Effect of Soil Disturbance and Crop Management on Soil Food Webs.

Knowledge of the vertical translocation of surface residues and soil following tillage operations is of great importance to a wide variety of soil ecosystems. The qualitative assessment will be necessary to evaluate the soil disturbance due to different tillage systems to the agro-ecosystem; however, information regarding the relationship between the degree of surface soil translocation (DTL) and the soil nematode community with different tillage inversion systems is not well discussed. Decreasing DTL, due to reduce tillage depth and change the tillage tools, will develop the community structure of soil nematode because minimum soil disturbance.
Our objectives for this study were to compare the effects of tillage and cover crops on soil nematode community composition and indices, and to determine whether there is a relationship between nematode community indices and the DTL. We investigated the effects of three tillage systems, i.e., moldboard plow/rotary harrow, rotary cultivation, and no-tillage, and three winter cover crop treatments (fallow, rye, and hairy vetch) and two manure applications (0 and 1 Mg ha⁻¹) on changes in DTL and soil nematode community.
This study was conducted on part of a long-term experiment site at Field Science Center, Ibaraki University, Japan from 2003 to 2015. The soil is classified as a typical Andosol. Nematode community indices, including the Channel Index, Enrichment Index, and Structure Index, based on the composition of nematode assemblages, were calculated to infer soil ecosystem condition. DTL was calculated from the vertical soil distribution changes in the concentration of radioactive cesium-137 caused by the Fukushima Daiichi nuclear power plant accident in 2011.