Nitrogen Redistribution Characteristics of Oilseed Rape Varieties with Different Nitrogen Physiological Efficiency During Later Growing Period

【Objective】In order to reveal the relationship between nitrogen redistribution of oilseed rape varieties and its physiological efficiency during later growing period. 【Method】The differences of nitrogen redistribution in vegetative organs of oilseed rape varieties with different nitrogen physiological efficiency during later growing period were studied using 15N trace method under the sand culture of complete nutrient solution conditions. 【Result】Results showed that high nitrogen physiological varieties had larger amount of organic nitrogen redistribution compared with the low nitrogen physiological efficiency varieties. The speed of nitrogen redistribution was slow at first and then fast,the redistribution amount of nitrogen toward seeds and its proportion was larger,the redistribution amount of nitrogen toward silique husk and its proportion was smaller. The amounts of nitrogen loss from plant and its proportion were smaller,and the velocity of nitrogen loss was slower. This may be one of the main reasons why the varieties with high nitrogen efficiency have high nitrogen harvest indexes. By comparing the redistribution amount of nitrogen and its proportion during the four growing periods,the results indicated that the largest redistribution amount of nitrogen absorbed by plant and its proportion was found in flower bud stage,the smallest redistribution amount and its proportion at siliquing stage,and those were between them at seeding and flowing stages.【Conclusion】During later growing period,nitrogen redistribution in vegetative of oilseed rape varieties had significant effect upon its nitrogen physiological efficiency.