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作 者 ：李世清,李凤民,宋秋华,王俊

期 刊 ：生态学报 2001年 21卷 9期 页码：1519~1526

关键词：旱地土壤；地膜覆盖；土壤养分；NO-3-N累积；

Keywords:dryland soil, plastic film mulching, soil nutrients, accumulation of nitrate nitrogen,

摘 要 ：在年降水量 4 1 5 mm的半干旱地区黄绵土上 ,以春小麦为供试作物进行大田试验 ,研究地膜覆盖 (包括不覆膜、播种后覆膜 3 0 d、覆膜 60 d和全程覆膜 )对土壤水分、温度和氮素有效性的影响。结果表明 ,覆膜对 2 m土层贮水量基本没有影响 ,能显著提高 0～ 2 0 cm土层的含水量 ;覆膜对 5 cm处土壤温度的影响呈“U”型变化 ,即在作物生长前期和后期影响显著 ,中期影响较小 ;覆膜能增加土壤呼吸和有机氮的矿化 ,因而显著影响土壤剖面中 NO- 3-N的累积 :表现为在收获时覆膜 3 0 d和 60 d处理剖面中 NO- 3-N的累积明显下降 ,而全程覆膜处理剖面中 NO- 3-N的累积显著增加 ,在覆膜的基础上施用氮肥 ,这种作用会更加突出。显然全程覆膜易造成有机质的大量矿化和 NO- 3-N的淋溶损失。

Abstract:A field experiment was carried out on cultivated loessial soil in semiarid areas with 415 mm precipitation and spring wheat ( Triticum aestivum L.) used as an indicating crop to study the effects of the plastic mulching periods on the soil nitrogen availability.The experiment had three factors and they were water storage in soil profile before sowing,plastic film mulching period and nitrogen fertilization.The water storage in soil profile before sowing had two levels under each of which there were no mul...

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