Effects of Irrigation Period on Growth and Water Consumption Characteristics of Winter Wheat

Abstract

【Background】 In Jinzhong wheat area, Water resources are insufficient and water use efficiency is low. To irrigate properly and timely to improve water use efficiency is essential to sustainable production of local wheat. 【Objective】 The purpose of this paper is to investigate the effects of irrigation period on agronomic characters, flag leaf photosynthesis and water consumption characteristics of winter wheat. 【Method】 A randomized block design was conducted with no irrigation during the whole growth period as the control (CK), and 7 treatments were set: irrigation at overwintering stage (Wo), irrigation at jointing stage (Wj), irrigation at booting stage (Wb), irrigation at overwintering and jointing stage (Wo+j), irrigation at overwintering and booting stage (Wo+b), irrigation at jointing and booting stage (Wj+b), and irrigation at overwintering, jointing and booting stage (Wo+j+b). 【Result】 Compared with CK, the plant height, the number of green leaves, the area of the second leaf from the top and dry matter weight of winter wheat in heading stage were significantly increased by 28.80%, 18.82%, 34.67% and 45.56% in Wo treatment, and by 26.12%, 6.14%, 43.73% and 46.38% in Wo+b treatment. Delayed irrigation could delay the senescence of flag leaves. Wo+b, Wj+b and Wo+j+b treatments could prolong the photosynthetic function period of flag leaves and maintain higher photosynthetic rate, transpiration rate and stomatal conductance after anthesis. Overwintering water was beneficial for winter wheat to use deep soil water and improve irrigation use efficiency. With the increase of irrigation water, the water consumption of winter wheat and the proportion of irrigation amount to water consumption increased, the proportion of precipitation to water consumption decreased, the irrigation use efficiency and irrigation benefit decreased, the grain yield of winter wheat increased, and water use efficiency increased first and then decreased. Wo+b treatment could obtain higher yield, water use efficiency, irrigation use efficiency and irrigation benefit concurrently, and make great use of irrigation and precipitation. 【Conclusion】 In the irrigated wheat area, irrigation at overwintering and booting stages can meet the water requirement for winter wheat growth, and obtain higher yield and water use efficiency concurrently in Jinzhong.

Keywords

• irrigation period
• winter wheat
• agronomic trait
• photosynthetic characteristics
• water consumption
• water use efficiency