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利用ArcGIS9.0软件中嵌套地质统计模块分析河套灌区浅层地下水埋深(2009年)空间分布状况,结合在2010年3-7月间开展的灌溉量、施氮量和浅层地下水埋深对春小麦产量和土壤中硝态氮淋溶损失影响的显著性以及最优组合研究,确定出适用于河套灌区内不同区域的春小麦农业管理的最优综合模式。研究表明,表层(0～80 cm)土壤含水率随着浅水埋深的增大而减小,当浅水埋深≥2.0 m时,在同一浅水埋深水平下灌溉量成为土壤含水率显著影响因子;对春小麦产量影响程度高低是浅水埋深>灌溉量>施氮量,影响显著因子为浅水埋深;对硝态氮淋溶量影响程度高低是灌溉量>施氮量>浅水埋深;灌溉量对硝态氮淋溶影响呈极显著性,施氮量对其影响呈显著性,而浅水埋深起到辅助作用。灌区年均浅层地下水埋深主要有3个阈值:1.25～1.75、1.75～2.25和2.25～3.00 m。在灌区内浅水埋深不同区域内(1.5、2.0和2.5 m)时,三因素最优综合组分别为灌溉量(280 mm)+施肥量(尿素150 kg.hm-2,二铵165 kg/hm2)、灌溉量(320 mm)+施肥量(尿素150 kg/hm2,二铵165 kg/hm2)和灌溉量(360 mm)+施肥量(尿素255 kg/hm2,二铵375 kg/hm2)。
The spatial distribution of shallow groundwater depth (2009) in Hetao Irrigation District was analyzed by using the nested geostatistical module in ArcGIS 9.0 software. Based on the amount of irrigation, amount of nitrogen application and shallow groundwater depth during the period from March to July in 2010, On the spring wheat yield and soil nitrate leaching loss of the significance of the combination and the optimal combination of research, to determine the Hetao irrigated areas in different regions of the optimal management of spring wheat agriculture integrated mode. The results showed that the water content of surface soil (0 ~ 80 cm) decreased with the increase of shallow water depth. When the depth of shallow water was 2.0 m, irrigation at the same depth of shallow water became a significant factor ; The effect on spring wheat yield was shallow water depth> irrigation amount> nitrogen application rate, and the significant factor was shallow water depth; the influence degree of nitrate leaching was irrigated amount> nitrogen application amount> shallow water depth; irrigation The amount of nitrate leaching had a significant effect on nitrogen leaching. The effect of nitrogen application was significant, while the depth of shallow water played an auxiliary role. There are three main thresholds for annual average groundwater depth in irrigation district: 1.25 ~ 1.75, 1.75 ~ 2.25 and 2.25 ~ 3.00 m. In the different depths of shallow water in the irrigation area (1.5, 2.0 and 2.5 m), the optimum combination of three factors were irrigation (280 mm) + fertilizer (urea 150 kg.hm-2, diammonium 165 kg / hm2), the amount of irrigation (320 mm) + the amount of fertilizer (urea 150 kg / hm2, diammonium 165 kg / hm2) and irrigation amount (360 mm) .