Compost Science Complete scientific data on compost process control and end product quality

CURRENT RESEARCH PROJECTS

CSU Spring, 2005, Vol. 13, No. 2, p. 88

CROP RESPONSE
Chelate-Assisted Heavy Metal Uptake By Sunflowers Grown In Composted Sludge
Investigators: M.S. Liphadzi and M.B. Kirkham, Department of Agronomy, Kansas State University, Manhattan, Kansas
Objectives: To compare heavy metal uptake by sunflowers grown in composted sludge and soil with liquid sludge, when EDTA was added to facilitate uptake of the metals. No work reports availability of

chelate-solubilized heavy metals in composted sludge compared to soil in which liquid sludge has been applied. Sunflower was chosen because under field conditions, they are deep-rooted and accumulate Cd, the heavy metal of most concern in sludge.

How Compost Amendments On Fodder Crops Affect Yield, Nitrogen Utilization And Soil Characteristics
Investigators: F. Montemurro, M. Maiorana, G. Convertini and D. Ferri, Istituto Sperimentale Agronomico, Bari, Italy
Objectives: To evaluate the effects of two organic amendments - municipal solid waste compost and olive pomace compost - compared with mineral fertilizer. To accomplish this objective, data on crop yielding response, quality, N utilization, N uptake and soil N availability were collected over a three-year experiment in two of the most important permanent fodder crops (alfalfa and cocksfoot) in southern Italy. Tracked differences in soil chemical characteristics at selected sampling dates are also investigated after the compost applications. Concerns relating to land degradation, inappropriate use of inorganic fertilizers, atmospheric pollution, soil fertility and biodiversity are rekindling global interest in organic recycling practices.

ENVIRONMENTAL IMPACT
Thermophilic Composting Of Crop Residues For Inactivation Of Tobacco Mosaic Virus (TMV)
Investigators: A.E. Ghaly, F. Alkoaik and A. Snow, Biological Engineering Dept., Dalhousie University, Halifax, Nova Scotia, Canada; R. Singh, Potato Research Center, Fredericton, New Brunswick, Canada
Objectives: To evaluate effectiveness of a controlled thermophilic composting process of infected tomato plant residues in eradicating TMV. Researchers study the impact of a bioreactor, in which a homogenous distribution of temperature is maintained by adding bioavailable carbon and low mixing.

MATERIALS AND METHODS
Chemical Characterization Of Vermicompost From Waste Streams In Mexico
Investigators: R.S. Hernández, V.M. Ordaz Chaparro, G.S. Benedicto Valdes, IRENAT, Mexico, D.J. Palma Lopez, Campus Tabasco, Tabasco, Mexico; and J. Sánchez Bolon, Instit. Tecnológico Agropecuario, Tabasco, Mexico
Objectives: To evaluate the survival of earthworms in different waste streams and the capacity of the earthworms to produce vermicompost. Effects of high C:N ratios were studied as well as changes in chemical characteristics. Materials tested included filter cake, manure, sugarcane bagasse, cocoa husk.

Effect Of Inoculum Size On Composting Greenhouse Tomato Plant Trimmings
Investigators: F. Alkoaik and A.E. Ghaly, Biological Engineering Department, Dalhousie University, Halifax, Nova Scotia, Canada
Objectives: To investigate the effect of inoculum (composted municipal solid waste) size on the lag period, temperature rise, maximum temperature and duration of high temperature during the composting process of tomato trimmings. The researchers note that since wood shavings, which comprised 65 percent of the total mixture, contain no bioavailable carbon, another bulking agent should be considered.

Vermicomposting As An Animal Waste Management Component
Investigators: John J. Classen and Rhonda Sherman, Biological and Agricultural Engineering Department, North Carolina State University, Raleigh, North Carolina; J. Mark Rice, National Center for Manure and Animal Waste Management, North Carolina State University, Raleigh, North Carolina
Objectives: To determine the effect on growth and on nutrients in runoff of vermicompost made from separated swine solids applied to turnips in four growing seasons. A goal of modern animal waste management systems is to convert manure to a form that reduces odors and pathogens while preserving nutrients in a way that can be moved off the farm and out of sensitive watersheds. The goal of this project was to demonstrate the usefulness of vermicompost in an agricultural setting. If crop growth can be enhanced without increasing nitrogen or phosphorus runoff pollution, then the vermicompost product can be evaluated further for economic efficiency. In the same manner, if nitrogen or phosphorus pollution can be decreased without reducing crop growth or quality, the product is also in a position for further evaluation.