Dynamic variations of soil moisture and water use efficiency of maize under sprinkler irrigation

In order to study irrigation quota of maize and water saving effect of sprinkler irrigation on Erdos Plateau, a large-scale field experiment was conducted in sprinkler irrigation base of maize in Saiwushu town of Erdos from May to October, 2009. Dynamic variations of soil moisture in maize field, maize yield and its components, water consumption and water use efficiency (WUE) under sprinkler and pipeline irrigation were tested and quantitatively analyzed. The results showed that the changed range of soil moisture in sprinkler treatment was less than that under pipeline irrigation throughout maize growth period. Soil moisture in 20-60cm layer was slightly higher than the other layers in sprinkler treatment. Water infiltration rate under sprinkler irrigation was lower than that under pipeline irrigation. Sprinkler irrigation quota affected kernel number per ear and seed weight per kernel, and thus maize yield, and slightly affected the ear number on stalk. Difference in yields of maize under sprinkler and pipeline irrigation was not significant when sprinkler irrigation quota was higher than 4965 m3/hm2. WUE was 1.26kg/m3 in sprinkler irrigation quota of 5430 m3/hm2 (17.76% higher than that of pipeline irrigation). The ratio of irrigation to water consumption was 70.40%-88.90%, and it increased with irrigation quota. Without well watered from sowing to seedling stage, numbers of ears on stalk was declined.