Technology and the Effects of Supplemental Irrigation with Catchment Rainwater on Maize in the Hilly-Arid Area of Northern China

Abstract

Abstract. Efficient use of rainwater is one of the focuses of water resources research around the world, especially in arid and semi-arid regions. Following the rainfall-runoff balance principle of cropland and the theory of rainwater reiterative use, an experiment was designed to investigate the technology and effects of supplemental irrigation with catchment rainwater on maize in the hilly-arid area of northern China. The results showed the following: (1) a water cellar with 60 m3 of storage volume provided enough water for 1.33 ha of maize seedlings with no mulching film and for 5.33 ha with mulching film; (2) compared with the non-irrigated control (CK), when maize received 15 to 45 mm of supplemental irrigation at different growth stages, there was a 0.17 m increase in average plant height, a 0.52 to 0.55 cm increase in average stem diameter, and a 2.61 to 2.84 cm increase in average panicle length; and (3) the booting stage of maize was the best stage for increasing production and rainwater use efficiency (RWUE) with supplemental irrigation, which increased maize production by 22.1% on average for the two years of the study and improved RWUE by 5.2% compared with CK on average for the two years. The sufficient amount of supplemental irrigation was 30 mm, and spare rainwater could be used to irrigate a larger area. The results indicate that the best periods for supplemental irrigation of maize in the hilly-arid area of northern China was during sowing in the spring drought and during the growth stage. Keywords: Catchment rainwater, Hilly-arid area, Rainwater use efficiency, Supplemental irrigation, Water cellar.