Location: Soil and Water Management ResearchTitle: Editorial: Organic wastes in soils: Biogeochemical and Environmental Aspects) Author
Submitted to: Journal of Soil Biology and Biochemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/15/2007
Publication Date: 7/1/2007
Citation: Clapp, C.E., Hayes, M.B., Ciavatta, C. 2007. Editorial: Organic wastes in soils: Biogeochemical and Environmental Aspects. Journal of Soil Biology and Biochemistry. 6:1239-1243. Interpretive Summary: The use of by-products of vegetable, animal and human origins to restore or to increase soil fertility has been well know for over 2000 years. In Roman Empire times described how organic wastes had to be processed before their use in soil. However, since the end of World War II the use of organic wastes for land fertilization had decreased and farmers in developed countries have markedly increased the use of mineral fertilizers in place of organic fertilizers and amendments. The amounts of organic materials from municipal solid wastes, sewage sludges and wastes of agro-industrial origins have increased exponentially, and millions of tons of organic matter are landfilled or incinerated and transformed into methane, carbon dioxide, nitrogen oxides, sulphur oxides and other greenhouse gases. Scientists have stressed how the scope of organic amendments of various origins and nature in modern agriculture is to increase and/or to restore the organic matter in organically poor or depleted soils in order to maintain and/or to increase crop production and reduce soil exposure to degradation, erosion, desertification and pollution. This research will benefit environmental scientists, engineers, and consultants by showing the results of experiments using waste materials in a highly positive and productive manner.
Technical Abstract: This special issue of Soil Biology and Biochemistry presents papers from the Second General Annual Conference of European Geosciences Union, Session SSS12 Recycling of Organic Wastes in Soils: Biogeochemical and Environmental Issues, held at the Austria Center Vienna, 24-29 April 2005. Session SSS12 was initiated because of the large amounts of wastes containing different amounts of organic carbon (C) as energy from agro-industrial and municipal origins, and nutrients that are produced daily, mainly in the “developed societies.” It is becoming accepted that there should not be organic materials that are classified as wastes. For sustainable development, resources must be recycled, and that especially applies for organic materials of municipal and agro-industrial origins. Soils in many parts of the world are increasingly stressed from long-term cultivation practices, and the resulting losses of soil C are leading to inevitable degradations of soil structure, losses of soil productivity, and losses of soil by erosion. Larson et al. (1972) have shown that a soil amendment of 6 t ha-1 year-1 of stover is required to maintain the organic matter level in soil cropped annually with corn (Zea mays L.). Thus it will be important to promote the thesis that ‘there is no such thing as an organic waste,’ especially if that waste is not contaminated by heavy metals, by toxic chemicals, or by pathogens. Biomass and crop residues can be recycled into the soil with or without composting or stabilization processes of the organic C. The emphasis at the symposium on which this series is based focused on composts, water-treatment sludge, municipal solid wastes, and slurries as soil amenders. Reference was made to the competition that is likely to arise for lignocellulosic crop residues, and to the fact that there is likely to be a market connected with the biorefinery industry for straw, bagasse, and stover. Char and hydrogen products from wastes and biomass would be part of a C-negative system, and hence would have C sequestration significance. Thus the future is bright with regard to soil amendments with materials that are now considered to be wastes, or with chars from these materials.