In the oasis irrigated agricultural region, the low resource utilization efficiency and the ratio of output/input are the most prominent constraints for crop production. In this study, the characteristics of light use efficiency, irrigation water productivity and economic benefit in different cropping patterns were investigated in the areas. Research on the sustainability of different cropping patterns would benefit crop production to save cost and increase income in this region.

A field experiment was carried out in a typical arid irrigation area, Wuwei, Gansu province, from 2018 to 2020, to determine the effects of different cropping patterns on leaf area duration, grain yields light utilization efficiency, irrigation water productivity and economic benefit of crops. The sustainability of different cropping patterns was evaluated based on the above indexes.

Multiple cropping of green manure after spring wheat harvested significantly increased the leaf area duration of the main-cultivate crops during the whole growth period. W-G//M increased leaf area duration of the main-cultivate crops by 7.7%-7.8%, compared with W//M. Compared with sole cropping and spring wheat-green manure multiple cropping, the intercropping increased the grain yield of main-cultivate crops and the inputs of production cost, simultaneously. There was no significant difference in the total grain yield between W-G//M and W//M in 2018 and 2019. However, W-G//M increased the total grain yield by 8.7% in comparison to W//M in 2020. Compared with M, W-G and W, W-G//M increased net return by 16.7%-26.5%, 78.5%-132.2% and 35.9%-78.8%, respectively. In two intercropping patterns, the net return of the W-G//M decreased by 7.2% in comparison to W//M treatment in 2018. However, the net return of two intercropping treatments showed not significantly different in 2019 and 2020, and the ratio of output/input showed a similar result. Multi-planting green manure after wheat harvested could significantly improve the light use efficiency of crops. W-G//M treatment increased light use efficiency by 7.2%-14.1% compared with W//M. The light use efficiency under W-G was increased by 23.5%-52.1% in comparison to W treatment. Compared with W, the productivity of irrigation water under W-G was significantly reduced by 48.6%-54.3% (irrigation water use efficiency) and 30.9%-39.8% (Economic benefit per cubic meter irrigation water), while there was no significant difference in the productivity of irrigation water under W-G//M and W//M. W-G//M had the highest sustainability index across three years.

Grain yield of main-cultivate crops and economic benefits were improved by intercropping and multiple cropping green manure after wheat harvested. The irrigation water productivity and light utilization efficiency were also increased, thereby improved the sustainability of this cropping pattern. Therefore, multiple cropping green manure after wheat harvested in wheat/maize intercropping could be used as a high-efficient utilization of resources and sustainable cropping pattern in arid irrigation areas.