Effect Of Nitrogen Amount On Yield,Qualityand Lodging Of Japonica Rice Under Dill Seeding

In order to explore the effect of nitrogen amount on growth,yield and quality of different japonica rice cultivars under drill seeding,the japonica rice cultivars Shendao 528（erect panicle type）,Shendao 305（semi-erect panicle type）and Shendao 529（semi-erect panicle type）are used as the entries to study the effect of four different nitrogen amount under drill seeding on yield and its components,quality traits,nitrogen uptake and use efficiency,photosynthetic characteristic,matter accumulation and population growth,and Lodging Resistance.1.Effect of nitrogen amount on yield and its components of different Japonica Rice cultivars under drill seeding.After nitrogen application,the yield of three nitrogen amount increased significantly by more than 50%,the yield of three cultivars increased first and then decreased with increasing of nitrogen amount,and the yields of three cultivars were the highest at 150kg·hm^-22 level,and are significantly higher than others.Spikelets per panicle increased with increasing of nitrogen amount,seed setting rate and 1000-seed-weight decreased with increasing of nitrogen amount,effective panicle per unit area increased significantly after nitrogen application,being consistent with yield performance,and were the highest at 150kg·hm^-2level.2.Effect of nitrogen amount on quality traits of different Japonica Rice cultivars under drill seeding.After nitrogen amountn brown rice rate,milled rice rate and head rice rate all increased with increasing of nitrogen amount and processing quality of Japonica rice under drill seeding had improved.Chalkiness rate and chalkiness degree all increased with increasing of nitrogen amount rate and are the highest at 180kg·hm^-22 level and grain quality of japonica rice under drill seeding decreased apparently with the increasing of nitrogen amount.PKV and DBV all decreased with increasing of nitrogen amount,so eating quality had declined.Pr content had increased with increasing of nitrogen amount,so nutritional quality had improved.3.Effects of nitrogen amount on nitrogen absorption and utilization efficiency of different Japonica Rice cultivars under drill seeding.Nitrogen amount affected the nitrogen absorption and utilization efficiency of Japonica rice under drill seeding.The total nitrogen accumulation tended to increase after applying nitrogen fertilizer,and reached the maximum value at 150 kg/hm²（N3）,and excess nitrogen amount led to the decline of total nitrogen accumulation;The nitrogen use efficiency of Shendao 529 nitrogen amount area is significantly higher than that of nitrogen-free area.The nitrogen utilization efficiency of the other two varieties is less affected by nitrogen amount rate,and with the increasing of nitrogen application the nitrogen utilization efficiency also increased gradually;Nitrogen agronomic efficiency is consistent with recovery efficiency of nitrogen fertilizer and are greatly affected by high nitrogen application rate.Excess nitrogen amount（180 kg/hm²）led to a significant decline of nitrogen agronomic efficiency and recovery efficiency of nitrogen fertilizer;Partial factor productivity decreased significantly with increasing nitrogen amount.4.Effect of nitrogen amount on photosynthetic characteristic and population growth of different Japonica Rice cultivars under drill seeding.Photosynthetic characteristic is significantly affected by the level of nitrogen amount.After nitrogen amount the photosynthetic rate of three cultivars increased significantly,and the maximum of three cultivars is all at 150 kg/hm²（N3）.The photosynthetic rate of flag leaf is higher than that of the second leaf,and it increased first and then decreased with the increasing of nitrogen amount.Leaf area index of three cultivars increased first and then decreased with the increasing of nitrogen amount,and the maximum of three cultivars is all at150 kg/hm²（N3）.Phase accumulation is consistent with photosynthetic rate and leaf area index.Phase accumulation and population growth rate are also the highest at the level of nitrogen amount with the highest photosynthetic rate and leaf area index.5.Effect of amount of nitrogen amount on lodging traits of different Japonica Rice cultivars under drill seeding.After nitrogen amount fertilizer,the internode length increased and the cross-sectional area decreased;the breaking resistance decreased significantly and the lodging index increased significantly with the increase of nitrogen amount.The resistance of erect panicle type cultivar Shendao 528 is affected by panicle type factor slightly,and the neck-panicle angle of Shendao 305 and Shendao 529 increased significantly with the increase of nitrogen amount.Therefore,increasing the breaking resistance of stem is an important way to improve the lodging resistance of rice,and the yield of drill seeding japonica rice is improved by selecting varieties with high breaking resistance and increasing the effective panicle per unit area to increase the yield with the proper nitrogen amount.