Effects of Different Nitrogen Fertilizer Use Level on Yield Component and Grain Yield in Yuanyang Terrace

To study the effects of different nitrogen fertilizer use levels on local traditional and introduced rice varieties in Yuanyang terrace,the nitrogen uptake,diseased index and yield of Yuelianggu(traditional) and Chu 26(introduced) were analyzed in the different nitrogen treatments.The experimental results showed that,with the increase of nitrogenous fertilizer inputs,the yield of Yuelianggu declined,rice blast happened,nitrogen uptake efficiency and nitrogen utilization efficiency went down.The yield of treatment 2(7 500 kg/hm2 organic fertilizer) had raised 14%,10% and 11%,respectively,compared with that of treatment 1(without fertilizer),treatment 3(7 500 kg/hm2 organic fertilizer + 75 kg/ hm2 nitrogen fertilizer) and treatment 4(7 500 kg/hm2 organic fertilizer + 150 kg/ hm2 nitrogen fertilizer).Meanwhile,the Chu 26 had positive responds to the exogenous active nitrogen.The yield of treatment 4(7 500 kg/hm2 organic fertilizer + 150 kg/ hm2 nitrogen fertilizer) had raised 77%,46% and 10%,respectively,compared with that of treatment 1(without fertilizer),treatment 2(7 500 kg/hm2 organic fertilizer),and treatment 3(7 500 kg/hm2 organic fertilizer +75 kg/ hm2 nitrogen fertilizer).The nitrogen utilization efficiency became higher along with the nitrogenous fertilizer inputs increased.