东北黑土区大豆生长、结瘤及产量对氮、磷的响应

摘要

The N and P fertilization impact the nodulation and yield of soybean significantly , however , there are not many reports on these in the Northeast China where the soil fertility is relatively high .Split plot field experiments were conducted to study the effects of N (0, 20 and 50 kg/ha), P (0, 20 and 40 kg/ha) and N ×P interaction on soybean growth , nodulation characteristics and yield .The results show that the high rate of individual N application increases the biological and grain yield of soybean , but decreases the number , dry weight , size and nodulation index of nodules .High rate of individual P fertilizer increases the grain yield , nodule number , dry weight , size , nodulation index , although the increments in grain yield are lower than those of the N treatments .Compared with the control and the individual N or P application , the interactive effect of N and P ( N ×P) demonstrates the highest biomass and yield, but there are no significant differences among the N , P and N ×P treatments.The nodule number, dry weight, size and nodulation index with N ×P are lower than those of the individual P application , and the nodule number, dry weight, size and nodulation index of the N2 treatment (N 50 kg/ha) are higher than those of the N1 treatment (N 20 kg/ha).The increased P application rate offsets the negative effect of high N application rate on nodulation to some extent .The effects of N , P and N ×P treatments on nodulation characteristics indicate that the N and P have direct effect on the nodulation , and not via plant growth .Therefore , both N and P are the key factors to the nodulation and yield of soybean in Northeast China .To maximize soybean yield , the N and P application rates should be at 50 kg/ha and 40 kg/ha, and to maximize soybean nodulation and nitrogen fixation , the N and P application rates should be at 0, 20 N kg/ha and 40 P kg/ha.%氮肥和磷肥显著影响大豆的结瘤和产量。然而在土壤肥力较高、速效养分有效性差的东北地区，有关氮肥和磷肥施用量对大豆结瘤和产量影响的研究较少。本试验采用裂区田间试验，设置3个氮（ N ）水平（0、20和50 kg/hm2）和3个磷（ P）水平（0、20和40 kg/hm2），研究氮、磷及其交互作用对大豆生长发育、结瘤特征及产量的影响。结果表明：单施氮肥大豆生物量和产量随着施氮量的增加而增加，而根瘤数量、干重、大小和结瘤指数呈逐渐下降的趋势。单施磷肥促进大豆生物量、产量、根瘤数量、干重、大小和结瘤指数的增加，但其增幅低于施氮处理下的增幅。氮×磷对大豆生长和产量促进作用高于单施氮和单施磷处理，但差异不显著；氮×磷处理下的根瘤数量、干重、大小和结瘤指数低于单施磷处理；氮×磷处理下N2（ N 50 kg/hm2）处理下的大豆根瘤数量、干重、大小和结瘤指数高于N1处理（ N 20 kg/hm2）下的，随着施磷量的增加大豆根瘤数量、干重、大小和结瘤指数增加，施磷能够抵消氮对大豆根瘤产生和形成的抑制。氮、磷及其交互作用对大豆根瘤的影响都是直接的，并且不是通过促进大豆生长间接促进的。因此氮和磷均是限制东北地区大豆结瘤和产量的因素，但氮是主导因素。若要获得大豆高产，氮肥施用量需要控制在50 kg/hm2，磷肥在40 kg/hm2；但若想最大的发挥大豆的结瘤固氮功能，那么应该不施或者减少氮肥的施用量到20 kg/hm2，磷肥仍在40 kg/hm2。