Optimization of Use of Nitrogen for Growth and Yield of Canola and Pea Intercropping

In order to investigate the effects of deficit nitrogen application on growth and yield in sole cropping and intercropping of canola and pea, a factorial experiment was conducted as randomized complete block design with three replications at Shahrekord University Research Farm, Sharekord, Iran during 2011- 2012 growing season. Five planting ratios (100% canola; 66% canola + 33% pea, 50% canola + 50% pea; 33% canola + 66% pea; 100% pea) were evaluated as the first factor and three levels of nitrogen (100%, 75% and 50% N requirement of canola and pea) as the second factor. Results showed that intercropping in comparison to sole cropping led to increase in the plant height of pea (23.64%) but it decreased canola plant height (7.32%). Total dry matter of canola and pea increased in intercropping treatments (38.56 and 6.15 %, respectively) compared to sole cropping. In canola sole cropping, seed yield increased (21.9%) with increase in nitrogen application, however in intercropping the greatest seed yield was observed in 75% plant nitrogen requirement. The crop yield in intercropping treatments with application of 50 and 75% plant nitrogen requirement was higher than sole cropping of either crop, but crop yield in pea – canola 66-33% and 50- 50% with 100% plant nitrogen requirement was decreased compared to their sole cropping. In conclusion, intercropping of 33% canola + 66% pea and/or 50% canola + 50% pea, in addition to potentiating an acceptable grain yield for both crops, it can conserve the environment with reducing of nitrogen fertilizer application.