Community waste management programs that include the composting of sewage sludge and yard wastes have become a necessity. Using these composts provides many benefits; however, increased levels of organic matter may reduce the effectiveness of preemergence herbicides. Determining how herbicide application rates may need to be adjusted when composted waste is incorporated into the soil may permit the use of these amendments without any decrease in weed control. This experiment examined the effect of two types of compost (composted sewage sludge and composted yard waste) on the weed control provided by four preemergence herbicides. The soil was a Hagerstown silt loam amended with 10%, 20%, or 30% compost by volume. Each mix was placed in half-gallon cardboard milk cartons. The cartons were seeded at 1/2 and 1/4 inches with a mixture of broadleaved weeds and grasses. Each soil mix was treated with simazine, oxyfluorfen, oryzalin, and metolachlor at two rates. Control was evaluated both visually by number and by the dry weight of the harvested weeds. Preliminary results indicate composted sewage sludge causes a greater reduction in herbicide efficacy than composted yard waste. Oryzalin and metolachlor were affected less than oxyfluorfen or simazine. The experiment was repeated using lower application rates. In one replication the soil mixes from the previous experiment were used. The second replication used a Hagerstown silty clay loam soil with fresh compost. The results of this experiment will provide preliminary information for future field studies designed to determine if the application rates of preemergence herbicides need to be adjusted when fields are amended with composted organic matter.
Jennifer A. Johnson, Larry Kuhns, and Tracey Harpster
M. Ozores-Hampton, B. Schaffer, and H. H. Bryan
The effects of amending soil with municipal soil waste (MSW) on growth, yield and heavy metal content of tomato were tested with different irrigation rates. The following MSW materials were incorporated into oolitic limestone soil: 1) Agrisoil compost (composted trash), 2) Daorganite compost (sewage sludge), 3) Eweson (composted trash and sewage sludge), and 4) no MSW (control). Two rates (high and low) were applied to the soil for each compost. There were no significant effects of irrigation rate on any of the variables tested for tomato in 1991 or 1992. Therefore, the lowest irrigation rate appeared to be adequate for optimum tomato production. Plants grown in Daorganite at the lowest rate of 8 t/ha had greater growth and yield than plants grown in the other MSW materials or the control. Agrisoil and Eweson composts did not increase growth or yield, which may have been due to suboptimal application rates of these materials. There were no differences in the concentration of heavy metals in fruit or leaves among MSW materials or rates. MSW rate generally had no effect on root heavy metal concentration, except for Eweson where the high rate resulted in a higher root zinc concentration than the low rate. There were signifant differences in root concentrations of lead, zinc, and copper among MSW materials. Leaf concentrations of all heavy metals tested were within normal ranges for tomato.
Francis R. Gouin
Compost varies according to content, comporting procedures, age, storage conditions and particle size. Compost made mostly from wood products will have a much lower nutrient and soluble salt concentration than one made from leaves, grass clippings, sewage sludge, manures or food processing waste. Compost from efficiently managed systems optimizing microbial activity will tend to have higher soluble salt levels than compost from piles that are neglected and/or undisturbed.
Regardless of which organic materials used in making compost it will have a pH between 6.2 and 7.2 when ready for use. The effectiveness of compost as a soil amendment and in formulating potting mixes is dependent on particle sizes and soluble salt concentrations. Particles should not be recognizable and less than 2.5 cm in diameter for optimum plant response. Soluble salt concentrations of the compost will determine rates of application and fertilizer regime.
George E. Fitzpatrick and Stephen D. Verkade
Three compost products made from urban waste materials, municipal solid waste (MSW), yard trash (YT), and a co-compost made from 1 part sewage sludge and 3 parts yard trash (S-YT), were used as growing media for production of dwarf oleander (Nerium oleander L.) in 25 cm. diameter containers. In one test the composts were used as stand-alone growing media and in a second test they were blended with pine bark (PB) and sand (S) in 2 ratios: 4 compost: 5 PB: 1 S and 1 compost: 1 PB: 1 S. The S-YT co-compost produced plants with the highest biomass in both tests. Reduced growth of dwarf oleander in each test was associated with the degree to which the media compacted during the 5.5 month production period. The MSW compost compacted an average 8.5 cm. per container when used as a stand-alone medium, while the S-YT mixes compacted much less, typically < 4.0 cm.
A.J. Downer, B. Faber, U. Schuch, D. Pittenger, and R. White
Forty eight California sycamores (Platanus racemosa) were planted (5/91) from one gallon containers and mulched (8/91) with, pine bark, composted sewage sludge and wood products, fresh Eucalyptus cladocalyx chips (large 2-6cm), fresh eucalyptus chips (small <1cm), composted large eucalyptus and untreated. Mulches were applied to a depth of 10cm in a 6m2 area around each tree. Irrigations were based on soil moisture depletion and water content was measured by time domain reflectometry. Mulched trees developed more caliper, lower stomatal resistances and lower trunk temperatures. Soil moisture (top 15cm) was greater under mulched trees. Rooting was evident in the sludge, and composted eucalyptus mulches but absent in the pine bark and fresh eucalyptus mulches.
Erika N. Kocsis, Ronald F. Hooks, and James N. McCrimmon
The use of grasses native to New Mexico are preferred for revegetating Albuquerque's sewage sludge disposal site. A greenhouse study was conducted to determine the most appropriate grass species that could be used in revegetation. Nine grasses grown in soil collected at Albuquerque's sludge disposal site were compared based on germination measurements, including plant height and density. Final shoot and root weights also were taken for comparison. Plant tissue was analyzed for the accumulation of metals and salts. With 200 ml of water applied weekly, plant height was greatest in spike dropseed (Sporobolus contractus A. S. Hitchc.) at 33.86 cm; plant density was greatest in alkali sacaton (Sporobolus airoides Torr.). Results indicate the grasses that have the best potential for use in revegetation are blue grama [Bouteloua gracilis (H.B.K.) Lag. ex Griffiths], sideoats grama [Bouteloua curtipendula (Michx.) Torr.], and alkali sacaton.
