Effects Of Types Of Controlled Released Nitrogen And Fertilization Modes On Yield,ammonia Volatilization And Characteristics Of Photosynthesis And Dry Mass Production Of Japonica Rice

Rice is the most important food crops in the world,which is a staple food crop for more than 50%of the world population.It is reported that increase of 1.2%per year of rice production will be required to meet the growing demand for food that will result from population growth and economic development in the next decade.Increasing fertilizer inputs is a direct method to increase rice yield for solving the contradiction of population and food.In recent years,more people improve Nitrogen fertilizer inputs substantially to achieve the purpose of increasing food yield..However,with the increasing of the fertilizer inputs,the utilization of nitrogen decrease significantly.However,excessive amounts and inappropriate application methods lead to low N efficiency and high fertilizer losses through leaching,runoff,denitrification,and volatilization,resulting in a series of environmental problems.There were four N fertilizer types,urea,bulk blending fertilizer,resin coated urea,sulfur-coated urea and two fertilization modes,the base-tiller nitrogen fertilizer,single fertilization.The main results are as followed:1 Effects of types of controlled released nitrogen and fertilization modes on yieldThe kinds of Controlled released nitrogen and fertilization modes had a significant influence on rice yield and yield components.Controlled released nitrogen can increase yield by increasing the number of spikes and spikelet.The yield of different types of controlled released nitrogen showed that,bulk blending fertilizer>resin coated urea>sulfur-coated urea.Grain yield of the base-tiller nitrogen fertilizer treatment BT(1,2,3)was significantly higher than single fertilization treatment S(1,2,3).Compared to CK,the yield of BT-BSRB increased by 1.0,1.1 thm-2.2 Effects of types of controlled released nitrogen and fertilization modes on Characteristics of Photosynthesis and Dry Mass ProductionThe dry matter weight of population,Leaf area index and Photosynthetic potential of different controlled released nitrogens at t growth periodhe showed that bulk blending fertilizer>resin coated urea>sulfur-coated urea,the base-tiller nitrogen fertilizer treatment BT(1,2,3)was higher than single fertilization treatment S(1,2,3).Dry matter accumulation,its proportion of distribution and crop growth rate at jointing stage showed bulk blending fertilizer>resin coated urea>sulfur-coated urea while at the maturitystage showed bulk blending fertilizer>sulfur-coated ure>resin coated urea3 Effects of types of controlled released nitrogen and fertilization modes on ammonia volatilizationThe ammonia volatilization rates from the paddy field with different kinds of Controlled released nitrogen indicated that these were affected significantly by both the type of N fertilizer and the application method used(Fig.2).The ranking of max ammonia volatilization rate in different kinds of controlled released nitrogen was urea>sulfur-coated urea>bulk blending fertilizer>resin coated urea.For the CK treatment,the ammonia volatilization rates in two years reached a maximum of 10.93 and 8.28 kg hm-2 d-1 within about 3 days after fertilization application,which are higher than other treatments.