Relevance of Sprinkler Irrigation Time and Water Losses on Maize Yield

Abstract

Daytime sprinkler irrigation with a solid‐set system can result in higher water losses, lower uniformity, and lower maize (Zea mays L.) yield compared with nighttime irrigation. We studied the relevance of irrigation time (daytime or nighttime) and water losses (compensating them or not in the irrigation applied) for the growth and yield of maize during 2 yr. The seasonal average sprinkler water losses compensated ranged from 14 to 19% for daytime irrigation and from 5 to 11% for nighttime irrigation. The average Christiansen coefficient of uniformity (CU) was similar for daytime and nighttime irrigation in 2009 (84%) but lower for daytime irrigation (78%) than nighttime irrigation (84%) in 2010. Daytime irrigation decreased the maize grain yield by 9% in the year that the CU was reduced. Increasing the water applied to compensate the water losses increased the soil matric potential but did not increase maize yield. The lower irrigation uniformity for daytime sprinkler irrigation compared with nighttime sprinkler irrigation seems to be a relevant reason for the yield reduction. Solid‐set sprinkler irrigation systems for maize should be designed to minimize daytime irrigation or to allow a high daytime irrigation uniformity (>84%).