Effects of drought stress on fertilizer use efficiency of rapeseed during wintering

Seasonal drought often occurs in Southern China; however, the research related to effects of drought stress on NPKB fertilizer use efficiencies of rapeseed is few. Field experiments were carried out to study the differences of NPKB fertilizer use efficiencies of rapeseed under natural drought stress and timely irrigation during the wintering stage. The results show that the growth of rapeseed is obviously inhibited and yield is significantly decreased under the drought stress. The amplitude reductions of the various fertilizer treatments are different, and the order is-B＞-K＞-N-PNPKB, which indicates that reasonable and balanced fertilization could effectively improve the droughtresistance of rapeseed. The results also prove that the fertilization could promote plant growth and increase the yield of rapeseed significantly, especially for the N fertilization which has the best efficiency whether under the drought stress or adequate moisture condition, and the fertilizer use efficiencies of P, K and B under the drought stress are obviously higher than those under the adequate moisture condition. The fertilization and irrigation have some positive interactive effects on the yield of rapeseed. These results demonstrate that the fertilizer applications have more significant effects on the improvement of rapeseed yield under the drought stress, and the high yield of rapeseed is more dependent on the fertilization.