Agroecological Study of Sustainable Crop Production Systems -Living Mulch and Soil Biota-

Research Project , Research Report 2003

Tomomi NAKAMOTO Graduate School of Agricultural and Life Sciences, The University of Tokyo
Mariko TSUKAMOTO Graduate School of Agricultural and Life Sciences, The University of Tokyo(Research Partners)
Peter STAMP Institute of Plant Sciences, Swiss Federal Institute of Technology, Switzerland

Abstract

The benefits of living mulches include not only soil erosion control and less use of herbicides but also preservation of soil organisms, which may result in improved soil productivity and sustainability. The effect of the use of living mulch of white clover (Trifolium repens L.) on the abundance of various components of the soil detritus food web was studied in maize cropping on Andosols for 2 years. Microbial substrate-induced respiration (SIR) and population densities of protozoa (flagellates, naked amoebae, ciliates), nematodes, and microarthropods (mites, collembolans), which were measured at about 1-month intervals in both years, were increased by the use of living mulch. The communities of soil organisms under the white clover living mulch systems was at a more mature stage of succession, and characterized by the enhancement of fungal pathway of organic matter decomposition and the high population density of higher trophic groups, such as mesostigmatid mites and ciliates. Higher litter decomposition rate under living mulch plots compared with no-living mulch plots, determined by a litterbag method, suggested that the function of the detritus food web was enhanced under the living mulch system. On the other hand, inorganic fertilization increased only nematodes and mesostigmatid mites in mid-summer, which was possibly attributed to better maize growth resulted from inorganic fertilization, and had neither positive nor adverse effect on other soil biological groups. It is suggested that the use of white clover living mulch in maize cropping may preserve soil organisms without reducing productions, if adequately fertilized.

Keywords:

Living mulch; Soil biota; Soil ecology