摘要
[Objective] The experiment was conducted to explore the suitable planting density and nitrogen amount for summer maize in Sichuan Basin with the objective to provide technical reservation and scientific basis for high-yielding cultivation technique.[Method] A widely planted maize cultivar ＇Chengdan 30＇ was used as experimental material to study the effects of planting density and nitrogen amount on the stalk agronomic traits,stalk lodging-resistance mechanical characters,stalk breaking percentage and yield of maize.Experiment was arranged in a two-factor split plot design with three replicates.The planting density was the main factor with three density gradients（4.5×10^4,6.0×10^4 and 7.5×10^4 plants/hm^2） and the nitrogen amount was the second factor with two different levels of nitrogen content（300 and 375 kg/hm^2）.[Result] The stalk lodging-resistance and yield were affected by planting density significantly.The increase of planting density would result in an increase of internode length and decrease of internode diameter,dry matter weight of per unit stalk length,rind penetration strength and breaking resistance of 3rd and 4th basal internodes.When planting density increased from 6.0×10^4 plants/hm2 to 7.5×10^4 plants/hm^2,the stalk breaking percentage in the whole growing season increased by 17.17%,and the yield reduced by 17.58%.The interaction between planting density and nitrogen amount affected the stalk breaking percentage in the whole growing season and yield significantly.The treatment with planting density of 6.0×104 plants/hm^2 and nitrogen amount of 375 kg/hm^2 of pure N was an optimal combination,which may not only control the stalk breaking percentage of whole growing stage effectively,but also could obtain an optimum grain yield.[Conclusion] In Sichuan Basin,the appropriate planting density and nitrogen amount for summer maize were 6.0×10^4 plants/hm^2 and 375 kg/hm^2.
[目的]探明四川盆地直播夏玉米适宜种植密度和施氮量,为夏玉米高产栽培提供技术储备和科学依据。[方法]在大田条件下采用二因素裂区设计,研究密度和施氮量对夏玉米的茎秆基部节间农艺性状、节间抗倒力学性状、玉米茎折率和产量的影响。[结果]密度显著影响玉米茎杆抗倒性能和产量。随着密度增加,茎秆基部第3节和第4节节间伸长变细,单位茎长干物质重变小,穿刺强度和抗折力降低,种植密度由6.0万株/hm2增加到7.5万株/hm2,全生育时期茎折率增加17.17%,产量下降17.58%。密度和施氮量互作显著影响玉米全生育时期茎折率和产量,当密度为6.0万株/hm2、施氮量为375kg/hm2能够有效控制全生育时期茎折率,且玉米产量达到最高。[结论]本试验条件下,四川盆地夏玉米适宜种密度为6.0万株/hm2,适宜施氮量为375kg/hm2。
基金
Supported by the Special Fund for Agricultural and Rural Research in the Public Interest of Sichuan Province(12ZC1930)~~
