 C. Greenhouse Studies 1) Seed germination To determine the quantitative effect Detroit sewage sludge compost had on seed germination a greenhouse pot study was initiated. The soils from the 2 sod farms plot locations were mixed with the compost in volumetric proportions of 0, 25, 50 and 75% and were maintained at 2 irrigation levels. The 2 irrigation levels (high and low) consisted of 25 or 100 ml of water applied twice weekly. Figures 1 and 2 show the effect of Detroit sewage sludge compost on perennial ryegrass seed germination. On the Oak- ville soil (Huron) maintained under low irrigation conditions, seed germination was decreased with 50% or more compost (by volume) when compared with the control. At the high irriga- tion level seed germination was decreased significantly only when the compost treatment level reached 75%. On the Pewamo soil (Waltz) seed germination was signif- icantly increased at the 25 and 50% compost treatment levels when maintained at the low irrigation level. However, at the 75% compost level under low irrigation the number of seeds germinated was not significantly different than the check. At the high irrigation level, seed germination was (A \l 170 g 7.— O {igh irrigation Qt \ . a o I 51.50 Low irrigation S L.S.D at E E 37.: 14.2 3 3140 k} U) 2‘3 o $4 5.30 0 Z #-— C 12 .___ 0 25 50' 75 PERCENT COMPOST, VOLUME Figure 1. Number of flanhattan perennial ryegrass seeds germinated per pot in a Oakville fine sand soil at 2 irrigation and h compost levels replicated 4 times. SEEDS GERHINATED / POT 0F ”UMBER 160 150 140 130 110 CD ( D O 0 High irrigation 0 Low irrigation .\ O l . L.S.D at 5% = 15.5 db 23 50 PERCENT COMPOST, VOLUME Figure 2, Number of Manhattan perennial ryegrass seeds germinated per pot in a Pewamo sandy clay loam soil at 2 irrigation and A compost levels replicated 4 times. 69 not affected at the 25 or 50% treatment level but was signif- icantly reduced at the 75% compost treatment level when com- pared with the check treatment which was more similar to the results on the Oakville fine sand. Prior to addition of the wetting agent, water applied to the compost amended soils resulted in beading of the water upon the soil surface. After saturating the soil by capil- lary rise and applying the wetting agent as a soil drench, beading of the water of the soil surface was no longer ob- served. This suggested that application of the wetting agent together with saturation of the soil prevented reoc- currence of the hydrOphobic condition. In the absence of a hydrophobic soil condition, the reduction in seed germination observed in both soils was most likely due to salt loading of the soil. The soluble salt content of the compost utilized in this study was found 45 found that a to range from 2.8 to 4.0 mmho./cm. Murray compost with a soluble salt concentration of 3.3 mmho./cm, under poor soil drainage conditions, caused a reduction in Kentucky bluegrass seed germination. In this study, on the Oakville soil (Huron) where drainage was not a problem, the finding that a higher percentage of compost was required to bring about a significant reduction in seed germination at the high irrigation level, suggested that the high irrigation level diluted or caused leaching of the salts present in the compost to a greater degree than the low irrigation level. 70 Soil physical conditions may have been responsible for some of the reduction in seed germination. Because of the large amounts of wood chips present in the compost, firm seed contact with the soil could not be assured at the 50 or 75% compost (by volume) treatment level. Mays et al.,43 have reported that incorporation of municipal compost pre- vents the preparation of a firm seed bed which results in a reduction of sorghum seed germination. The significant increase in seed germination observed at the low irrigation level on the Pewamo soil at the 25 and 50% compost levels may be attributable to the lack of a sur- face crust on these treatments. The untreated Pewamo soil, when allowed to dry out, developed a hard surface crust