Does maize hybrid intercropping increase yield due to border effects?

Abstract

In China, maize hybrid intercropping has been practiced by farmers for its higher grain yield, but the underlying mechanism remains unclear. Here, we present field experimental data on yield and yield components of maize hybrid cultivars under intercropping system. These cultivars differ in plant heights (i.e. Zhengdan958 with plant height of 270cm, Xianyu335 of 325cm, Huayi5 of 330cm, and Xundan20 of 273cm) and were planted in 8 different intercropping configurations, along with 6 sole cropping treatments in two years. Yield advantages of 0.15–1.7tha−1 were detected under maize hybrid intercropping treatments as compared to sole cropping treatments in one year. Seasonal climate variation and hybrid configuration influenced the interspecific interactions between hybrid cultivars, resulting in different increase of grain yield. Cultivar Zhengdan958 had a lower grain yield per plant and thousand kernel weight under intercropping comparing to sole cropping, while cultivars Xianyu335 and Huayi5 under intercropping increased grain yield per plant and thousand kernel weight, resulting in a land equivalent ratio greater than 1. Additionally, the land equivalent ratio was positively and significantly (P<0.01) correlated with border effects. This study indicates that there is potential for yield improvement of maize hybrids through intercropping system in China, and the land equivalent ratio was affected by hybrids used in intercropping and seasonal climate variation.