Yields reaction, Nitrogen uptake and canola qualitative attributes to nitrogen levels and previous plants

in order to Investigation of nitrogen levels and previous plants effects on yield, nitrogen uptake and qualitative traits of canola in Ahvaz climate (condition), an experiment was performed based on randomized complete block design, in split plot, by 3 replication in Agriculture and Natural Resources of Ramin University at 2009-2010. Experimental factors were previous cultivated plants (include: wheat, canola, clover, vetch, corn, rice) in main plot and the nitrogen levels (0,120,180,240 kg/ha-1) sub-plot. The pre planting plants effect on oil and protein percentage of grain was significant (in 1% and 5% levels of confidence, respectively). Highest and lowest amount of canola grain oil with 44.37% and 41.58%, respectively, were obtained from corn and canola preplanting treatments. Also, highest and lowest percentages of canola grain protein were obtained from barley and clover with 20.02%and corn with 18.34% of preplanting treatment, respectively. There was significant difference between different levels of nitrogen about grain oil and protein percentages in 1% level, Highest and lowest percentages of grain oil, were obtained from 0 and 240 Kg nitrogen treatments. Highest and lowest percentages of grain proteins, were abtained from 240 and 0 kg nitrogen treatments, respectively. The effect pre planting plants × nitrogen effects on oil yield was significant in 1% level. Also, preplanting plants effect, on whole the grain protein was significant, by 1% level. Highest and lowest of canola protein percentage were obtained from barley + clover (6.89%), and vetch (5.46%) preplanting, treatment, respectively.