COMPARING THE CHARACTERISTICS, RISKS AND BENEFITS OF SOIL AMENDMENTS AND FERTILIZERS USED IN AGRICULTURE

Farmers today are faced with an array of products that they can use to improve the fertility of their lands. Organic soil amendments such as biosolids, Municipal Solid Waste (MSW) composts, and manures are products that can be used to supplement or replace mineral fertilizers. Many farmers are aware of the benefits that organic products offer, especially in terms of improved crop yields, increased soil fertility, reduced fertilizer costs, and their overall contribution to sustainable agriculture.Concerns have been raised, however, regarding the safety of organic soil amendments. Depending on the type of product, these can include (but are not limited to) the accumulation of metals in soils, plant uptake of land-applied metals, the contamination of groundwater and soil with organic compounds, and potential health impacts from pathogens and viruses. These questions and concerns regarding amendments must be answered, and those answers effectively communicated in order to restore (or generate) confidence in the use of organic soil amendments.Ironically, organic soil amendments have been studied exhaustively for years, and the answers to many current questions regarding their use are available. Although it is often published in academic journals and textbooks, this information is not necessarily accessible to the public. For all soil amendments, information regarding risks, benefits, advantages, and disadvantages is not readily available to those who need it. Equally critical is the lack of accessible comparative data on soil amendment and mineral fertilizer characteristics and use.Recognizing the need to provide the public – especially agricultural and other users of soil amendments – with credible, objective, accessible information, the Water Environment Research Foundation (WERF) commissioned a two-year study of soil amendments and their uses. This paper summarizes the results of that study.