功能性肥料对制种玉米田物理性质和微生物数量的影响及最佳施肥量的研究

在甘肃河西内陆灌区的灌漠土上，采用田间试验方法，研究了功能性肥料对制种玉米田物理性质、微生物数量的影响及最佳施肥量。结果表明：影响玉米产量的因素由大到小依次为：CO(NH2)2>(NH4)2HPO4>抗重茬剂和聚乙烯醇。因素间最佳组合是：A3B2C1D1(即抗重茬剂30 kg/hm2，CO(NH2)2 600 kg/hm2，(NH4)2HPO4 350 kg/hm2，聚乙烯醇30 kg/hm2)。功能性肥料施用量与制种玉米田总孔隙度、毛管孔隙度、非毛管孔隙度、团聚体、微生物数量呈线性正相关关系，与制种玉米田体积质量呈线性负相关关系。随着功能性肥料施用量梯度的增加，玉米边际产量、边际利润在递减，功能性肥料施用量在1 350 kg/hm2的基础上，再增加337.50 kg/hm2，收益出现负值。经回归统计分析，功能性肥料施用量与玉米产量间的肥料效应回归方程是：y = 3 782.61 + 1.650 5x - 0.000 378 7 x2，功能性肥料经济效益最佳施肥量(x0)为1 350.01 kg/hm2，玉米理论产量(y)为6 700.99 kg/hm2，计算结果与最佳施用量试验处理5相吻合。

Effects of Functional Fertilizer on Physical Properties, Microorganism Amount and Optimal Fertilization of Seed-production Corn Field

In the irrigation desert soil of Gansu Hexi inland irrigation area, the field experiment method was conducted to study the effects of functional fertilizer on soil physical properties, microorganism amount and optimal fertilization of seed-production corn field. The results showed that the influence factors of maize yield was in the order of CO (NH2) 2 > (NH4)2HPO4 > resistance to continuous cropping agent and polyvinyl alcohol. The optimal combination was A3B2C1D1 (resistance to continuous cropping agent 30 kg/hm2, CO (NH2)2 600 kg/hm2, and (NH4)2HPO4 350 kg/hm2, polyvinyl alcohol 30 kg/hm2). The application amount of functional fertilizer had linear positive correlation with total porosity, capillary porosity, noncapillary porosity, aggregate and microbial quantity while had linear negative correlation with soil bulk density. With the increase of functional fertilizer application gradient, corn marginal output and profit margins decreased. Earnings appeared negative value when the application amount of functional fertilizer increased by 337.50 kg/hm2 on the basis of 1350 kg/hm2. The regression equation of fertilizer response between application amount of functional fertilizer and corn yield was: y = 3782.61 + 1.6505 x - 0.000 378 7 x2, the optimal application amount of functional fertilizer (x0) was 1 350.01 kg/hm2 with corn theoretical yield (y) of 6 700.99 kg/hm2. The calculation results coincided with best surveyed test treatment 5.