which appeared to inhibit seed germination and growth. Mix- ing compost with the soil promoted a friable soil condition which did not result in the formation of a surface crust upon drying. The 75% compost treatment level was not significantly different from the check under low irrigation conditions possibly because the inhibitory effect of the salts upon germination offset the advantageous mulching effect of the compost. Based on work which has shown that, in some instances, smaller seeds appear to be more susceptible to smothering 59 reduction in from compost applications than larger seeds; the seed germination of Kentucky bluegrass could be even greater than the reduction observed for perennial ryegrass 71 in this study. Interpolating field observations with the results of this study is difficult considering the wide differences in moisture regimes, soil densities and the fact that no wetting agent was applied in this field. 2) Clipping weight and N study The effect of compost on the growth of perennial rye- grass at 3 N levels is presented in Tables 24 and 25 for Oakville (Huron) and Pewamo (Waltz) soils, respectively. Nitrogen content of the clippings at Weeks l4, l8 and 34 for select treatments is presented in Table 26. When no supplemental N was added, increasing amounts of compost increased tOpgrowth for all but the highest compost treat- ment at Week 14 on both sites. The reduction in topgrowth at the highest compost rate appeared to be due to a reduction in seed germination coupled with delayed seedling emergence. Seedling emergence appeared to be more severely delayed in the Pewamo soil. From Week 18 to Week 34 at N treatment of 293 and 586 kg/ha/month, the effect of compost on dry matter production was somewhat variable. The presence of powdery mildew (Erysiphe graminis) in some of the pots together with a severe infestation of aphids in the greenhouse during this time may have influenced topgrowth. However the occurrence of these problems appeared to be independent of treatment. On both soils it was not until Week 34 that a clear trend 72 mo.o oa.o oH.o mo.o mo.o mo.o HH.o Ho>oH wm .n.mtq mm.H mm.H oH.H mo.o Ho.o ev.H mm.o 0mm oem cm.H mN.H «N.H em.o mm.o me.H mH.a owm cum no.H mH.H mo.H Hm.o om.o 0H.H HO.H 0mm omH xmo :m :M omsozcoomm may cw esopm mmmpwoxu Hmficcouom :muumncmz mo muzmwoz mnfimmwfio Ayn .em oflnmh 73 oH.o oo.o mo.o mH.o so.o mo.o mo.o Ho>oH wm .n.m.q mm.H mN.H mH.H mm.o um.o oa.H mn.o omm ovm om.H um.H cm.H om.o Mm.o mo.H mo.a omm ohm mo.H Hm.H mw.o mo.H an.o HH.H mm.o omm owH vo.H v~.H cH.H 0H.H mm.o ON.H 0H.H omm om om.o oo.H m~.H 0H.H m¢.o em.H oe.H omm o «O.H mm.o eo.H vw.o om.o mo.o um.o mom ovm Hm.o mm.o vu.o mn.o me.o om.o oc.o mam ONN mm.o mm.o mn.o vm.o Hm.o ow.o mo.o mam omH wm.o mu.o mo.o mn.o N¢.c mm.o mw.o mam om we.o om.o mc.o Bu.o ov.o mm.o mw.o mam o mo.o oc.o Hm.o Hm.o mm.o um.o Hm.o o ovm mm.o oo.o em.o mm.o em.o mm.o om.o o cum mm.o vv.o Hm.o He.o o~.o mm.o w~.o o omH mm.o om.o mm.o wv.o «N.O m~.o em.o o co mH.o mH.o mH.o om.o mH.o om.o mN.o o o pom\msmpm nuaoa\m:\mx m:\uE mm em om cm mm mm «H somehow: amoQEoo x003 acoEumouH uzmwoz mcfimmwao xyp .moumu :owumofiamnm :mwouufic zazucoa m an umomsoo no“: popcosm Hwom EmoH meo xpcmm oemzom n ma omzozcooum can a“ czoum mmmhmoxa Hmwccouoo :muumccmz mo mu:MHoz mcfimmflao zen .mm manna 74 oe.o mm.e wm.e cm.c me.o Ho>ma am .a.m.4 e~.e oo.m MH.m ao.e aN.m 0mm a. cam mm.e eo.e me.m mm.e ea.m cam owa mo.m No.e am.m He.e we.e 0mm o me.m mm.m mm.N mH.m wa.~ mam cam ma.m No.m mN.m mo.m ma.~ mam owH ee.m oe.m He.m HN.m ma.~ maN o NH.m ON.N mm.~ eo.N NN.N o cam oo.m mH.m NO.N me.~ Ne.N o owe NN.N mm.~ OO.N mo.