中高产麦田水分变化规律及节水灌溉方案的研究

1986～1990年,在高产地力条件下,进行了麦田水分变化规律及节水灌溉方案的研究。研究的主要结果:1.麦田0～300cm土层的土壤水分,可分为苗期供水层、中期供水层、后期供水层及稳定供水层等层次。2.小麦亩产184.9～456.1kg,耗水量为147.5～451.6mm。高产(400kg以上)小麦耗水量为338～536mm。耗水量的水源分别来自:降水占31.1％～53.7％,灌水占23.4％～33.6％和土壤供水占22.8％～32.7％。3.0～140cm上层的供水量为107～233mm,约占土壤有效贮水量的1/3～1/2。4.高产麦田的节水灌溉方案:灌水次数2～3次;灌水量低限80～115mm,高限125～180mm,干旱年份取高限。灌水时期:播前(底墒)、起身(二棱期)或拔节期、孕穗或灌浆期。

STUDIES ON VARIATION OF WATER CONTENT IN MEDIAL AND HIGH YIELD WHEAT FIELDS AND WATER-SAFE IRRIGATION SCHEME

The main results of study from 1986 to 1990 as follows: 1. According to water supply, the soil depth of 0-300 cm in wheat field could be divided into four layers, i. e., the layers of 0-40, 40-120, 120-200, and 200-300 cm supply water to wheat at stages of seedling, joi nting-booting, booling-maturing, and full ripening, resp. 2. The water consumption was 147.5-451.6 mm under the conditions of wheat grain yield of 2873-6841 kg ha~(-1) and 338-536 mm under high-yielding conditions (over 6000 kg per ha). The source of water consumption was 31.1-53.7% from precipitation, 23.4-33.6% from irrigation and 22.8-32.7% from soil moisture. 3. The amount of water supply in 0-140 cm depth of soil layers was 107-233 mm, about 1/3-1/2 of soil available water-storage capacity. 4. The water-safe irrigation scheme for high-yielding could be practised to water for 2-3 times in stages of presowing, the start of noding or jointing, and booting or filling at 80-115 mm in minimum and 125-180 mm in maximum.