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

CURRENT RESEARCH PROJECTS

Compost Science & Utilization, (2007), Vol. 15, No. 3, 140

Crop Response
Toxicity of immature and mature poultry manure

Investigators: M. Mar Delgado, José V. Martin, Rosario Miralles de Imperial, Cristina León-Cófreces, M.Cruz. García, Environmental Department, INIA, Madrid, Spain; Agricultural Technological Institute of Castilla and Leon, Finca Zamadueñas, Castilla and Leon, Spain

Objectives: To determine the toxicity of different immature and mature poultry manure types (laying hens and broilers). The biological cress (Lepidium sativum, L.) germination method was utilized to

determine those residues. One of the important factors affecting the successful use of poultry manure for agriculture purposes is compost stability /maturity. Applications of unstable or immature compost may cause slow plant growth and damage crops inducing phytotoxicity to plants due to insufficient biodegradation of organic matter. There is a need to test a biological method to evaluate the degree of maturity of the material.

Environmental Impact
Short-term effects of hazelnut husk compost and organic amendments applications on a clay loam soil

Investigators: Damla Bender Özenç and Nedim Özenç, Agricultural Faculty, Department of Soil Science, Ordu, Turkey; Giresun Hazelnut Research Institute, Giresun, Turkey

Objectives: To evaluate the short-term effects of using hazelnut husk compost, and other materials such as peat, farmyard manure and chicken manure, as soil amendments at different rates on selected soil physical properties of a clay loam soil; And to determine how often hazelnut husk compost should be reapplied. Laboratory and greenhouse treatments have shown that hazelnut husk compost can be applied as a material for plant growth and to positively affect soil properties, but no studies could be found supporting land application of hazelnut husk compost as soil amendment.

Leaching behavior of lead, zinc, cadmium, cobalt, copper, chromium and nickel from biosolids-amended sandy soils

Investigators: Yuangen Yang, Zhenli He, Peter J. Stoffella, Donald A. Graetz, Xiaoe Yang, and Douglas J. Banks, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China; University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, Florida; Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Natural Resources and Environmental Sciences, Zhejiang University, Hangzhou, China; University of Florida, Department of Soil and Water Science, Gainesville, Florida

Objectives: To evaluate the effects of biosolids rate on leaching losses of heavy metals from sandy soils with contrasting properties. This information is needed for the development of best management practices for agriculture in sandy soil regions, since few studies have been conducted on sandy soils to ascertain the leaching potential of heavy metals applied in organic amendment, as affected by soil properties.

Materials and Methods
Choosing a mixture ratio for the on-farm production of Arbuscular mycorrihizal fungus inoculum in mixtures of compost and vermiculite

Investigators: David D. Douds, Jr. and Gerald Nagahashi, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania; Carolyn Reider and Paul R. Hepperly, The Rodale Institute, Kutztown, Pennsylvania

Objectives: To produce regression equations to predict optimal mixture ratios using routine measures of compost nutrient analyses as independent variables, based on experiments conducted over two years using a complete factorial design with three composts, four mixture ratios and three Arbuscular mycorrihizal (AM) fungi. AM fungi are potentially important tools in sustainable agriculture due to their roles in crop nutrient uptake, disease resistance, and water relations in stabilizing soil aggregates. Simple equations were developed to predict optimal fraction of compost in the mixture for each of the three AM fungi studied (Glomus intraradices, Glomus mosseae, and Gigaspora rosea). Percent N, P, and K and N:P ratio were the significant independent variables. The authors suggest that these equations allow farmers to choose a mixture ratio for on-farm propagation of AM fungi knowing only the nutrient analysis of the compost to be used.

Effect of maturation of grease-trap compost on plant growth

Investigators: Kevin Wilkinson, David Beardsell, Craig Hudson, Emily Tee and Vanessa Hood, Department of Primary Industries, Victoria, Australia; CR Hudson and Associates, Surrey Hills, Victoria, Australia

Objectives: To investigate the effect of maturation of grease trap compost (GTC) on growth of radish and alyssum in glasshouse phytotoxicity trials and lettuce grown on a commercial vegetable farm. Although it is known that immature composts can depress plant growth, few studies have quantified this effect in real-world scenarios with field-grown vegetable crops.