~ mN.N o o mmcfimmflao ca 2 ucooaom npzoe\m:\mx m:\us .mxz em .mxe mH .maz eH .mmz em .sz «H EmoH Nmao apcmm osmzom wcmm pmfim oflfiw>xmo Ho>oH z . «momsoo ucosumoph .mxooz em mo ma .eH wo weapon :owumnsomw cm Houmm mmcfimaflao mmmpmoxn Hmwccohoa announce: a“ :omonufi: Hemopoa one :o mucoEumouu :owouuw: can umomEoo mo uoommm .om oaamh 7S emerged showing that compost treatments up to 270 mt/ha stimulated perennial ryegrass growth. The lack of significant differences in the N content of the clippings at Week 34 for the 0, 180 and 540 mt/ha compost treatments receiving 293 kg/ha/month N, on both soils, suggested that N alone was not responsible for the 57 eval- increase in dry matter production. Terman et al., uating the effect of compost upon forage yields found that yield increases in 'Kentucky 31' tall fescue were caused by the liming effect of the compost on an acid soil. Minera- lization of P and K present in the compost may have supplied the additional P and K required for increased growth stimu~ lated by the nitrogen fertilization. Soil tests revealed that both soils initially were low in K. Depletion of the supplemental K by leaching may have been great enough by Week 34 that the non-compost amended soil treatments con- tained insufficient K necessary for maximal N response to occur. A typical compost contains approximately 0.2 percent K, on a dry weight basis.32 Oakville clipping nitrogen levels at Week 14 revealed that when no supplemental N was added turf N levels increased with increasing compost addition. This suggested that mineralization of organic N in the compost was taking place. Mineralization of compost at 14 weeks in the greenhouse would infer that the chlorotic turf observed at the Huron site in the summer of 1980 was not caused by wood chip nitrogen immobilization. Mineralization of N from sewage sludge 76 compost has been reported as early as 5 to 7 weeks after soil 24 Reductions in N content of clippings observed at mixing. Week 14 under high N treatment level might suggest that excessive water was added to the pots and that some leaching of the supplemental N had occurred. C. Soil Physical Properties 1) Bulk density, saturated water flow, wood chip content Soil cores collected from the 20 cm treatments in the field were analyzed for soil bulk density, saturated hydrau- lic conductivity, percent by volume wood chips and soil moisture content at various moisture matric potentials above 1 bar. The cores were collected approximately 2 years after the compost had been incorporated into the soils at the 2 sod farm sites. Results of the physical determinations made on these cores are presented in Tables 27 and 29 and illus- trated in Figures 3, 4, 6 and 7. As expected soil bulk density decreased and the volu- metric percentage of wood chips present in the soil increased with increasing compost application (Table 27). The response of compost on soil density appeared to be linear on both soil types (Figure 3). The presence of the small amount of wood chips in the untreated plots was due to contamination of one of the plots at the Waltz site (Pewamo soil) and two of the plots at the Huron site (Oakville soil). Contamina- tion occured during the incorporation of the compost and was limited to small amounts around the edges of the plot areas. 77 .Hflom oHHfl>xmo ecu scum .mN ponsoumom use Hwom oamzom map Eouw .NN umsmz< wouooaaoo mopouN .opoo HHom :fi venom EE OO.N can» poumoew mmwzo poo: mo owmucoouom 0732350?A mopfim ozu one macaw mcomwummaou .mfimmn mde :o mama ma- can mm;$.:oozuon mam; noun: mo uczoEoH am ecu um pcopommflp xaucmowmwcmHm Ho: ohm :ESHoo m :«gufiz popuoa 05mm may mcfi>ms memos acosumope+ m m.m m m.n m H.mH p HN.H om Nmm n m.m m w.o m “.NH o om.H om wcH o >.H an N.m n H.HH a He.H om em v ~.o n n.m n m.m m Hm.H om o ucmm ocflm oaaw>xmo m m.eH m N.mH a m.NH o wo.~ om omm n 0.0 an m.~a m m.o n mN.H om wcH on m.m a m.m m n.m pm wm.~ om em o N.o a o.m m w.N +m mv.H ow o EmoH xmflo chmm osmzom w w u:\ao oo\m Eu m:\us mmfino woo: poem: wa>flpo3pcoo Newmcow xossfio> xoanmafim>m oflazmap»; xasn :oflumuomuoucw umoaeoo woumHSHmm “coaumoue oumfi :H macaw was Eouw couooaaoo moaoo :o owns m¢0wumcfiahouw .mea mo Hoaezm e Hmonmsea Hmom .nm QHAMH [G/CC] BULK-DENSITY 1.60 1.50 1.404 1.30‘ m HURQN , Oakv1lle 8011 u 1.20‘ - (D 5551,11?) soil J 1.104 0.0 84' 168T zsé 336' COMPOST [MT/HR) Figure 3. The effect of compost on soil bulk density of an Oakville fine sand and Pewamo sandy clay loam soil when incorporated to a depth of 20 centimeters. (CM/HR) K 79 El HURON Oakville soil 0 HHLTZ Pewamo soil I 0.0 841 168' 255 336 COMPOST [MT/HR] Figure 4. The effect of compost on saturated hydraulic conductivity of an Oakville fine sand and Pewamo sandy clay loam soil when incorporated to a depth of 20 centimeters. 