灌水对棉田土壤矿质氮运移的影响

以阿拉尔垦区棉田为试验地点,采用8100、6600、5100、3600m3·hm-24个灌水水平,对5次灌水后100cm土层NO3--N、NH4+-N含量进行了分析.结果表明:在4～9月整个种植周期内,0～60cm土层的养分浓度均呈下降趋势,60～100cm土层养分的浓度则缓慢上升,灌水量越大,深层养分的浓度越高;当土壤NO3--N累积量较大时,不同灌水处理间土壤NO3--N含量的变化非常显著;灌水对土壤铵态氮运移影响远小于对硝态氮的影响.

Effects of different irrigation amount on mineral nitrogen transportation in the soil of cotton field

Taking Alar irrigated area as experiment site, taking four irrigation treatments:8 100,6 600,5 100 and 3 600 m3·hm-2, and the contents of NO3--N, NH4+-N in 0~100 cm soil after 5 times of irrigation were measured. The results showed that the nutrient concentration tended to go down in the upper soil layer, and to increase gradually in the deeper soil layer of the cotton field, the nutrient concentration of deeper soil layer increased along with the increasing of irrigation amount; the variation of NO3--N content was significant between the irrigation treatments when accumulation of NO3--N was higher in soil;effect of different irrigation amount on NH4+-N transportation was significantly smaller than on NO3--N transportation, leaching loss of NO3--N may be one of the main way for nitrogen losses in the cotton field of Alaer irrigated area.