宽窄行种植下不同施氮量对春玉米冠层物质生产性能的影响

Effects of Nitrogen Application Rates on Productivity of Spring Maize under Wide and Narrow Row Planting

为了探索宽窄行种植下春玉米施氮量对冠层物质生产性能的影响,以农华101为供试材料,在7.5万株·hm^-2种植密度下,设常规施氮(N1:300 kg·hm^-2)、常规减量30%(N2:210 kg·hm^-2)和常规减量50%施氮(N3:150 kg·hm^-2)3个氮肥水平,测定了不同生育时期叶面积指数、SPAD值、干物质量,并计算干物质积累量及分配比例.结果表明,N1与N2水平产量差异不显著,N1和N2水平显著高于N3水平;叶面积指数各生育期都均表现为N1>N2>N3,生育后期叶面积衰减表现为N3>N2>N1;叶片SPAD值在吐丝期和乳熟期各个层位叶片均随施氮量的减少而减小;干物质积累量呈现随施氮量减少而减小趋势,但N1与N2差异不显著.西辽河平原灌区在12 000 kg·hm^-2左右产量水平下,高产高效的适宜施氮量是210 kg·hm^-2.

The effect of nitrogen application rate on production performance of spring maize,Nonghua 101 under wide and narrow row planting was investigated. At a density of 75 000 plants·hm^-2 three levels of nitrogen fertilizer were applied:conventional nitrogen application(N1:300 kg·hm^-2),conventional reduction of 30%(N2:210 kg·hm^-2)and conventional reduction of 50%(N3:150 kg·hm^-2). The leaf area index,SPAD value and dry matter quality of different growth stages were measured,and the dry matter accumulation and distribution ratios were calculated. There was no significant difference in yield between N1 and N2 levels. N1 and N2 levels were significantly higher than N3 levels. Leaf area index showed N1>N2>N3 at all growth stages,and leaf area attenuation showed N3 >N2 > N1 at late growth stage. Leaf SPAD values decreased with the decrease of nitrogen application at all layers during silking and milk maturity. Dry matter accumulation decreased with the decrease of nitrogen application,but N1 and N2 were not significantly different. Under the production level of 12 000 kg·hm^-2 in the irrigation area of Xiliaohe Plain,the suitable nitrogen application rate of high yield and high efficiency was found to be 210 kg·hm^-2.