Study on Rational Irrigation for Wheat Production in Fengqiu Region: Ⅰ. Analysis of the Relation Between Soil Water Supply and Wheat Yield

摘要

A 5-year experiment on water balance was conducted in a flat rainfed wheat field with an area of 66 mx 100 m in Fengqiu, Henan Province, China. Results of the experiment showed that the correlation between wheat yield and water consumption was not significant, but that between wheat yield and the ratio of water supply to Penman evaporation was significant, following a parabolic curve. The water consumption process, as well as the growing season of wheat plant, could be divided into three periods. The first (154 days) was vegetative growth period, during which the water consumption accounted for 35% of the total; the second (65 days) reproductive growth period, during which the water consumption occupied 57%, indicating the importance of water consumption in this period; and the third (5～9 days) maturation period, during which water supply was not important to yield formation. According to the statistics of meteorological data over the years in this region, the hydrological conditions of the five seasons covered a probability range of 74.8%. The results (3.46～5.63 t ha~(-1)) indicated that the productivity of the wheat field under rainfed conditions in this region had a degree of confidence of 74.8%.