Optimization Of Organic-Inorganic Compounding Based On Triple Relationship Between Nitrogen Input Level,Soil Nitrogen Content And Crop Yield

Reasonable fertilization is an important measure to ensure the high yield of crops and avoid the disadvantages of non-point source pollution.This study used 35 representative locations in China as research areas.Used long-term localized fertilization test results,to explore the effects of different nitrogen application rates and fertilization modes on crop yield and nitrogen used efficiency in different regions,and the effect of different nitrogen application rates and fertilizer ratio on crop yield.In order to achieve the reduction of chemical fertilizers,a reasonable organic and inorganic compounding scheme is proposed to provide a reference basis.The main conclusions are as follows:1.There is a parabolic trend between crop yield and fertilization in different regions.In some areas,the crop yield increased with the increase of nitrogen application rate;the highest crop yields in different regions are commonly found in organic and inorganic compounding treatments;the highest crop yield in some areas occurred in the treatment of purified fertilizer.2.The utilization rate of nitrogen fertilizer in different regions showed a downward trend with the increase of nitrogen application rate.In some areas,the utilization rate of nitrogen fertilizer increased with the increase of nitrogen application rate under the treatment of pure organic fertilizer;the highest value of nitrogen fertilizer utilization in different regions is commonly found in the treatment of purified fertilizer and organic and inorganic fertilizer,the highest value of nitrogen fertilizer utilization in some areas appeared in the treatment of pure organic fertilizer.3.There was a significant difference in crop yields between treatments in different regions.It is generally manifested that there is no significant difference in crop yield between the treatment of organic and inorganic fertilizers and the treatment of purified fertilizers,however,they are higher than pure organic fertilizer treatment and no fertilization treatment.There was no significant difference in crop yield between the treatment of purified fertilizer,the treatment of organic and inorganic fertilizers and the treatment of pure organic fertilizer,but significantly higher than no fertilization treatment.There was no significant difference in crop yield between the three areas without fertilization treatment,purified fertilizer treatment and pure organic fertilizer treatment,but significantly lower than organic and inorganicapplication.4.There was a significant difference in crop nitrogen use efficiency between different treatments in different regions.It is generally indicated that there is no significant difference in nitrogen utilization rate between crops treated with organic and inorganic fertilizers and pure organic fertilizers,but it is significantly higher than that of purified fertilizers.There was no significant difference in nitrogen utilization rate between the treated with pure fertilizer and pure organic fertilizer,but it was significantly lower than that of organic and inorganic fertilizer.In other areas,there was no significant difference in crop nitrogen use efficiency between different treatments.5.When the proportion of nitrogen fertilizer in different areas is fixed in different regions,the crop yield basically increases first and then decreases.After the crop nitrogen application rate exceeds a certain amount,the crop yield begins to decline sharply.Comprehensive analysis of the effects of nitrogen application rate and fertilizer replacement ratio on crop yields shows that the use of organic fertilizers has a considerable ability to replace fertilizers,and it does not significantly reduce crop yields,even higher than that of purified fertilizers,in order to avoid a significant reduction in production,it is necessary to meet the demand for total nitrogen application when considering the improvement of the organic fertilizer replacement rate.