Water use and yield of wheat/maize intercropping under alternate irrigation in the oasis field of northwest China

A field experiment was carried out to investigate the effects of alternate irrigation (AI) on the yield, water use and water use efficiency (WUE) of wheat (Triticum aestivum L.)/maize (Zea mays L.) intercropping system in an oasis region of northwest China in 2006–2008. Three planting patterns, i.e., sole wheat, sole maize and wheat/maize intercropping. Three irrigation levels were applied for each treatment during 3 years. Results showed that land use efficiency of wheat and maize was significantly enhanced by intercropping system; land equivalent ratio (LER) of wheat/maize intercropping system in different treatments was all greater than 1.0. Moreover, significant difference in grain yield was observed between intercropping treatment and sole cropping treatment, in which the yield of intercropped wheat was 55.37–74.88% of sole wheat, and intercropped maize was 66.63–78.87% of sole maize. Wheat/maize intercropping treatments increased water use by 1.8–16.4% than half of the total water use of sole-cropping wheat and maize. Compared to sole cropping wheat treatments, wheat/maize intercropping with alternate irrigation significantly improved water use efficiency (WUE) by 30.5–57.7%, 55.5–71.4% and 12.0–19.8%, and increased by 32.7–37.8%, 9.5–15.8% and 4.0–20.8% than sole cropping maize treatments in 2006–2008, respectively. Our results suggest that AI should be a useful water-saving irrigation method on wheat/maize intercropping in arid oasis field where intercropping planting is decreased because of limited water resource.

► The first study to apply alternate irrigation in wheat/maize intercropping.
► Planting patterns have significant impacts on yield of wheat and maize.
► Total water use of wheat/maize intercropping with alternate irrigation was not significantly increased.
► Wheat/maize intercropping with alternate irrigation can significantly improve water use efficiency