The Study On Nitrogen Sensitivity Of Different Years Rice Varieties

In order to explore the rice nitrogen sensitivity among different years, differentvarieties and different fertilizing amount, One field experiment for different yearsmiddle,late japonica rice nitrogen sensitivity was carried out in2011, Another in-depthstudy of different japonica rice and indica rice nitrogen sensitivity was carried out In2012.Main research conclusion is as follows:(1)With the advance of the years, yield and Agronomic N use efficiency(ANUE)ofmiddle and late rice varieties are on the increase.The dry matter biomass and the number ofeffective panicles tend to decrease.With the increase in the amount of nitrogen，yield andthe dry matter biomass of middle and late rice varieties are on the increase,ANUE tends todecrease.With the advance of the years, yield and ANUE of middle and late rice varietiesare on the increase, the dry matter biomass and the number of effective panicles tend todecrease. With the increase in the amount of nitrogen，yield and the dry matter biomass ofmiddle and late rice varieties are on the increase,ANUE tends to decrease.(2)There was a parabolic relationship between the amount of nitrogen and yield、thedry matter biomass、The amount of accumulated nitrogen, ANUE of middle and late ricetends to decrease, the SPAD value statistically significant increases with increasing amountof nitrogen.There have some varieties of middle and late rice:Wuyujing5、 Zaofeng9、Shuangchao25、Guichao2、Wujing13、Bing91-17、Sudao1、Zhenguiai、Zhaiyeqing. Theiryield statistically significant increases with increasing amount of nitrogen and Higher thenother varieties under same fertilizer levelThe number of effective panicles increases with increasing amount of nitrogen.Nitrogen fertilizer could significantly increase grains per panicle.However, overdosenitrogen fertilizer instead lead to a decline in the number of grains per panicle and seedsetting rate.The dry matter biomass of Hexi41、Wuyujing5、Chujing24、Xianxiaozhan、Luke3、Shuangchao25、Sudao1、Bing91-17、Huxuan19、Shuangzhuzhan、 Zhechang3are Higherthen other varieties.The amount of accumulated nitrogen of Chujing24、 Wuyujing5、 Hexi41、Xianxiaozhan、Shuangchao25、Huxuan19、Bing91-17、Wujing13、Shuangzhuzhan、Zhaiyeqing are Higher then other varieties.Agronomic N use efficiency is Higher then other varieties for Zhendao99、 Wuyujing5、Hexi41、Xianxiaozhan、Shuangchao25、Luke3、Bing91-17、Wujing13、Sudao1、Zhenguiai、Zhaiyeqing8.The SPAD value is Higher then other varieties for Zhendao99、Zaofeng9、Tainan6、Zhenzhuai11、Wujing13、Huxuan19、Wunongzao、Xiangwanxian1After in-depth discussions on the rice nitrogen sensitivity, Results show that highnitrogen sensitivity of rice varieties there yield, the dry matter biomass and the amount ofaccumulated nitrogen were significantly higher then other varieties. Agronomic N useefficiency is high too, but Agronomic N use efficiency is only necessary condition.