Effects of the nitrogen and zinc fertilizers and salinity irrigation on yield, quality traits and nutrient uptake of canola (Brassica napus L. cv. Okapi)

Soil or water salinity is one of the major problems of agriculture in the arid and semiarid regions of the world، especially in Iran. Beside the Salinity، reasonable canola production depends on nutrient supply so that increase in quantitative and qualitative yield is highly correlated with nutrients availability، especially nitrogen and Zinc. In order to investigate the effects of the nitrogen، zinc fertilizer and irrigation salinity on yield quality characteristic and nutrient uptake of canola (Brassica napus L. cv. Okapi)، a field experiment was conducted in Agriculture Research Centre of East Azarbaijan، Iran in 2009-2010. The experiment was arranged by using a completely randomized block design based on factorial fashion with three replications. The experimental treatments included the nitrogen levels (0، 50 and 100 kg. ha-1)، different zinc levels (0، 5 and 10 kg. ha-1) and irrigation salinity levels (8 and 16 dS. m-1). Based on results، nitrogen and zinc application had a significant effect of increasing plant height، number of pod per plant and grain yield of canola. However، mentioned traits of canola were decreased as result to increasing irrigation salinity levels (from 8 to 16 dS. m-1). Irrigation salinity at rate of 16 dS. m-1 had a significant effect on increasing glucosinolate percentage in seed. In addition، effect of irrigation salinity levels on decreasing the N، P، Ka and Ca uptake and increasing the Na and Cl accumulation in seed canola were significant. In sum، it seems that nutrient supply، especially nitrogen، can be considered as effective solution to diminish negative effects of salinity.