半干旱区坐水种条件下水肥耦合对玉米苗期干重的影响

水分与肥料是影响作物生长的两大因素。在坐水播种条件下，采用“311-B”D饱和最优设计研究了玉米苗期坐水与施肥的耦合效应，对玉米苗地上部干重进行二次回归拟合，建立了各因素的回归数学模型。因素效应分析结果表明，影响玉米苗地上部干重主要因素是坐水量，其次为磷肥，再次为氮肥，各因素交互作用顺序为：NP〉水N〉水P。水肥耦合作用的最佳组合为：略高的坐水量（49．356t／hm2），略低的氮肥量（63．923kg／hm2）和中等的磷肥量（128．25kg／hm2）。

Effects of Water-fertilizer Coupling on Corn at Seedling Stage Under Bed-irrigating Sowing in Semi-drought Area

The moisture and the fertilizer are both of the important factors to effect the growth of the crop. The coupling effect of bed-irrigating sowing and fertilizer at corn seedling stage were investigated by ＂3 ll-B＂ D-sat- uration optimum design. The regressive math model was set up based on the dry weight of corn seedling above ground by quadratic regression analysis. Analysis showed that the water amount in corn bed-irrigating sowing significantly the dry weight of corn seedling above ground. And then were dosage of N fertilizer and the rate of P fertilizer. The interaction effects among these factors with the influenced order as N and P 〉 water amount and N 〉 water amount and P. From the dry weight of corn seedling above ground aspect, The optimum combi- nation of water amount in corn bed-irrigating sowing was 49. 356 t/hm2 somewhat above the middling level un- der the conditions of this experiment, with N and P were 63. 923 kg/hm2 and 128.25 kg/hm2 respectively, somewhat under the middling level of N and around middling level of P.