Preliminary Study On The Relationship Of Yield Formation Of Double Cropping Rice And Greenhouse Gas Emissions Under Different Cultivation Methods

In order to study on the relationship of yield formation of double cropping rice and greenhouse gas emissions under different cultivation methods, In2011, super early rice Ganxin203and late rice Wufengyou T025were used for experiments. Dry matter accumulation, nutrient uptake and greenhouse gas emissions in double cropping rice were investigated. The main results are as follows:1.In early rice and late rice, the growth rate of stems and tillers under high-yield method were higher than general traditional culture, and effective panicles per unit area under high-yield method was more than general traditional culture, but the percentage of earbearing tiller of general traditional culture was higher than high-yield processing. In early rice, most of the dry matter accumulation under high-yield method was from Spikelet differentiation stage to grain filling stage, both the dry matter accumulation and N, P2O5, K2O content under high-yield method were more than general traditional culture, N, P2O5, K2O accumulation during tilling stage to heading stage was more. In late rice, most of the dry matter yield under high-yield method was from tilling stage to grain filling stage, the dry matter yield under high-yield method was more than general traditional culture, most of N, P2O5, K2O accumulation under high-yield method was from tilling stage to grain filling stage, N, P2O5, K2O accumulation as affected under high-yield processing was more than general traditional culture, during heading stage to grain filling stage, N, P2O5, K2O accumulation become less. Leaf area index under high-yield method was higher than general traditional culture in early rice and late rice, at heading stage, leaf area index under any processing attained the highest point. Rice yield under high-yield method was more than general traditional culture in early rice and late rice, the most important factor was effective panicles per unit area.2. Both the emission flux of methane and nitrous oxide in the seedling bed with moist method is higher than dry bed seedling. The changes in the number of stems and water management were the main factor of the emission flux of methane in early rice, nitrogen application and water management were the main factor of the emission flux of nitrous oxide. The increasing of nitrogen application and intermittent irrigation could increase rice yield under high-yield method, but it increased the emission flux of methane and nitrous oxide under high-yield method. To a certain extent, straw could increase rice yield, but it also increase the emission flux of methane and nitrous oxide.