Analysis The Gap And Formation Mechanism Of Yield And Resources Use Efficiency Level Of Summer Maize Under Different Yield Levels

In this experiment,DH605 was used as the test variety.It was tested in Zhangyao Village,Erlang Township,Xiping County,Zhumadian City,Henan Province and Juqiao Town,Qibin District,Hebi City,a total of four cultivation patterns :SH-super high yield level;HH-high yield high efficiency level,FP-farmer’s production level,N0P0K0-level of without fertilizer application.This study to reveal the Huang-Huai-Hai summer maize in southern area provides the theoretical foundation,high-yield cultivation level,by investgation on farmers’ peoduction and different yield management level test,evaluation of main control factors of restricting yield gap,to study the potential yield,gap of yield and resource utilization efficiency of summer maize under different yield levels,photosynthetic characteristics,dry matter accumulation and distribution,nutrient use efficiency,the influence of the main research results of the following aspects.The main factors limiting the yield of summer maize in the southern part of Huang-Huai-Hai region were cultivation technology factors,followed by abiotic factors,biological factors and social and economic factors.The main problems are one more and three less in production,more natural disasters,less good and widely suitable varieties,less efficient cultivation techniques and less high-quality farmland.Under the same natural conditions,the super high yield level and high yield high efficiency level can increase the actual yield by 2.29 t/hm2 and 1.49 t/hm2,respectively,and improve the radiation and heat use efficiency by 20.30%,20.22%and 12.95%,12.86%,compared with the farmer level.The potential yield realization rate of super high yield level and high yield and high efficiency level was significantly increased,the yield difference between potential yield and measured yield was significantly reduced,and the rules of radiation and heat use efficiency were consistent with the yield.The results showed that the super high yield level and high yield and high efficiency level had positive significance for realizing crop high yield and reducing yield and efficiency.Under the condition of increasing the amount of irrigation,the super high yield level and high yield and high efficiency level were significantly higher than that of the farmer level,but the irrigation efficiency decreased on the contrary.Nitrogen fertilizer had the greatest effect on the grain yield of summer maize,followed by phosphorus and potassium fertilizer.The utilization efficiency of super high yield and high yield could be improved by reducing the application amount of nitrogen,phosphorus and potassium fertilizer or optimizing the fertilization period and proportion.Compared with the farmer level,the super high yield level and high yield and high efficiency level significantly increased the leaf area index of each growth period,slowed down the senescence rate of leaves in the later period,optimized the light distribution of canopy,and improved the light energy interception rate and light sum ability.Secondly,the assimilate synthesis ability was enhanced,the photosynthetic potential was increased,and the plant nutrient accumulation and utilization were improved.Finally,the harvest index is improved,so that the yield and the three factors of the yield constitute an overall increase,and then the yield shrinkage effect is achievedCompared with the farmer level,the super high yield level and high yield and high efficiency level significantly increased the accumulation amount of N,P and K in summer maize population growth period,but the utilization rate of N,P and K was low.Nitrogen fertilizer had the greatest effect on the grain yield of summer maize,which could be improved by reducing the amount of nitrogen fertilizer or optimizing the fertilization period and proportion on the basis of high yield and high efficiency level.The effect of phosphorus and potassium on summer maize is relatively small,and the utilization efficiency is low under the condition of this experiment,so the production efficiency can be improved by appropriately reducing the application amount of phosphorus and potassium.