Coupling Effect Of Water And Fertilizer With Sprinkler Irrigation On Maize Yield In The West Of Heilongjiang Province

The issue of continuous grain yield and grain yield has been one of the most serious problems faced by mankind in the twenty-first Century.It is even more urgent for China,whose population accounts for 22%of the world's population.Heilongjiang province is an important grain production base in China.It is of great significance to improve the grain output of Heilongjiang province to ensure the food security of our country.However,Heilongjiang province is located in semi arid and semi humid regions of China.Rainfall is uneven in crop growth period,and it is prone to drought and water shortage.At the same time,irrational fertilization and lack of water in crop growth period are also important factors that restrict the development of local agriculture.Therefore,it is an important measure to solve the grain problem in Heilongjiang by using efficient irrigation mode and seeking reasonable water and fertilizer application scheme.In this study,maize was select as study object,D-416 saturated optimal design was applied to study the coupling effect of water and N,P,K under sprinkler irrigation.By comparative analysis,variance analysis,regression analysis and other methods,the different treatments of water and fertilizer of maize height,stem diameter,leaf area,photosynthetic rate,yield,water consumption and water use efficiency were analyzed,and used the multi-objective optimization genetic algorithm to find the optimal ratio of corn fertilizer.The results were as follows:?1?The effect of irrigation and fertilization on the photosynthetic rate of maize from large to small was:irrigation amount,N,K and P.The effect of the four factors on the photosynthetic rate increased first and then decreased with the increase of the encoding value.Water and N,P and K,water and K had significant coupling effect,and the coupling effect of the other factors was not significant.There was a positive interaction between water and N,P and K and there was a negative interaction between K and water.?2?Using regression analysis,it was concluded that the effect of various factors on maize yield in descending order were:N,P,irrigation amount and K,all had significant positive effect,and the effect of N on the yield was significantly higher than other factors.In the coupling effect,there was a positive interaction between N and K,P and K,and there was a negative interaction between N and P,N and water,P and water,K and water.?3?The effects of irrigation and fertilization on the water use efficiency of maize were from large to small:N,P,K and irrigation amount,and the four factors were positive effects.N and K,P and K were positive interaction,N and P,N and water,P and water,K and water were negative interaction.?4?A multi-objective optimization model of maize photosynthesis rate,yield and water use efficiency was established,and the optimal combination of water and fertilizer was obtained by using the multi-objective genetic algorithm.The most suitable combination of irrigation water amount and fertilizer was as follows:irrigation amount was 700m³/hm²,and the fertilizer was 270kg/hm² of N,60.08 kg/hm² of P₂O₅,60.02 kg/hm² of K₂O and the corresponding optimum maize photosynthetic rate,yield and WUE were 20.80?mol/?m²·s?,17421.04 kg/hm² and 3.72 kg/m³respectively.?5?The economic benefit analysis of the best water and fertilizer combination based on multi-objective genetic algorithm was carried out.The results show that under the combination,the net profit of corn per hectare was 8392 Yuan/hm².Compared with the local traditional cultivation model,the yield was increased by 74.2%,and the economic benefit was increased by61.5%.In this paper,a comprehensive study on the photosynthetic rate,yield and water use efficiency of maize is conducted by regression analysis,which has a certain reference value for the rational regulation of corn water and fertilizer application programs in agricultural production.The corn optimal water and fertilizer ratio obtained by the multi-objective genetic algorithm achieves the purpose of saving water and fertilizer,increasing yield and improving economic efficiency.It has guiding significance for improving maize yield,water and fertilizer utilization efficiency in low-yielding fields in the west of Heilongjiang Province.The rationality of the application of sprinkler irrigation in the western region of Heilongjiang is verified.