Study On The Effect Of Partial Replacement Of Organic Fertilizer On The Yield Formation And Related Physiological Characteristics Of Rice And Wheat

With only 7%of the world’s arable land,China has fed 22%of the world’s population.this is an outstanding achievement.However,with the acceleration of urbanization,the decrease of arable land and the continuous increase of population,the food demand and food security of Chinese people are becoming more and more serious.Jiangsu province is a major province of grain production in China.In the past decades,in order to improve the crop yield per unit area,local farmers generally adopted the high nitrogen fertilizer application method.At the same time,to save the cost of farming,farmers habitually applied tillering fertilizer instead of panicle fertilizer,these fertilization habits have brought negative effects on the environment and also reduced the nitrogen fertilizer utilization efficiency.Therefore,nowadays,to advocate green agriculture and sustainable development,this experiment strives to achieve high efficiency of fertilizer and high yield of crops by optimizing the way of fertilization of farmers.The test site is located in the experimental field of dongmei farm,nandu town,liyang city,jiangsu province.The tested rice and wheat varieties are nanjing 9108 and yangfu maier 4,respectively.The test starts in the 2017 rice season and ends the 2017 winter wheat season.The experiment is partial substitution of organic fertilizer,10 treatments are set in total,which are:No nitrogen treatment(CK),farmers used to fertilization(FFP),optimized fertilization treatment(OPT),pig manure substitute nitrogen 20%treatment based on the optimization(PMSN20%),chicken manure substitute nitrogen 20%treatment based on the optimization(ChMSN20%),cow manure substitute nitrogen 20%treatment based on the optimization(CMSN20%),pig manure increase nitrogen 20%treatment based on the optimization(PMIN20%),chicken manure increase nitrogen 20%treatment based on the optimization(ChMIN20%),cow manure increase nitrogen 20%treatment based on the optimization(CMIN20%)and pig manure substitute nitrogen 20%treatment based on the optimization nitrogen management is the same as FFP(PMSN20%Ⅱ),each processing is equipped with four repeat,a total of 40 village.In this paper,the yield and yield composition,biomass,and nitrogen utilization of rice and wheat under different fertilization treatments were studied.The main test results are as follows:1.The yield can be stabilized under the rice-wheat rotation management system in jiangsu province through the reduction of nitrogen fertilizer,optimization of nitrogen fertilizer operation and partial substitution of organic fertilizer.In the rice season,there was no significant difference in the yield of nitrogen application(240 kg/hm2)under different nitrogen application treatments after reduction compared with the customary fertilizer treatment(350 kg/hm2)by farmers.At the same time,there was no significant difference in the yield under the condition that chemical nitrogen fertilizer application amount was only 200 kg/hm2.According to the yield composition data,the number of ear and grain per ear would be increased with high nitrogen application,while the 1000-grain weight and seed setting rate of each treatment under the optimal fertilization were higher than the season rise of rice.er was there was no significant difference between the yield of each organic fertilize.2.Compared with farmers’ habits,the optimized fertilization treatment improved the agronomic utilization rate,partial productivity and nitrogen absorption utilization rate of nitrogen fertilizer,while the organic replacement treatment further improved the nitrogen fertilizer utilization rate on the basis of the optimized fertilization.The analysis of nitrogen accumulation in rice and wheat showed that the optimization of nitrogen operation and organic substitution could help improve nitrogen accumulation in the later growth stage of rice and wheat,the critical period of yield formation.3.It was found that there was a significant positive correlation between the temperature difference between panicle and leaf and the yield of rice in each period by monitoring the temperature of rice panicle and leaf from post-anther to maturity.The analysis of the change of source-sink relationship from anther to maturity of rice showed that top dressing panicle fertilizer could improve the rate of rice post anther filling.Both topdressing and organic fertilizer replacement helped maintain high levels of source activity for longer periods of time,and the effect of topdressing was more pronounced.In summary,by reducing the amount of nitrogen fertilizer,optimizing the operation of nitrogen fertilizer and substituting organic fertilizer,the utilization efficiency of nitrogen can be improved while the yield of rice and wheat can be stabilized.Optimization of nitrogen fertilization and substitution of organic fertilizer could improve and prolong the activity of rice after anthesis,the effect of optimizing nitrogen fertilizer operation was more obvious.