Effect of phosphorus application and strip-intercropping on yield and some wheat-grain components in a wheat/maize/potato intercropping system

Intercropping of bread wheat (Triticum aestivum L.), maize (Zea mays L.) and potato (Solanum tuberosum) has been practiced in North-West China in the last several decades; however, the effects of this intercropping and phosphorus addition on crop yield and some wheat-grain components have not been adequately investigated. A 2-year field experiment was conducted from 2002 to 2003 in irrigated areas in North-West of China to investigate how phosphorus fertilizer application and intercropping of wheat/maize/potato impact on the crop yield and wheat-grain components such as protein content, wet gluten and sodium dodecyl sulphate (SDS) sedimentation. The results indicated that bread wheat and maize achieved higher yields in the intercropping system than in the monoculture system over the 2 years, and the wheat-grain had higher protein content, wet gluten and sodium dodecyl sulphate (SDS) sedimentation in the intercropping system than in the monoculture system. Better utilization of resources through border row effect and preventing competition between species over growing period have been indicated as the major factors contributing to the increased crop yield and wheat-grain components. Phosphorus application significantly increased crop yields and improved wheat-grain components; however, the optimal application rate for achieving highest protein content was at 150 kg ha(-1). The practical implication of the present study was that to obtain good yield and better wheat-grain components, a combination of intercropping and application of phosphorus fertilizer at a rate of approximately 150 kg ha(-1) was found as one of the most practical options.