种植密度与施氮量对宁夏玉米产量和氮肥肥效的影响

The Impact of Planting Density and Nitrogen Application Rate on Corn Yield in Ningxia and Nitrogenous Fertilizer Efficiency

为实现玉米超高产,在宁夏引黄灌区,以先玉335为材料,选择种植密度(x1)和施氮量(x2)为调控因子,采用二因子正交旋转组合设计,对不同种植密度和施氮水平下玉米产量和氮素肥效进行了研究.结果表明,收获穗、穗粒数、百粒质量和空杆率达到1%的极显著水平,秃尖长达到5%的显著水平.玉米产量与种植密度、施氮量二因素的回归模型Y=14 431.2+1 109.2 X1+2 104.3 X2-36.1 X1X2-1 334.0 X12-1 022.6 X22(R=0.967 8),回归项检验达到极显著水平,失拟项检验不显著,即模型的预测值与实际值吻合很好.先玉335最佳种植密度X1=9.10万株/hm2、最佳施氮量X2=398.0kg/hm2,玉米最高产量Ymax=15 729.24kg/hm2.对当地玉米高产栽培具有重要的参考价值.

In order to achieve super high yield of maize in Ningxia irrigation area, the researchers took Xianyu 335 as materials, the density factor （xl） and nitrogen application rate （xz） as control factors, and applied two-factor orthogonal rotational combination design to study the formation of maize yield and nitrogenous fertilize efficiency under different planting density and different nitrogenous application level. It turns out that the harvested spike, kernels per spike, hundred-grain weight, and empty bar rate of regression model in key economic traits reached 1 ~ （the extremely significant level）, and the length of tip-barrenness reached 5 % （the significant level）. It can be seen from the research that all maize yield components must be taken into consideration, esttecially the combined effect of harvested spike, kernels per spike, and hundred-grain weight. The regression model of maize yield and two factors - planting density and nitrogen application rate： Y = 14431.2 -t- 1109.2 xl ＋ 2104. 3 xz -- 36.1 X1 SC2 -- 1334.0x^--1022.6x~ （R=0. 967 8）. The statistical analysis shows that the regression was tested to the extreme significant level, and the lack-of-fit is not significant, which means the predicted value of the model is well identical to the actual value. The optimal planting combination to get Xianyu 335, on the basis of function extreme value, is： planting density（X1 ）=91.0 thousand/hmz , net nitrogen application rate（Xz）=398. 0 kg/hmz , the maximum maize yield can be Ym^x = 15 729. 24 kg/hmz. This research is very instructive for the local high production cultivation