Cover Crop and No Tillage Practices Enhance the Carbon Sequestration in Japan.

@Cover crops and no-tillage practices may be effective tools for ensuring sustainable agriculture and eco-system service; because these soil management strategies increase soil organic matter and improve soil biological diversities and activities in intensively managed summer field cropping system. A 5 years field research in the field science research & education center, Ibaraki University, Japan, revealed that a combined with no-tillage system with cover cropping showed significantly high crop productivities and environmental advantages compare with conventional system, because these soil managements can maintain field rice yield response, scavenge soil residual nitrogen, improve carbon sequestration and their ecological functions that can be utilized to establish an optimal nitrogen cycle due to higher population and diversity of soil fauna organism. Soil organic carbon in the top 0 to 30 cm in no till and rotary till with cover crop plots increased significantly compared with winter fallow plots. This result suggested that cover crop C accumulation in the soil would increase in short term, if it combined with no-till or rotary tilled managements, even in Andisol that shows relatively high soil organic carbon content initially, and difficult to increase soil organic carbon contents. Taking account of the offset of nitrous oxide emissions, fallow plots showed negative impact for the mitigation of green house gas (GHG), because they increased of 0.015`0.253 ton CO2 ha-1 GHG emissions in all tillage systems, however, cover cropping showed positive impact for mitigation of GHG emissions because no-till with rye, rotary till with rye and rotary and hairy vetch reduced of 0.486,0.567, and 0.255 tonCO2 ha-1.