单 位：
中国科学院寒区旱区环境与工程研究所临泽内陆河流域研究站;中国科学院寒区旱区环境与工程研究所黑河生态水文与流域科学实验室
摘 要：
研究了不同农田利用方式和冬灌对黑河中游边缘绿洲沙地农田土壤硝态氮(NO3-N)积累的影响.结果表明:不同农田利用方式0～300cm土层NO3-N含量平均值介于1.27～83.60mg·kg-1;受土壤结构、施肥及灌溉的影响,NO3-N含量在0～40cm和135～300cm土层含量较高,40～135cm土层含量较低;不同农田利用方式下的土壤剖面NO3-N含量差异极为明显,大棚蔬菜地各土层NO3-N含量均显著高于其他农田利用类型,土壤NO3-N累积量表现为大棚蔬菜地>番茄地>棉花地>制种玉米连作田>小麦-玉米轮作田>小麦/玉米间作田>苜蓿地>枣树园;大棚蔬菜地0～300cm土层土壤剖面NO3-N累积量高达2171.45kg·hm-2,对地下水污染的威胁较为严重,番茄地和棉花地土壤剖面NO3-N累积量次之,粮田、苜蓿地和枣树园土壤剖面NO3-N累积量较小,但其污染潜力仍不容忽视.冬灌前后NO3-N含量随土壤层次表现出不同的变化规律,0～80cm土层冬灌后NO3-N含量低于冬灌前,并且随灌溉量的增加NO3-N含量呈明显降低趋势;80～300cm土层基本表现为冬灌后NO3-N含量高于冬灌前,且随灌溉量的增加NO3-N含量呈增加趋势;冬灌前后0～80cm土层土壤剖面NO3-N的损失量基本为正值,80～300cm土层基本为负值,并且随灌水量的增加表层土壤NO3-N损失量增大,表明冬灌是造成土壤累积的NO3-N向深层淋溶的主要原因.从减少淋溶和地下水污染的角度考虑,需要合理地调整土地利用方式,适当减少高NO3-N积累作物的种植,并确定合理的冬灌方式和灌水量.
译 名：
Effects of farmland use type and winter irrigation on nitrate accumulation in sandy farmland soil
作 者：
YANG Rong1,2, SU Yong-zhong1,2(1Linze Inland River Basin Comprehensive Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 2Heihe Key Laboratory of Ecohydrology and Intergrated River Basin Science, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China)
关键词：
winter irrigation; farmland use type; sandy farmland; soil NO3-N
摘 要：
With the sandy farmland in the marginal oasis in middle reaches of Heihe River Basin, Northwest China as test object, this paper studied soil NO3-N accumulation and leaching under effects of different farmland use type and winter irrigation. The results showed that the mean NO3-N concentration in 0-300 cm soil profile in different farmlands ranged from 1.27 mg·kg-1 to 83.60 mg·kg-1. Soil NO3-N concentration was higher in 0-40 cm and 135-300 cm layers, but lower in 40-135 cm layer. Greenhouse vegetable field had a significantly higher soil NO3-N concentration than the other farmland use types. The accumulated amount of soil NO3-N decreased in the order of greenhouse vegetable field>tomato field>cotton field>seed maize field>maize-wheat rotation field>maize-wheat stripe intercropping field>alfalfa field>jujube plantation. The NO3-N accumulation in 0-300 cm soil profile in greenhouse vegetable filed reached 2171.45 kg·hm-2, which would be a serious menace to groundwater quality, followed by tomato field and cotton field. Lesser accumulation of soil NO3-N was found in seed maize field, maize-wheat intercropping field, maize-wheat rotation field, alfalfa field, and jujube plantation, but its pollution potential would not be neglected. After winter irrigation, soil NO3-N concentration decreased in 0-80 cm layer but increased in 80-300 cm layer, indicating that winter irrigation caused NO3-N leaching into deeper soil depth. The leached amount of soil NO3-N to deeper layers increased with increasing amount of winter irrigation. To mitigate soil NO3-N leaching and groundwater contamination, a comprehensive consideration should be made on the rational arrangement of farmland use type, proper decrease of planting N-accumulated crops, and reasonable winter irrigation.
