STUDIES ON VARIATION OF WATER CONTENT IN MEDIAL AND HIGH YIELD WHEAT FIELDS AND WATER-SAFE IRRIGATION SCHEME
Qi Xinhua, Yu Zhenwen, Liu Fang, Tian Qizhuo, Xu Yumin (Dept. of Agronomy, Shandong Agri. Univ., Taian, China 271018)
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.
【CateGory Index】： S512.107.1