evaluation of competitive and economic indices in canola and pea intercropping at different rates of nitrogen fertilizer

the experiment was conducted in order to evaluate of competitive and economic indices in canola and pea intercropping at different rates of nitrogen fertilizer at shahrekord university research farm during 1390 - 1391. intercropping and sole cropping treatments (100% canola; 66% canola + 33% pea, 50% canola + 50% pea; 33% canola + 66% pea; 100% pea) were evaluated as the first factor and nitrogen rates (100% need; 75% need and 50% need) as the second factor in a randomized complete block design with three replications. the calculated competitive indices were included land equivalent ratio (ler), relative crowding coefficient (k), aggressively (a), the system production index (spi), actual yield loss (ayl), competitive ratio (cr) and economy indices included monetary advantage index (mai), and the intercropping advantage (ia). results showed that all the competitive and economic indices had the highest amount in 50 and 75% of nitrogen requirement. the amounts of aylt and spi and economic indices (mai and ia) were positive for all intercropping ratios. also, lert and kt for all intercropping ratio were greater than one, that indicating the superiority of intercropping over sole cropping any of the two plants. the positive values aggressively index and the greater than one values competitive ratio for canola, indicated canola was superior competitor in compared to pea. in conclusion, the evaluation of competitive and economic indices appropriately describes intercropping advantage of canola with pea in reduced nitrogen fertilizer conditions.