80 Wood chips content at identical rates of compost appli- cation appeared to be consistently higher at the Waltz site though no statistical analysis between the two sites was performed. A slower rate of decomposition of the smaller chips may have been occurring at the Waltz site due to the poor drainage characteristics of the Pewamo soil. A more likely explanation is the possibility that the compost de- livered to the Waltz site had a higher wood chip content than the compost delivered to the Huron site. Wood chips, when incorporated into the soil, can improve soil physical properties. Application of 22.4 mt/ha wood chips to a Merrimac sandy loam soil increased capillary porosity CBC and soil aggregation (> 1.00 mm) of the soil while slightly decreasing soil bulk density.42 Saturated hydraulic conductivity was increased on both soils types with the addition of compost (Table 27). The addition of 336 mt/ha compost to the Pewamo soil resulted in over a 4-fold increase in saturated water flow when com- pared with the non-compost treatment. The increase in sat- urated hydraulic conductivity on the Oakville soil was not as dramatic due to the naturally higher saturated water flow of the non-amended soil. The increase in saturated hydrau- lic conductivity with compost application can be attributed to the increase in total pore space (decreased bulk density) of both soils. The moisture retention curves of both soils (Figures 6 and 7) indicated that a substantial increase in 81 the number of large pores occurred. Large pores increase saturated flow by reducing water flow tortuosity. 2) Field infiltration Infiltration in the field was evaluated utilizing double ring infiltrometers. On the Oakville soil the total amount of water entering the soil in a 1 hour period was recorded while on the Pewamo soil the total amount of water infiltrating over a 3 hour period was determined. The infiltratiOn determinations were performed approximately 2 years after the compost had been incorporated in the 2 soils. Compost treatments on the Oakville soil were found to have no significant effect on the infiltration of water into the soil (Table 28). On the Pewamo soil, compost treatments were found to significantly increase in infiltration of water into the soil over the three hour period (Figure 5). At the 10 cm depth of incorporation, infiltration over the 3 hour time period was found to increase with increasing addition of compost but no significant difference between any of the 10 cm incorporation treatments could be claimed. At the 20 cm depth of incorporation, all compost treatments had significantly higher total infiltration than the non- compost treatment, but no significant difference existed among the 20 cm compost incorporation treatments. 'Infiltration of water into the soil is affected in part by the stability of aggregates. Disintegration of aggregates 82 Table 28. The effect of compost on infiltration of 2 soils 2 years after compost incorporation. Treatment ‘——————total infiltration compost incorporation Oakville Pewamo fine sand sandy clay loam mt/ha cm cm/hr cm/3 hr 0 10 24 a* 0.9 bc 0 20 25 a 0.6 c 84 10 17 a 1.8 bc 168 10 16 a 2.9 b 84 20 22 a 5.2 a 168 20 17 a 5.2 a 252 20 16 a --- 336 20 -- 6.0 a * . Treatment means having the same letter within a column are not significantly different at the 5% level by Duncan's New Multiple Range Test. +Compost incorporated August 1979, field infiltration deter- minations ran July 1981. TOTHL INFILTRRTION (CM/3 HR] d i //// 20 CH INCORPORQTION \\\\\\\\\\\\\\\N \\\\ 10 CH INCORPORRTION _ W V LO 2.». —\\\\\\\\\\\\\\\\\\\\\\\\\\\\m 0.0 84 168 COMPOST (MT/HR) Figure 5. Amount of water infiltrated over a 3 hour period on a Pewamo sandy clay loam soil as influenced by compost incorporation. 