Abstract
A study to elucidate the possibility of water-saving irrigation methods for maize (Zea mays L.) by reducing frequency and wetting area was conducted in 2013 and 2014 on Vertisols of the Nile Delta. The water-saving methods tested were prolonging the interval by about 1 week and strip method with wide planting bed which results in reducing number of irrigation ditches by 50%. The water-saving ratio was higher with strip method (26 - 31%) than prolonging the interval (8 - 19%). The growth, photosynthetic rate, and grain yield of maize plants were investigated under 4 treatments, i.e. the combination of interval (about 2 weeks or 3 weeks) and method (furrow or strip). Although the treatments had different effects in 2 years, our results can suggest that prolonging the interval by about 1 week from the conventional interval has a risk of yield reduction in the field with soil clay contents equal to or less than 50%, while, strip method has possibility to sustain the grain yield of maize and to improve water use efficiency, calculated as the grain yield divided by the total amount of irrigation water, as much as 71% when irrigation interval was practiced as conventional. Under the prolonged irrigation interval, maize with strip method showed low photosynthetic rates caused by water deficit. Thus, the strip irrigation method with the conventional interval is recommended for saving limited water resources without yield reduction of maize in the Egyptian Nile Delta.
