Supplying rate of nitrogen at HV was 172.8 kg ha-1, HV/B was 64.3 kg ha-1 and B was 38.6 kg ha-1. The Rice yield was 7.05 ton ha- I when the nitrogen supply was the largest with HV and 5.42 ton ha- I was produced on HV/B. The chemical characteristics of soil have lower pH and exchangeable cations(Ca and Mg) at B, HV and HV/B, rather than at CF because green manure was applied at the former step. However, the physical characteristics of the soil and the porosity showed different tendency which was that it was better at the green manure crops than CF. Nitrogen nutrient balance was showed the most balanced at CF and field of application of green manure crops were required the appropriate management if future crops would be cultivated because nitrogen nutrient could be exhausted or accumulated. Introduction

Chinese milkvetch(CM) has been cultivated as green manure source for environment friendly farming in southern area. This experiment was conducted to produce good quality rice through studying the changes of yield, quality and leaf colors as affected by the amount of CM biomass retuned to paddy field. We growed rice, transplanted in June 10 with cultivar dongjinilho, in four different plots retuned green manure with 0, 1.5, 3.0, and 4.5 ㎏ m-2 CM biomass in May 30. Nitrogen amounts were 5.5g by 1.5㎏CM biomass, 11.1g by 3.0㎏, and 16.6g by 4.5㎏ in late May. There were no different SPAD values among treatments in 10 days after transplanting. However, the more the CM biomass from 20 days after transplanting, the higher the SPAD values were. the plot of CM biomass to 3.0 ㎏ m-2 had same heading date but the plot of 4.5 ㎏ m-2 was one day late heading date as compared with the others. There were no different plant height, number of panicle, panicle length, number of leaf and ripening ratio among the CM biomass amounts. The higher the CM biomass amount, the more likely the plant was lodge. the plot retuned CM fresh biomass 1.5 ㎏ m-2 showed the higher rice yield than the plot retuned 3.0 and 4.5 ㎏ m-2 in 2006, but all plots had similar rice yields in 2007. There was no different whiteness of rice among all treatments . The more the CM biomass amount retuned to plot, the higher the protein content of rice.