84 by wetting causes soil particles to fill in soil pore space which blocks the downward movement of gravitational water. Increased aggregation and aggregate stability brought about by compost application22 may be partly responsible for the in- creased infiltration of water observed in this study. Reduced water flow tortuosity, resulting from the presence of larger size pores in the compost amended plots may have also been responsible for the increased infiltration observed on the Pewamo soil. 3) Soil moisture The effect of compost on the soil moisture character- istics of the two soils is presented in Table 29 and illus- trated in Figures 6 and 7. At a matric potential of -1 bar and above, soil moisture content was evaluated utilizing soil cores collected from the field. At the -15 bar matric potential soil water content was determined on disturbed soil samples. Figures 6 and 7 clearly show that compost incorporation shifts the moisture retention curve of the soil to a higher water content at a given matric potential. On the Pewamo soil, soil water holding capacity was increased 23.1% over the check with the incorporation of 336 mt/ha com- post while on the Oakville soil a 14.5% increase over the check in soil water holding capacity was observed with the addition of 252 mt/ha .compost. - The amount of water held between -0.33 and -lS bars is most often considered to be the amount of soil water 85 Hfiom onRSHmflucz cm wocwEHouow pan oo.H- one seam Hmma .mm monsounom can Hfiom ceased may Eoem meH .NN umaw3< wouooafioo moHOUN .paowm on“ anw wouooaaoo mohoo OH 00.0 EOHW HGQHGOU HOHQZ .Hnom QHHH>xmo m.m m.mH m.oa m.ma H.¢m H.Hv mmm «.0 «.NH ~.mH H.OH m.om m.mm woa c.v o.m m.m m.NH 0.0N m.om em ¢.m o.o N.N N.HH m.m~ 0.0N o pcmm mafia oHHfl>xmo 0.0H m.mm N.vm m.om H.He o.Hm omm m.mH m.e~ w.mm n.m~ m.om ~.wm woa m.- m.HN N.NN e.e~ a.cm o.mm em w.HH m.m~ w.o~ «.NN N.¢N m.m~ o w m:\us EmoH xmao chmm osmzom oo.ma- oo.H- mm.o- oH.o- mo.o- oo.o mmmmnv Hmflucouom oflupmz “monsou Hwom mmme\poum3 mmme “.momxu Hflom N we mofiumwaouomamgo :0wucouoh Roam: one so umOQEoo mo uoommo 0:9 .mm oases 86 Do.—u F b .muouoswucoo om mo cunou a co umoaaoo mo moumu q saws newsman pawn mafia oHHfi>xmo cm mo .unwams hm .muaumwoe ucmuuoa mmmum>< .o mmswam Awmcm. 4¢_pzmhom uuxpcz om. .. P X 0 ¢:\h: ¢:\h: c:\h: ¢:\»: uww co— co 6) Q '+ .x 1109 SSUN/HBlHM SSUN 87 .mumumefiunmo ON mo nuaop m on umomaoo mo mmumu q :uaz vvamEm Hfiom Emoa hmao xpamm oEmBmm n no .unwaoa ma .muaumfioa unmoumm mwmum>< .m muswfim Ammcm: ._¢:2m:om Saba: om... oo.o b I P h — OO._ .. p h b h h mo. 2. mg. ON. o/ C mNo ./ om. XI/X mm- /x 3.. $5: 8m x 5.2: 8. + mv $5: 3 a. om . 5.2: a 9 mm. 'IIOS SSUN/HBIUM SSUN 88 available for plant uptake.28 The amount of water held between -0.33 and -15 bars was found to increase with in- creasing amounts of compost addition on both the Oakville and Pewamo soils (Table 27). The addition of 252 and 336 mt/ha compost to the Oakville and Pewamo soils respectively, resulted in a 3.4% increase in plant available water to the Oakville soil and a 9.2% increase in plant available water to the Pewamo soil on a mass basis. The increased -15 bar soil water content with compost addition was due to increased sorption of water caused by elevated soil organic matter levels. At -1 bar and above, soil water content increases were due to increased sorption of water caused by elevated organic matter levels, and to changes in pore size distribution caused by increased soil aggregation and/or, the presense of wood chips in the com- post.22, 42 31 and Epstein22 have reported that Gupta et al., digested sludge amended soils undergo an increase in water holding capacity but not available water. The increase in available water found in this study reflects, in part, the use of undisturbed soil cores in evaluating soil moisture retention. Collection of undisturbed cores from the field allows i£.§l£2 changes in pore size distribution (due to increased aggregation) to be evaluated. Gupta et al., and Epstein in their work utilized disturbed soil cores which do not allow pore size distribution changes due to aggregation to be evaluated. 