改土型专用肥对玉米田物理性质和玉米经济性状及效益的影响

Effects of Soil Improved Special Fertilizer on Physical Properties of Cornfield and Corn Economic Traits and Benefits

在甘肃省河西地区内陆灌区连作8a的制种玉米田上,采用田间试验方法,研究了改土型专用肥与制种玉米田物理性质和玉米经济性状及效益间的关系。结果表明,影响玉米产量的因素依次是:CO(NH2)2>(NH4)2HPO4>PVA和ZnSO4.7H2O;因素间最佳组合是:PVA 30kg/hm2,CO(NH2)2 736kg/hm2,(NH4)2HPO4420kg/hm2,ZnSO4.7H2O 52kg/hm2。随着改土型专用肥施用量的增加,玉米田总孔隙度、毛管孔隙度、非毛管孔隙度、团聚体在增大,而容重在降低。改土型专用肥施用量增加后,玉米植物学性状、经济性状、产量在增加,但单位(1kg)改土型专用肥的增产量则随着改土型专用肥施肥量的增加而递减,出现报酬递减律。随着改土型专用肥施用量的增加,玉米边际产量、边际利润在递减,改土型专用肥施用量在1 350kg/hm2的基础上,再增加337.50kg/hm2,收益出现负值。经济效益最佳施肥量为1 350.01kg/hm2,玉米理论产量为6 700.99kg/hm2。

In Hexi irrigation area of Gansu Province managed for eight year corn seed production,field test method was used to study the relationships among soil improved special fertilizer,physical properties of seed production cornfield and corn economic traits and benefits.Results showed that the factors affecting corn production followed the order of CO（NH2）2 （NH4）2HPO4 PVA and ZnSO4·7H2O.Best combination for the factors is 30 kg/hm2 PVA,736 kg/hm2 CO（NH2）2,420 kg/hm2（NH4）2HPO4 and 52 kg/hm2 ZnSO4·7H2O.With the increases of soil improved specific fertilizer,corn field total porosity,capillary porosity,non-capillary porosity and aggregates increased,but bulk density decreased.When soil improved special fertilizer application increased,corn botanical traits,economic traits and yield increased,but yield increment by unit（1 kg） amount of soil improved special fertilizer decreased gradually with the increase of soil improved special fertilizer,showing the law of diminishing return.With the increased amount of soil improved special fertilizer,marginal corn yield and profit in the reduced profit margins.The additional 337.50 kg/hm2 application rate over the 1 350 kg/hm2 soil improved special fertilizer made revenue to be negative.The optimum economic fertilization capacity was 1 350.01 kg/hm2 and theoretical corn yield was 6 700.99 kg/hm2.