Effects Of Nitrogen Application Patterns On Yield, Quality And Nitrogen Utilization Of Different Rice Varieties

Japonica rice is widely cultivated in northeastern China because of its superior food quality and stable grain yield produced.Nitrogen is an indispensable and important element in rice growth,but excessive application of nitrogen fertilizer causes many problems.Nitrogen fertilizer optimization model is one of the important measures to improve rice yield and nitrogen fertilizer utilization.This study is based on a nitrogen fertilizer management model,using field trials,setting different fertilization periods and nitrogen levels,and other experimental treatments to discuss the effects of nitrogen application patterns on rice growth and development characteristics,yield,quality,and nitrogen absorption and utilization in this area.The specific experimental desigin is optimization experiment of nitrogen application methods,field experiment was carried out in Shenyang,and the japonica type super rice Shennong 265?SN265?,curved panicle japonica rice Toyonishiki,hybrid japonica rice Liaoyou5206?LY5206?was used as the test material,no nitrogen application treatment?N0?,conventional nitrogen application treatments(N1,36% nitrogen as base fertilizer,24% nitrogen as tiller fertilizer and 40% nitrogen for panicle fertilizer,total nitrogen application rate is 225 kg hm^-2).And on the basis of the conventional nitrogen application mode N1?apply 5 leaves of tiller fertilizer?,the manure was moved to the 9-leaf stage after the fertilization period and two different manure fertilizer treatments were set?low 20% amount of fertilizer,normal amount of fertilizer?.The main research results are as follows.1.The field test results of two years showed that there were significant differences in population growth and development of the erect panicle type,curved panicle type,and hybrid japonica plant populations under different nitrogen fertilization strategies.In the fertilization mode?conventional fertilization mode?in which fertilization was applied 7 days after rice transplanting,the dry matter accumulation,leaf area index,photosynthetic potential,and population growth rate of the organs in the tillering stage?9 leaves?were similar to Compared with plants under nitrogen optimized treatment mode,no significant difference was found.After nitrogen fertilization was applied at the tillering stage,the dry matter accumulation,leaf area index,photosynthetic potential and population growth rate of rice organs were significantly higher than those of conventional fertilization.The treatment that shifted back after manure and reduced the nitrogen by 20% performed the most prominently in the nitrogen optimization treatment.2.There were also significant differences in nitrogen uptake and utilization among erect panicle japonica rice varieties,curved panicle japonica rice varieties and hybrid japonica rice plants under different nitrogen fertilizer strategies.At the vegetative growth stage,the nitrogen accumulation amount,nitrogen metabolism enzymes NR and GS activities of rice plants under conventional fertilization mode were not significantly different from those of the optimized nitrogen treatment.After nitrogen fertilization was applied at the tillering stage,the nitrogen accumulation amount,nitrogen metabolism enzymes NR and GS activity of rice plants were significantly higher than those of conventional fertilization mode.The treatment that shifted back after manure and reduced the nitrogen by 20% performed the most prominently in the nitrogen optimization treatment.3.Under different nitrogen fertilizer strategies,by delaying the fertilization time of nitrogen fertilizer at the tillering stage and simultaneously reducing the amount of manure application by 20%,the yield components of the three rice varieties were more balanced,the number of ears was higher,and the seed setting rate was relatively more High,it is also outstanding in terms of output.The yield of rice optimized by N2 treatment of Shennong 265 increased by 9.2% and 14.4% compared with N1 treatment in two years;the yield of rice optimized by N2 treatment of N2 increased by 10.0% and 14.0% compared with N1 treatment in two years.;The rice yield of nitrogen optimized treatment N2 treated by Liaoyou 5206 increased by 12.0% and 11.7% over N1 treatment in two years,respectively.4.There were also significant differences in rice quality among upland panicle japonica rice,curved panicle japonica rice and hybrid japonica rice under different nitrogen fertilizer strategies.The application of nitrogen fertilizer in a certain range increased the brown rice rate and polished rice rate;in addition,the chalky grain rate and chalkiness increased significantly,but the aspect ratio of rice did not change significantly;the protein content showed an increasing trend with the increase of nitrogen application rate;but Grain amylose content was not significantly changed.With the application of nitrogen fertilizer,the highest viscosity,hot slurry viscosity,and disintegration value all showed a downward trend,while the cold glue viscosity,recovery value,and reduction value all showed an upward trend.There was no significant change in the peak time and gelatinization temperature.