compost and cover crops are integral components in organic management systems. Compost is applied to promote soil biological activity ( Raviv, 2005 ), suppress disease ( Stone et al., 2003 ), increase soil organic C ( Jackson et al., 2004 ) and supply
Danielle D. Treadwell, Nancy G. Creamer, Greg D. Hoyt, and Jonathan R. Schultheis
Zhengli Zhai, David L. Ehret, Tom Forge, Tom Helmer, Wei Lin, Martine Dorais, and Athanasios P. Papadopoulos
and compost products in the nursery industry, some of which could be applied to organic production settings. Amending soil or potting media with some organic wastes can improve soil physical properties with increased porosity and waterholding capacity
Panayiotis A. Nektarios, Ioannis Amountzias, Iro Kokkinou, and Nikolaos Ntoulas
a substrate must consist primarily of inorganic materials, whereas large quantities of composted or other organic substances should be avoided as a result of the substrate subsidence that results from their decomposition. Rowe et al. (2006
Ronnie W. Schnell, Donald M. Vietor, Richard H. White, Tony L. Provin, and Clyde L. Munster
soluble nutrients and organic C to soil ( Johnson et al., 2006a ), a high C- to-N ratio of composted municipal biosolids (CMB) reportedly limited turfgrass growth rate and development of dark green color ( Linde and Hepner, 2005 ). If the balance of N
Allen V. Barker
Activators are suggested as adjuvants to accelerate rates of composting of plant residues. Three activators, two microbial preparations and one enzyme-based material, were assessed. The feedstock for composting was a 1:1 volumetric ratio of vegetative food wastes and autumn leaves from broadleaf trees. Composting was conducted in 0.35-m3, covered, plastic bins. In one experiment, the bins were filled to capacity twice, once at treatment initiation and at 1 week later. Treatments included no activator, an addition of each microbial preparation individually, addition of the enzyme-based activator individually, and additions of one of the microbial preparations and the enzyme-based activator in combination. The individual applications were at full-strength according to recommendations on the labels, and the combinations were at full-strength or at half-strength according to the recommendations. Piles in the bins were turned weekly, and activators were added weekly or only once according to the manufacturers' recommendations. Composting proceeded for 60 days. In a second experiment, the same protocols were followed with the modification that feedstock was added to each bin weekly for 60 days, followed by a 30-day curing period. Temperatures of the compost were recorded weekly. Piles were moistened weekly after turning. None of the activators accelerated the rate of composting relative to the rate with no activators. Rate of composting was evaluated by comparison of the weekly temperatures of the piles, the volume of compost produced, and the texture of the compost. Tomato (Lycopersicon esculentum Mill.) plants grew equally well in composts from each of the treatments. The conclusion was that compost activators did not modify the process or quality of compost produced from food and tree-leaf residues.
Kimberly K. Moore
The ornamental horticulture industry uses a variety of materials as ingredients in growing substrates for many ornamental plants. There are many attributes that make growing substrates effective, including good aeration and drainage, availability at an acceptable price, and chemical attributes conducive for plant growth. In recent years there has been a trend in which more traditional organic components, such as Canadian sphagnum peat, have been partially replaced by an increasing array of waste-product compost. Plant response to increasing quantities of compost in the potting mix, and to different types of compost are variable. This paper reviews some important issues in the utilization of urban waste compost products.
R.C. Funt and A.K. Hummell
Compost increases nutrient availability, cation exchange capacity, and micronutrients in the soil. In urban areas, yard waste consisting of grass clippings, leaves, and woody materials can be composted. The purpose of this study was to compare the effects of soil-composted municipal sludge and soil-composted yard waste mixtures on strawberry plants grown in the greenhouse. Earliglow strawberry plants were planted in pots containing a soil mix of 0%, 10%, 20%, or 40% by volume of composted municipal sludge or composted yard waste. Plants were grown in the greenhouse with supplemental lighting. Soil-compost mixes having greater the 90 mhos of soluble salts were detrimental to the plants; plant survival was reduced by 80% in the 40% composted sludge–soil mix within 2 weeks after transplanting. Plants survived and grew in all other treatments. Composted yard waste at 20% to 40% by volume increased leaf K and B, but decreased P, Ca, and Mg.
Monica Ozores-Hampton, Thomas A. Obreza, and George Hochmuth
Large volumes of compost produced from waste materials like yard trimmings, household trash (municipal solid waste), or biosolids (wastewater sludge) will likely become available for use by the Florida vegetable industry in the future. Using compost to produce vegetables has the potential to increase water and fertilizer conservation and reduce leaching from inorganic fertilizers in Florida's sandy soils. Compost quality for vegetable production systems should be based on soluble salts, phytotoxic compounds, C:N ratio, plant nutrients, trace metals, weed seeds, odor, moisture, pH, water-holding capacity, bulk density, cation exchange capacity, and particle size. In Florida, immature compost contained phytotoxic compounds that were harmful to crop germination and growth. Amending soil with mature composted waste materials has been reported to increase the growth and yields of vegetable crops grown in Florida. However, a beneficial response does not always occur, and the magnitude of the response is often not predictable.
Robert F. Bevacqua and Valerie J. Mellano
Compost made from sewage sludge (40% by volume) and chipped trimmings of Eucalyptus trees (60%) was evaluated as a soil amendment for the field. production of onion (Allium cepa cv. Spanish Sweet Utah), lettuce (Lactuca sativa cv. Black Seeded Simpson), snapdragon (Antirrhinum majus cv. Sonnet Yellow), and turfgrass (Festuca arundinacea cv. Marathon). Turf shows a strong reponse to preplant compost applications and is relatively tolerant of the buildup of soluble salts that can occur with compost applications. Also since it is not a food crop the possible uptake of heavy metals is not a major concern. These results indicate the amending of soil for the planting of turf is a likely commercial use of the compost. The authors are presently evaluating the use of the compost as a top dressing on turf plantings.
Michele Krucker, Rita L. Hummel, and Craig Cogger
reduces solid waste production and the subsequent need for disposal. Alternative components include various composted materials ( Carlile, 2008 ; Corti et al., 1998 ) using feedstocks such as yard debris and pruning waste, animal manures, biosolids