Relay strip intercropping of oat with maize, sunflower and mung bean in semi-arid regions of Northeast China: Yield advantages and economic benefits

Abstract Intercropping is a sustainable agriculture system that provides an alternative pathway to combat environmental deterioration due to excessively intensive agriculture. However, relay strip intercropping patterns have rarely been practiced in the semi-arid regions of Northeast China. Therefore, two years of field experiments of oat/maize, oat/sunflower, and oat/mung bean relay strip intercropping were conducted to determine the optimal yields and economic patterns. Treatments included sole crops of oat, maize, sunflower and mung bean, as well as three relay strip intercropping patterns consisting of six rows of oat alternating with three rows of maize, sunflower, or mung bean. The land equivalent ratio (LER) of intercrops varied from 1.10 to 1.14, 1.23 to 1.38, and 1.05 to 1.08 for oat/maize, oat/sunflower, and oat/mung bean, respectively. Relay strip intercropping systems presented distinct yield advantages, especially in oat/sunflower. The net incomes of oat/sunflower intercropping were estimated to be ∼2000 $ ha −1 , which were significantly higher than both sole oat and sunflower. In oat/sunflower intercropping, kernel numbers per ear, ear numbers per meter row of oat and the thousand kernel weight of sunflower in border rows were 16–25%, 23–30% and 10–13% higher than inner row, well as thousand kernel weight of sunflower in border row increased 10–13% than inner rows, respectively. However, no positive border row effects were observed in the oat/maize or oat/mung bean intercropping systems. In conclusion, oat/sunflower relay strip intercropping is the most profitable alternative intercropping pattern in the semi-arid regions of Northeast China.