Jae H. Han, George L. Good, Eric B. Nelson, and Harold M. Van Es
Composts vary in their ability to suppress disease activity when incorporated into growing media. Bioassays that enable a reliable and quick assessment of compost's ability to suppress disease activity can save time, funds and space. A bioassay using Lupinu× `Russell Hybrid' seedlings was evaluated as a short-term test for gauging the ability of three composts to suppress activity of P. cinnamomi. Colonized millet seeds were prepared via the V-8 agar method. The colonized millet seed were incorporated into the potting media at 0, 50, 100, 200, and 400 colonized millet seed/200 cc of the media used. Three composts, including composted sewage sludge, brewer's waste and cow manure, were incorporated into the media (50% sand: 50% sphagnum peat, by volume) at rates of 0%, 10%, 25%, and 50%, by volume. The media, including the inoculated millet seed, were placed in small plastic pots (7.6-cm-diameter and 6.7 cm high), after which 10 Lupine seeds were sowed in each pot. Percentage of seedling loss was determined after 43 days of observation. The composted sewage sludge and the cow manure proved suppressive at the 50% incorporation rate and the 10% and 25% rate of the latter compost. The brewer's waste compost proved ineffective in this regard; thus, research with this product was discontinued. In a greenhouse study the same inoculation and compost incorporation rates were used, but rooted cuttings of Rhododendro × PJM `Elite' were plotted into the various treatments. Suppression of disease activity by the composts was significant 2 and 4 months after initiation of treatments. Significance in disease suppression noted between these treatments decreased significantly during the fifth month of the experiment.
Joan Bradshaw and Monica Ozores-Hampton
In 1988, the Florida Legislature passed the Solid Waste Management Act that affected the solid waste disposal practices of every county in the state. With legislation directly affecting the industry, organic recyclers and Florida Department of Environmental Protection (FDEP) regulators recognized a need to establish a professional organization that could serve as a unified industry voice, and foster high standards and ethics in the business of recycling and reuse of organic materials. In December 1994, a meeting was held to discuss the formulation of a Florida organic recycling association which became known as the Florida Organics Recyclers Association (FORA). FORA's first major contribution to the industry was the development of a recycling best management practice manual for yard trash in 1996. The second major project undertaken by FORA was a food waste diversion project which sought to promote an increase in food waste recovery and reuse. In Spring 1999, FORA became the organic division of Recycling Florida Today (RFT) further unifying recycling efforts within the State of Florida. In an attempt to address mounting concerns regarding industry marketing and promotional needs, RFT/FORA developed an organic recycling facility directory for the State of Florida in Spring 2000. Most recently RFT/FORA developed an organic recycling facility operator training course outline to assist the FDEP in identifying industry training needs. From its modest beginnings in 1994, to future joint programming efforts with the University of Florida's Florida Organic Recycling Center for Excellence (FORCE), RFT/FORA continues to emerge as a viable conduit of educational information for public and private agencies relative to organic recycling in Florida.
H. H. Bryan, B. Schaffer, and M. Ozores
The effects of amending soil with processed municipal waste (PMW), and the interaction of PMW with trenching, irrigation rates, and fertilizer rates on growth, and yield of tomato plants were tested. In a series of experiments, two rates of each of the following PMWs were incorporated into calcareous limestone soil: 1) Agrisoil (processed trash), 2) Daorganite (processed sewage sludge), 3) Eweson compost (processed trash and sludge), and 4) no PMW (control). In some experiments, secondary applications of PMW were applied to the beds at either a high rate, a low rate or not applied (control). There was no effect of secondary PMW applications on growth or yield. Generally, plants grown on trenched plots had greater growth and yield than plants on non-trenched plots. Plants grown in Daorganite had greater growth and yield than plants grown in the other PMWs. Plants in Daorganite tended to have higher photosynthelic and transpiration rates than plants in the other treatments. For all treatments, plants grown at one-half the standard fertilizer rate had less growth than plants receiving higher fertilizer rates. There was no interaction between irrigation rate and PMW for photosynthesis, growth, or yield. Plants grown in Daorganite had the greatest growth and tended to have greater yields, regardless of the fertilizer or irrigation rate. Processed trash composts (Agrisoil and Eweson) did not increase growth and yield, which may have been due to suboptimal application rates of these materials. Further studies are underway incorporating higher rates of these materials into the soil.
Cerinda Loschinkohl and Michael J. Boehm
The effects of incorporation of compost to a disturbed urban soil on turfgrass establishment, growth, and rust severity were assessed in a replicated field study. A blend of two locally available composted biosolids (sewage sludge) was incorporated into a nutrient-deficient subsoil at a rate of 130 m3·ha-1, adding NO3-N, P, and K at 126, 546, and 182 kg·ha-1, respectively, to each compost-amended plot. Kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.), and a mixture of these two species were seeded into both compost-amended and nonamended plots and observed for 1 year. Turfgrass establishment estimated from visual assessments of percentage cover and growth measured by clipping yields were significantly (P < 0.05) enhanced by the incorporation of the composted biosolids. These effects were first observed and most pronounced on plots seeded with perennial ryegrass and were apparent for the duration of the study. The severity of leaf rust caused by Puccinia sp. was significantly (P < 0.05) less on perennial ryegrass seeded on the compost-amended plots. This study demonstrates the feasibility and potential benefits of amending disturbed urban soils with composted biosolids to enhance turfgrass establishment and is the first report of the suppression of a foliar turfgrass disease through the incorporation of compost into soil.