种植密度与施肥量对小麦抗倒伏性能的影响

摘要

为明确小麦抗倒伏能力与种植密度（Z）、施氮量（N）、施磷量（P）、施钾量（K）间的关系，并为完善小麦高产栽培理论提供参考，以倒伏指数作为评价小麦抗倒伏能力的指标，通过四元二次旋转设计试验，研究了倒伏指数与茎秆机械强度、鲜重、重心高度间的相关性，并建立了倒伏指数与 Z、N、P、K 的回归方程。结果表明：倒伏指数与茎秆机械强度（－0．826**）相关性最大，其次为茎秆鲜重（－0．489**），均呈极显著负相关；四个因素对倒伏指数的影响程度为施钾量（88．921）＞种植密度（77．061）＞施氮量（38．639）＞施磷量（3．736）；倒伏指数与四个因素均成二次曲线关系，表现为随着种植密度增大，倒伏指数逐渐增大，但增速逐渐变缓；随着施氮量与施钾量增加，倒伏指数先增加后缓慢减小，随着施磷量增加，倒伏指数先缓慢增加后迅速增加。%To make sure the relations of wheat lodging resistance with planting density (Z),nitrogen a-mount(N),phosphorus amount(P)and potassium amount(K)and to provide references for completing the high -yielding cultivation theory,the correlations of lodging -resistant index with stem mechanical strength, fresh weight and gravity center height were researched by an orthogonal rotational regression combination de-sign of 4 factors.The regression equations were constructed for lodging -resistant index with Z,N,P and K. The results showed that the stem mechanical strength showed the maximum correlation with lodging -resistant index,and the next was stem fresh weight.They both had very significantly negative correlation.The influ-ence degree of the 4 factors was K(88.921)>Z(77.061)>N(38.639)>P(3.736).The lodging -resistant index showed quadratic curve relationship with any one of 4 factors.With the increase of planting density,the lodging -resistant index increased gradually with slower and slower speed.With the increase of N and K ap-plication rates,the lodging -resistant index increased firstly and then decreased slowly.And with the increase of P application rate,the lodging -resistant index increased slowly at first and then rapidly.