晋南丘陵旱地小麦不同降水模拟条件下土壤水分变化规律的研究

在万荣试区丘陵旱地麦田上,500mm降水可基本满足小麦前期、中期需水,后期表现缺水,是旱地小麦丰欠的临界值;400mm降水在拔节时水分已严重不足,从开花前后开始整个土层即处于凋萎值以下,维持生长主要靠中后期不参与土壤水分循环的间隙性少量降水.本试验600mm降水亩产近400千克,但该降水量仍不是继续高产的上限值,深厚黄土的良好蓄水保水特性与生产潜力尚待进一步开发.

Study on the Changing Pattern of Soil Water Content under Different Simulated Rainfall Conditions in Hilly Dry Wheat Land in Southern Shanxi

500 mm rainfall can satisfy the wheat water demand in early and middle growing stages, but the effects of water deficiency will appear in the later stage of growth, so that 500 mm is the critical amount of rainfall for a good yield. 400 mm rainfall can cause severe water deficiency in the jointing stage. The whole top soil layer water content will be too low to prevent withering after the flowering stage. In the middle and later stages wheat growth can only depend on the small smount of rainfall which does not participate in soil water circulation. The yield can reach near, 400 kg/mu with 600 mm rainfall in our experiment. The harvesting polentiality and high water storage capacity of deep loess need be exploited in the future.