施氮对不同种植密度玉米产量和子粒灌浆特性的影响

以玉米品种先玉335为供试材料,在大田条件下设2个氮肥水平、5个种植密度,探讨施氮量与密度互作对玉米子粒灌浆特性影响,通过Logistic方程拟合子粒灌浆过程,解析灌浆特征参数与粒重的关系。在玉米子粒灌浆过程中,氮肥主要调控灌浆前期的灌浆速率来影响子粒建成,最终使百粒重增加;密度则调控快增期、缓增期持续天数来影响子粒重。要提高玉米产量,关键在于提高子粒灌浆速率和有效灌浆时间,尤其是延长快增期和缓增期持续时间以及提高渐增期平均灌浆速率。在生产中,首先要合理密植,构建适宜的群体,延长子粒灌浆持续时间;此外,通过增加开花后的氮肥供应来提高子粒灌浆前期的平均灌浆速率。

Effect of Nitrogen Application on Yield and Grain Filling Characteristics under Different Densities of Maize

Used Xianyu335 as the material, a field experiment was conducted at two N levels and five planting densities to discuss the effect of nitrogen application and density on grain filling of maize. The grain-filling process-es and the relationship between a series of secondary parameters and grain weight were analyzed by Logistic model. The results showed that the role of nitrogen fertilizer on grain filling process was mainly affected the grain filling rate at the early stage of filling and eventually increased the grain weight; the role of density was mainly affected grainfilling duration of middle stage and late stage. The key to increase the grain yield was improving the grain filling rate and prolonging the active grain-filling period, especially prolonged the grain-filling duration of middle stage and late stage and improved the mean grain-filling rate of early stage. In practice, planting at rational density and build-ing appropriate groups, prolonging grain filling duration could improve grain yield of maize. Furthermore, by increas-ing the nitrogen supply to improve mean grain-filling rate of early stage after flowering was also very important.