Response of growth and yield of spring corn to drip irrigation uniformity and amount in North China Plain

In order to evaluate the suitability of the current design standard for drip irrigation uniformity, field experiments were conducted during growing seasons of spring maize (Zea mays L.) in 2009 and 2010 to study the effects of drip irrigation uniformity and amount on corn growth and yield. Three Christiansen uniformity coefficients (Cu) of 0.66, 0.81, and 0.99 under three levels of irrigation amount (50%, 75%, and 100% of irrigation requirement) were used. The results showed that drip irrigation uniformity and amount had no significant effects on the mean of plant height and leaf area index. The uniformity coefficients for those parameters were increased with spring maize growing and reached more than 0.95 at the end of growing season. Cu values of yield under different irrigation treatments were larger than 0.93 along the drip line. Drip irrigation uniformity and depth as well as their interaction had insignificant effects on the mean and the uniformity of yield. The results suggest that properly lowering the current design standard of drip irrigation uniformity coefficient (Cu≥0.80) of maize in the semi-humid regions such as the north China plain cannot be unfavorable to the growth and yield of crops and can reduce the initial and operation costs of drip irrigation systems.