半干旱农田生态系统地膜覆盖的土壤生态效应  

Soil ecological effects of plastic film mulching in semiarid agro-ecological system

作　　者：李世清[1] 李东方[1] 李凤民[2] 白红英[1] 凌莉[1] 王俊[2] 

机构地区：[1]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨陵712100 [2]兰州大学干旱农业生态国家重点实验室,甘肃兰州730000

出　　处：《西北农林科技大学学报（自然科学版）》2003年第5期21-29,共9页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(30230230;90102012);2002年度教育部全国优秀青年教师资助项目(20022096);中国科学院知识创新重要方向项目(KZCX-411);黄土高原土壤侵蚀与旱地农业国家重点实验室基金(10501-104)

摘　　要：　在年降水量415mm的黄土高原中部黄绵土和年降水量632mm的黄土高原南部红油土上,分别以春小麦和冬小麦为供试作物进行大田试验,研究地膜覆盖(春小麦设不覆膜、播种后覆膜30d、覆膜60d和全程覆膜4个水平;冬小麦设不覆膜、播种后覆膜75d、覆膜150d和全程覆膜4个水平)和施氮(春小麦设不施氮和每公顷施氮75kg2个水平;冬小麦设不施氮和每公顷施氮225kg2个水平)对土壤水分、温度、氮素有效性、土壤中CO2和N2O释放量的影响。结果表明,在2年的春小麦试验中,覆膜对2m深土层的贮水量基本没有影响,但能显著提高0～20cm土层的含水量;覆膜对5cm土层土壤温度的影响呈"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;覆膜后虽然土壤微生物体氮有下降趋势,但由于覆膜能够增加土壤呼吸和有机氮的矿化,从而显著影响收获后0～100cm土层中NO-3-N的累积。从2个施氮水平和底墒平均值看,1999年覆膜30,60d和全程覆膜(126d)处理土层中累积的NO-3-N分别比不覆膜的对照增加-23.0,-10.1和49.7kg/hm2;2000年覆膜30,60d和全程覆膜处理土层中累积的NO-3-N分别比不覆膜的对照增加4.6,-5.0和8.2kg/hm2。可见,全生育期覆膜能够显著增加作物收获后土壤剖面中的残留NO-3-N。不同覆膜进程对作物收获后土壤剖面中的矿质氮,特别是NO-3-Field experiments have been carried out on Loess Plateau in middle part with 415 mm average precipitation and in south part with 632 mm precipitation per year.In these experiments,spring wheat (Triticum aestivum) and winter wheat (Triticum aestivum) have been used as indicating crops to study the effects of plastic film mulching (for spring wheat included no mulching,mulching for 30 days and 60 days after sowing,and mulching for the whole growth period,and for winter wheat included no mulching,mulching for 75 days and for 150 days after sowing,and mulching for the whole growth period) and nitrogen fertilizer application (for spring wheat including no nitrogen application and nitrogen application 75 kg N/hm2,and for winter wheat including no nitrogen application and nitrogen application 225 kg/hm2) on soil moisture,temperature,nitrogen availability,the flux of CO2 and N2O in soil.The results showed that,in 2 years experiment on spring wheat,plastic film mulching almost didnt affect the soil water storage amount in 2 m soil layer,but could increase the soil water content in 0-20 cm layer significantly;and the effect of plastic film mulching on soil temperature in 5 cm layer changes as the 'U' pattern,that is,the effect was significant at early and latter growth stage,and was insignificant at middle growth stage;plastic film mulching decreased the soil microbial biomass nitrogen,but increased the soil respiration and the mineralization of soil organic nitrogen,so it could significantly affect the accumulation of residual NO-3-N in 0-100 cm layers after harvest:the averages of the soil storage water amount before sowing of 2 levels of nitrogen application showed that the accumulation of NO-3-N respectively increased by -23.0,-10.1 and 49.7 kg/hm2 in treatments of mulching for 30 days,60 days and the whole growing period (126 d) than CK of no mulching in 1999;Under the same condition,in 2000,its respectively increased by 4.6,-5.0 and 8.2 kg/hm2,so it was obvi

关 键 词：半干旱农田 生态系统 地膜覆盖 土壤生态效应 黄绵土 年降水量 大田试验 累积量 小麦 

分 类 号：S512.1[农业科学—作物学] S158.3