Abundance of Soil Organisms Affected by Conservation Tillage in Aarable Lands

Abstract

Abundance of soil organisms affected by conservation tillage in arable lands. Tomomi Nakamoto (Laboratory of Plant Science for Sustainable Agriculture, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku Yayoi, Tokyo 113-8657, Japan). Conservation tillage is a tillage system that reduces soil disturbance and maintains much of the soil surface covered by plant residues. Advantages of conservation tillage include soil water conservation, soil erosion control, less use of fossil fuels, and laborsaving. Additionally, conservation tillage systems can preserve soil living organisms, which have several beneficial functions in arable fields, such as nutrient cycling, soil structure preservation, and population control of undesirable organisms. This paper reviews the effects of conservation tillage on the abundance of soil organisms. Most groups of soil organisms often have greater abundance or biomass in conservation tillage systems than in conventional tillage systems. This is attributed to improved soil physical properties, such as higher water content and less temperature change, and larger amount of organic matter supply in conservation tillage systems. Reduced tillage, an intermediate form of conservation tillage between conventional tillage and no-tillage, usually gives intermediate results between the two tillage systems. However, the responses of soil organisms to conservation tillage, which greatly vary with tillage methods, residue management, and the combinations of soil, climate, and crop, are more or less unpredictable. Further studies are needed, including attempts to understand interactions between microflora, micro-, meso-, and macrofauna.