89 4) Soil compaction Compression of the soil cores up to a pressure of 4.00 bars with the Instron Universal Testing Machine revealed that the 168 and 336 mt/ha compost treatment cores could be compressed significantly more than the check treatment cores (Table 30). However, the final compressed bulk den- sity of either of these two treatments was substantially lower than the bulk density of the check treatment soil cores. This suggests that fine textured soils amended with compost, may be able to better withstand the development of compacted soil conditions caused by frequent passing of sod equipment over the field. 90 Table 30. Decrease in soil bulk density of a compost amended Pewamo sandy clay loam soil due to a compactive force of 4.00 bars. initial final increase in QBEEEEE. bulk density bulk denSity bulk density mt/ha grams/cc 168 1.25 1.45 0.20 a+ 336 1.09 1.28 0.19 a 84 1.39 1.57 0.18 ab 0 1.50 1.64 0.14 b +Means followed by the same letter are not significantly different at the 5% level according to Duncan's New Multiple Range Test. SUMMARY AND CONCLUSIONS The objectives of this investigation were to evaluate the impact of Detroit sewage sludge compost on: 1) turf- grass growth for sod production, and: 2) select soil chem- ical and physical properties. The objectives were imple- mented by setting up field plots at 2 sod farms in south- eastern Michigan and by running 2 greenhouse studies. Two contrasting soil types, an Oakville fine sand (Huron site) and a Pewamo sandy clay loam (Waltz site) were present at the 2 sod farm plot locations. Field observations revealed that the incorporation of Detroit sewage sludge compost can delay the emergence and early establishment of Kentucky bluegrass under dry soil conditions. The compost, when allowed to dry out, develops hydrophobic properties which restrict water move- ment into the soil. In the absence of hydrophobic soil conditions (greenhouse study), the effect of compost on seed germination appears to be minimal. At volumetric rates of 50% compost (a rate equal to the highest rate of compost incorporation in the field) seed germination was substan- tially reduced only at the low irrigation level on the Oakville fine sand soil.: At the 25% compost level no sub- stantial reduction in seed germination was observed at either irrigation level on either soil. 92 The greenhouse study findings suggest that as long as care is taken to not allow the development of hydrophobic soil conditions seed germination reduction should not be a problem on compost amended soils. The presence of supple- mental irrigation at the time of seeping together with the application of a wetting agent should insure that soil hydrophobic conditions do not develop. The presence of compost in the Oakville fine sand soil (Huron) during the first growing season following incorpor- ation resulted in turf growth that was slightly yellow in color. Nitrogen immobilization caused by the presence of wood chips in the compost may have been responsible for the chlorotic color of the turf. However, analysis of turf- grass clippings in the summer of 1980 revealed that no significant difference in N content of the clippings existed among all treatments. Additionally, the greenhouse clipping-N study results indicated that mineralization of the nitrogen from the compost occurs as early as 14 weeks after incorporation of the compost. Analysis of the Huron clippings in 1980 for Cd, Pb, Ni and Cr revealed that no heavy metal accumulated to a level that could account for the chlorotic turf growth. The exact cause of the yellow turf color could not be isolated. By the second growing season, chlorotic turf growth was not observed on the compost amended plots of the Oakville soil.