Clarifying the effect of intercropped green manure on the yield sustainability of maize under different irrigation levels plays a crucial role in the development of a water-saving and efficiency-oriented maize and leguminous green manure intercrop-ping system.Field experiments were conducted from 2018 to 2022 using a split-plot experimental design,including two planting patterns:maize and green manure intercropping(M/V)and sole maize cropping(SM).Three irrigation levels were implemented:local conventional irrigation(I3:4000 m3 hm-2),15%reduction in irrigation(I2:3400 m3 hm-2),and 30%reduction in irrigation(I1:2800 m3 hm-2).The effects of intercropped green manure on maize yield,yield components,relative multi-crop resistance index,yield sustainability index,key soil nutrient indicators,and economic benefits under different irrigation levels were investigated.The results indicated that intercropped green manure increased the number of maize kernels and thousand-kernel weight when subjected to a 15%reduction in irrigation,compared to sole maize cropping,resulting in enhanced grain yield.From 2019 to 2022,intercropped maize with a 15%reduction in irrigation exhibited an increase in the number of maize kernels and thousand-kernel weight by 8.7%-16.4%and 7.1%-13.4%,respectively,compared to sole maize cropping.Grain yield also increased by 9.3%-23.6%.There was no significant difference in grain yield between intercropped maize with a 15%reduction in irrigation and local conventional irrigation.The relative multi-crop resistance index of intercropped maize under reduced irrigation was greater than 0 and increased with the duration of planting,reducing the coefficient of variation in yield and increasing the yield sustainability index of maize.Under the same irrigation levels,the coefficient of variation in yield of intercropped maize de-creased by 77.9%-82.8%,and the sustainability index increased by 12.2%-19.9%compared to sole maize cropping.Maize inter-cropped with green manure also led to increased soil nutrient levels compared to sole maize cropping.Soil organic matter and available nitrogen content increased by 6.4%-15.8%and 12.1%-35.6%,respectively.Soil available phosphorus content in maize and green manure intercropping with a 15%and 30%reduction in irrigation increased by 19.4%and 11.3%,respectively,com-pared to sole maize cropping.The content of soil organic matter,available nitrogen,and available phosphorus in maize and green manure intercropping with a 15%reduction in irrigation showed no significant difference compared to local conventional irriga-tion but was significantly greater than other treatments.The net income of intercropped maize with a 15%reduction in irrigation increased by 10.5%-34.2%compared to sole maize cropping from 2020 to 2022.From 2021 to 2022,the investment ratio of intercropped maize with a 15%reduction in irrigation increased by 7.8%-10.4%compared to sole maize cropping and showed no significant difference compared to intercropped maize with local conventional irrigation.Intercropped green manure improved the yield sustainability of maize by increasing soil organic matter and improving soil nitrogen and phosphorus conditions.In summary,intercropped green manure can mitigate the yield loss of maize caused by reduced irrigation,enhance the stability and sustainabil-ity index of maize under reduced irrigation.In this investigation,maize and common vetch intercropping with an irrigation level of 3400 m3 hm-2 can serve as a reference for sustainable maize production and suitable irrigation levels in the experimental region.
关键词
产量稳定性/产量可持续性/间作绿肥/减量灌水/玉米
Key words
yield stability/sustainability yield/intercropped green manure/reduced irrigation quota/maize
维普
万方数据