| As China’s population continues to rise,people’s demand for food is also increasing,and the decrease of arable land makes us have to try to improve the per unit yield of crops,at the same time,a large amount of fertilizer investment has seriously affected food security and ecological environment,but also caused low efficiency of fertilizer use,waste of resources and other phenomena.Rice and wheat are the two most important food crops in China,and the rice-wheat rotation system has become an important component of China’s agricultural structure.As the main producing area of rice and wheat in Jiangsu Province,the fertilization situation is not ideal.The large amount of nitrogen fertilizer application and low nitrogen fertilizer utilization rate do not meet the basic requirements of green agriculture and sustainable development agriculture advocated at present.Therefore,it is necessary to optimize the fertilization habit,rationally utilize nitrogen fertilizer,and realize the matching of nutrient supply with the demand of crops,so as to improve the utilization efficiency of fertilizer and achieve the purpose of green production.The experiment started from wheat season in 2019 and ended in rice season in 2020,and was carried out in the experimental field of Agricultural Science Institute in Rugao City,Jiangsu Province and the experimental field of Dongmei Farm in Qianjiawei Village,Nandu Town,Liyang City,Jiangsu Province.Six experimental treatments were designed in the experimental field of Liyang City,which were no nitrogen treatment(N0),farmers’ habitual fertilizer treatment(FFP),optimal fertilizer treatment(OPT),pig manure,chicken manure and cow manure organic fertilizer replacing 20% traditional nitrogen fertilizer treatment(OPTPM),(OPTCHM)and(OPTCM)on the basis of optimization.The nitrogen distribution of wheat and rice were 4:3:3 and 4:2:2:2,respectively.In Rugao experimental field,two nitrogen management treatments were added on the basis of OPTPM,that is,the total amount of organic fertilizer and chemical nitrogen fertilizer was the same,while the ratio of regreen fertilizer,jointing fertilizer and tillering fertilizer,jointing fertilizer and promoting flowering fertilizer in wheat was different,and the wheat season was OPTPM(7:3)and OPTPM(6:4).The rice seasons were OPTPM(4:4:2),OPTPM(6:2:2)and all organic fertilizer(100%PM).Based on the study of the effects of different fertilization treatments on the yield and yield composition of rice and wheat,crop growth and development,nitrogen nutrient absorption and utilization,fertilizer benefits and crop economic benefits in the two regions,this paper provides a theoretical basis for guiding the high yield and high efficiency of rice and wheat in the two regions of Jiangsu Province.The main research results are as follows:1.In Liyang test field,wheat and rice yield per hectare of N0 treatment were 2675 kg and 7850 kg,respectively,while FFP treatment could increase wheat and rice yield by 102% and 32%,respectively;The yields of wheat and rice under OPT were increased by 334 kg and 500 kg per hectare compared with those under conventional fertilization,and N use efficiency was improved.The yield of wheat and rice can reach or even exceed that of farmers’ conventional fertilizer treatment by using organic fertilizer instead of nitrogen treatment based on OPT.In addition,the biomass,nitrogen accumulation and harvest index of wheat and rice treated with OPT,OPTPM,OPTCHM and OPTCM were increased.2.In Rugao experimental field,the wheat and rice yields of N0 treatment were 2817 kg and 5154 kg per hectare,respectively,and the wheat and rice yields of FFP treatment were 8125 kg and 10436 kg per hectare,with an increase rate of 189% and 102%.The nitrogen application amount of wheat and rice in each treatment season was the same as that in Liyang test field.In Rugao experimental field,the wheat and rice yields under OPT treatment were slightly lower than those under FFP treatment,but the yields under OPT treatment could reach or even exceed those under FFP treatment.Among the three nitrogen management treatments,the higher the ratio of topdressing,the higher the yield of wheat and rice,the wheat yield OPTPM(7:3)However,the yield of wheat and rice treated with100%PM was 4634 kg/hm2 and 9218 kg/hm2,respectively,which was not ideal.The biomass,nitrogen accumulation,harvest index and leaf area index of wheat and rice treated with organic fertilizer were all increased.In the treatment with high topdressing ratio,each index was slightly increased,and each index of 100%PM treatment was significantly higher than that of N0 treatment,and significantly lower than that of other treatments.3.The yield of wheat in Rugao is significantly higher than that in Liyang,but the yield of rice is not significantly different between the two places.In both places,the fertilizer benefit of OPT treatment was higher than FFP treatment.From the economic point of view,the economic benefit of the same treatment of wheat in Rugao is higher than that of Liyang,the economic benefit of OPT treatment of wheat in Rugao is lower than that of FFP treatment,and the economic benefit of OPT treatment of wheat in Liyang is higher than that of FFP treatment.Due to the higher cost of organic fertilizer,the yield of different organic fertilizer treatments in wheat season was significantly lower than FFP and OPT.Due to the factors of rice variety and yield in Liyang,the economic income of rice is generally higher than that of Rugao with the same treatment,and there is no significant difference between OPT treatment,FFP treatment and different organic fertilizer nitrogen replacement treatment.But in Liyang City,the use of cow dung for nitrogen can stabilize the yield and increase efficiency,and can obtain good economic and environmental benefits. |
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