不同水肥条件对马铃薯肥料N利用率的影响

Effect of different watering and fertilization on N utilization efficiency

在旱棚控制条件下 ,用五因素五水平二次回归正交旋转组合设计 ,研究了水肥施用分配 ,补水量 ,施N量 ,施K量 ,有机肥施用量的综合作用效应 .结果表明 ,五因素对肥料N利用率的作用顺序为施N量 >补水量>水肥施用分配 >有机肥施用量 >施K量 .水肥施用分配相对于不同水、化肥 (N、K )、有机肥量的选择 ,可以大大地提高肥料N利用率 ;量少应重前施用 ,量多重后施或均施为好 .补水量与施N量的耦合规律为 :高水高肥效果最佳 ,肥料N利用率可达 5 7 83 % ,中水中N及低水低N次之 ,为 2 9 17%～ 40 99% ;高水低N或低水高N导致最低的利用率 ,为 2 2 87%或 2 2 5 1%

The comprehensive effects of the timing of watering and N and K fertilization(D),amount of irrigated water(W),and application rates of chemical N and K fertilizers,and farm manure(M) were studied by the design of orthogonal regression rotation with five factors and five levels under dry greenhouse condition.The N utilization efficiency of potato was in order of N>W>D>M>K.Under different application rates of W,N,K and M,the N utilization efficiency was significantly increased with optimum timing of watering and fertilization.When the application rate was low,the timing should be earlier,while it was high,the timing should be later.High application rates of W and N resulted in the best interaction effect,with 57 83% of N utilization efficiency;moderater W and N or low W and N had 29.17～40 99% of efficiency;and high W and low N or low W and high N resulted in the lowest efficiency,with 22.87% and 22.51 %,respectively.