‘ 93 The effect of compost as a slow release fertilizer was readily apparent at the Waltz site (Pewamo soil) and in the greenhouse clipping-N study. Because of more frequent fertilizer applications made to the plots at the Huron site (Oakville soil), nutrient mineralization of the compost was partially "masked" at this site. For this reason, the improvement in turf quality and color caused by compost incorporation was not as dramatic at the Huron site as it was at the Waltz site. In 1981 N, P and K content of the clippings at the Waltz site together with the 1981 soil test results clearly indicated that the improved turfgrass quality and color observed on the compost treated plots was due to increased availability of N, P and K in the compost. The presence of heavy metals in the compost did not appear to present a limitation to sod growth at the rates applied in this study. Cadmium and Ni were found to increase significantly in clippings with compost incorporation, but the increases did not appear to be great enough to affect turf growth. In the soil, Cd, Ni, Cr, and Pb increased with increasing compost application. The 20 cm depth of incorporation was found to successfully dilute the presence of the metals in both soils when compared to the 10 cm depth of incorporation. Application of compost was found to raise organic matter content and pH of both soils. With the incorporation of 336 mt/ha compost to the Pewamo soil and 252 mt/ha compost to 94 the Pewamo soil and 252 mt/ha compost to the Oakville soil, a 2-fold increase in soil organic matter was noted on both soils. The effect of the compost on soil pH was dependent on the pH and CBC of the soil prior to compost addition and the amount of compost added. In this study the liming effect of the compost was more evident on the Oakville soil because of the lower initial pH and buffering capacity of this soil. The addition of Detroit sewage sludge compost improved the physical properties of both soils into which it was in- corporated. Changes in soil physical properties appeared to be more pronounced on the finer-textured Pewamo soil. On both soils, application of compost decreased soil bulk density and increased saturated hydraulic conductivity. On the Pewamo soil, applying a compactive force of 4.00 bars compressed compost amended soil cores more than unamended soil cores. However, the final bulk density of the compost treated cores was lower than the unamended cores. This in- dicates that compost amended soils will most likely maintain a lower soil bulk density than non compost amended soils under similar compactive conditions. On the Pewamo soil, the addition of compost increased water intake in the field. On the Oakville soil, where water intake is naturally very high due to the presense of a large amount of sand, compost incorporation had little influence on water intake. The increased water intake and saturated hydraulic conductivity of the Pewamo soil result-' ing from compost incorporation may improve the drainage 95 characteristics of this soil providing tile drainage is present in the soil to accept the increased water flow. The addition of compost increased the water holding capacity and the amount of plant available water in both soils. At both sites the highest rate of compost applica- tion increased plant available water approximately 2-fold. At the Huron site (Oakville soil), turf in the compost amended plots was able to remain actively growing for a longer period of time under drought stress conditions than turf in the check plots. Application of Detroit sewage sludge compost to min- eral soils does not appear to adversely affect sod growth. The value of the compost as slow release fertilizer and \as a soil amendment was readily apparent in this study. Disposal of Detroit sewage sludge, by composting, with subsequent application of the compost to mineral soil sod farms, appears to be a practical alternative to incineration of the sludge now practiced by the city of Detroit. 10. 11. LITERATURE CITED . Angle, J. S. 1978. Use of sewage sludge compost for the establishment of turfgrass. M.S. Thesis. Univer- sity of Maryland. . Angle, J. S., D.CL Wolf and J. R. Hall III. 1981. Turfgrass growth aided by sludge compost. 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