Comparison of different irrigation methods to synergistically improve maize’s yield, water productivity and economic benefits in an arid irrigation area

Abstract

Water scarcity is everywhere and more prominent in arid and semi-arid regions. Moreover, water allocation for irrigation is hit by other economic sectors for low per capita profit. It is inevitable to extend higher-efficient irrigations to replace conventional border irrigation. A three-year field experiment was conducted to examine the effects of different irrigation methods on maize’s water use and economics in the Hetao Irrigation District of China. Taking 525-mm border irrigation as the control, furrow and drip irrigations at three water levels were implemented. Furrow irrigation included 100 % (450 mm), 80 % (360 mm) and 60 % (270 mm) of the recommended level, while three threshold values of soil matric potential: −10 kPa, −30 kPa, and −50 kPa, were used to trigger drip irrigation. The grain yield, ETc (water consumption for the whole growing season), ETcs (water consumption during a special growth stage), and water productivity were affected significantly by the irrigation methods and water levels. The average ETc of border, furrow and drip irrigations was 537.4 mm, 401.8–514.4 mm, and 306.6–496.2 mm for different levels, respectively. On average 10 % of the irrigation water was lost through deep percolation under border irrigation, while 10.5–29.0 mm of groundwater contributed to ETc under drip irrigation with −50 kPa. The higher Kwc (water consumption coefficient) was observed in R3-R6 (Milk-Maturity) stages under drip than border and furrow irrigations. The lower Ky (yield response factor) of drip (0.68) than furrow (0.82) indicated the lesser reduction in yield induced by the decreased ETc under drip irrigation. The 360-mm furrow irrigation obtained a comparable grain yield and net profit with the control, but reduced water application by 31 %. Drip irrigation at −30 kPa enhanced yield by 15 %, increased net profit by 23 %, and reduced water application by 57 %. Thus, drip irrigation at −30 kPa is recommended as the priority to replace border irrigation for maize production in the study area. If drip irrigation is unavailable, a 360-mm furrow irrigation is also an alternative to reduce water application without compromising benefit.