Changes of Soil Physical and Chemical Properties Using Green Manure Hairy Vetch (Vicia villosa) Under Rice-Based Cropping.

     The use of green manure crops is considered as a good management practice for soil fertility and quality improvement. These experiments were conducted to improve the soil environment under rice based cropping system at paddy soil (fine loamy, mixed, nonacid, mesic, family of Aeric Fluventic Haplaquepts) in National Institute of Crop Science (NICS), Rural Development Administration, Korea in 2007/2008 to 2008/2009. Treatments consisted of conventional practice (no green manure), partial tillage hairy vetch (PTHV), and no tillage hairy vetch (NTHV). Hairy vetch was broadcasted before rice harvest at NTHV plot. After rice harvest, rice straw was mulched. After green manure application, rice (cv. Pungmibyeo) cultivation was practiced by no chemical fertilization. The chemical fertilizers of 90 kg N, 45 kg P₂O₅, and 57 K₂O per ha were applied at conventional plots. After rice cultivation using green manure hairy vetch, the soil bulk density and porosity ratio were improved by partial tillage and no tillage cultivation of hairy vetch. Soil carbon, organic matter, did not increase during this experiment. The production of green manure and rice yield had no difference between PTHV and NTHV plot. Soil bulk density, porosity ratio and soil carbon of PTHV and NTHV had no differences. However, soil glomalin concentration and water sable aggregates increased compared with conventional practice after rice harvesting. Therefore, we recommend that soil quality should be improved by green manure cultivation under rice based cropping system.