秋覆膜对旱地玉米土壤水分和产量的影响

针对甘肃省旱作农业区年降水量少、季节分布不均匀、玉米生产中春旱严重的问题,采用田间试验的方法,研究了4种不同覆膜时期对旱地玉米生育期、土壤水分变化、水分利用效率、产量及经济效益的影响。结果表明,全膜双垄沟秋季覆膜优于顶凌覆膜、春覆膜和播前覆膜,即早覆膜优于晚覆膜。全膜双垄沟秋覆膜增加了降水利用率和水分利用效率,降水利用率为70.21%,产量为10039.34kg/hm ^2,比播前覆膜增产24.81%,水分利用效率30.19kg/（hm ^2·mm）,比播前覆膜提高15.26%。全膜双垄沟秋覆膜可明显减少冬春季土壤水分的无效蒸发,增加土壤水分含量,使玉米的经济性状明显改善,增产增收,是旱作区进一步挖掘降水潜力和高产田创建的有效途径。

Effects of Full Mulching on Double Ridges in Autumn on Soil Water Content and Yield of Dryland Maize

Aiming at the water requirement of maize growth at the situation of limited and unevenly distributed rainfall and the problem of serious spring drought in Gansu dry farming area, a field trial with a maize variety Funong No.1 was conducted during 2008-2010 in Lanzhou, Gansu, China, to investigate the effects of four different plastic film mulching time on growth duration, soil moisture variation, water use efficiency, yield and economic benefit of dry land maize. It is found that the full mulching on double ridges in autumn was better than full mulching on double ridges in early spring and full mulching on double ridges in middle spring and full mulching on double ridges before sowing, the early film mulching was batter than latter film mulching. The full mulching on double ridges in autumn increased rainfall use rate and water use efficiency. Rainfall use rate of the full mulching on double ridges in autumn was 70.21%, water use efficiency was 30.19 kg/（hm ^2 ·mm）. The yield of corn production with the full mulching on double ridges in autumn was 10039.34 kg/hm ^2 , which was higher 24.81% than the full mulching on double ridges before sowing as well as water use efficiency raised 15.26%, respectively. These results indicated that the way of full mulching on double ridges in autumn couldreduce the useless evaporation of soil water in winter and spring , increase soil moisture content, improve the economic characters of maize and increase the yield of maize and net income. It was an effective way to further exploit rainfall productive potential and create high-yielding fields in dry farming areas.