Analysis Of Water Use Efficiency And Influencing Factors Of Wheat And Maize Under Different Irrigation Strategies

Aiming at the contradiction between the high supply and demand of wheat and maize grain production and the continuous reduction of water resources in my country,a systematic analysis of crop yield and water use efficiency under different irrigation quotas of winter wheat and summer maize in the Huanghuaihai region was carried out to optimize irrigation system and provide the basis.In this study,field experiments,WHCNS model simulation and Meta analysis were used to explore the changes of crop growth dynamics,farmland water balance components,yield and water use efficiency under different irrigation quota treatments.The field experiment took the winter wheat-summer maize planting pattern as the research object,and set three different irrigation quota treatments(R: rainfed;D: deficit irrigation;F: full irrigation).The Meta analysis method collected 64 published literatures,established 423 sets of databases including irrigated and non-irrigated wheat and maize yield and water use efficiency,and obtained the yield-increasing effect and water effect of irrigation under different factors.Effects of characteristics and management measures on wheat and maize yield,evapotranspiration and water use efficiency.The main conclusions are as follows:(1)The field test results showed that the overall growth traits and yield of winter wheat under different treatments were D treatment > F treatment > R treatment.Compared with the rainfed treatment,the yield of winter wheat in the D treatment increased significantly by 38.46%.The aboveground biomass of the F treatment was significantly higher,but the water use efficiency and irrigation water use efficiency of the D treatment were increased by 27.98% and 48.03% compared with the F treatment;the annual water use efficiency of the D treatment(18.14 kg·hm-2·mm-1)was the highest There was no significant difference between treatments in summer maize yields in 2020and 2021.(2)The WHCNS model simulation and verification results showed that the root mean square error is less than 1,and the R2 is over 0.77;with the increase of irrigation amount,the field evapotranspiration and field leakage of winter wheat increase.Utilization and consumption of ineffective water.(3)Meta results showed that compared with no irrigation during the growth period,irrigation increased the overall yield of wheat and maize by 28.66%,evapotranspiration by 25.98%,and water use efficiency by 5.60%.The most important factors affecting crop yield,evapotranspiration and water use efficiency in wheat and maize irrigation systems were crop type,irrigation level and organic matter,followed by annual average temperature.(4)After irrigation,the relative growth rates of yield and water use efficiency in areas with annual average temperature ≤10°C were higher than those in areas with annual average temperature >10°C;when the regional average annual rainfall was 200-400 mm,irrigation could make yield and water use efficiency separate.Increased by 28.89%and 17.67%.When the soil type was loam,the bulk density was 1.3-1.4g·cm-3,the organic matter was 10-15g·kg-1,and the total nitrogen content was 1-1.5 g·kg-1,the effect of irrigation was the most significant.Among the management measures,crop rotation,drip irrigation,and furrow and ridge planting significantly improved the yieldincreasing effect of irrigation,and the irrigation quota of 80-160 mm was more conducive to improving the yield and water use efficiency of wheat and maize.