Crop Management Affects the Performance of a Winter Pea–Wheat Intercrop

Abstract

Cereal–legume intercropping systems may show improved agronomic and environmental performance over sole crops depending on the intercrop management. This study aimed at investigating the effect of sowing and fertilizer management on the performance of a winter pea (Pisum sativum L.)–wheat (Triticum aestivum L.) intercrop. A 2‐yr experiment was performed in Grignon, France. Intercrop management strategies varied in sowing proportion relative to the sowing density of sole crops (50:50, 66:33, and 50:70 for pea and wheat, respectively) and N fertilization (without N fertilization, conventionally fertilized, and overfertilized at different dates). Conventionally managed sole wheat and sole pea were used as controls. The total grain yield, wheat yield proportion at harvest, yield components, N efficiency, grain protein concentration, residual soil mineral N after harvest, and land equivalent ratios (LER) were compared. The fertilized 50:50 intercrop was a good compromise between production (yields and wheat protein concentration), N efficiency, and limited residual soil N. The unfertilized 50:50 intercrop had the lowest grain yields and wheat protein concentration. An early overfertilization increased the proportion of wheat yield at harvest, whereas a late overfertilization increased the wheat grain protein concentration. Increasing the proportion of pea at sowing was a good way to produce more pea yield. Increasing the sown wheat proportion with N fertilization led to a higher proportion of wheat yield at harvest but did not improve the wheat grain protein concentration. These results indicate that agronomic management markedly impacts intercrop performance, and management practices can be adjusted to meet farmers’ production targets. Sowing rate and N fertilization impacts the agronomic performances of a pea–wheat intercrop. Intercrop management has to be adapted to the farmer's production targets. Conventionally managed intercrop is a compromise between production and environmental impacts. Overfertilization may increase wheat production and protein concentration. Producing more pea implies increasing pea proportion at sowing and decreasing N fertilization.