Long-term water productivity of maize (Zea mays L.) from limited Irrigation conditions under moderate semi-arid environment

Abstract

Crop production has a correlation with the applied water in moderate semi-arid conditions. Due to temperature and rainfall changes enhancing water productivity in crop production are needed for a limited resource conditions. In this study, maize (Zea mays L.) yields measured in fields during 11 years from 2005-2006 to 2015-2016 were compared with those simulated by the Agro-ecological Zone method under moderate semi-arid environment located at the north west of Iran with a soil texture of loamy-clay. Different research scenarios involving actual evapotranspirationc (ETa) to potential (ETm) value (ETa/ETm= 100%, 90%, 80%, 70%, 60%, 50% and 40%) under different water application efficiencies (Ea) of 40%, 50%, 60%, 70%, 80%, 90% and 100% were considered in the present study. Research scenarios affected yield and water productivity of maize. To produce potential yield of maize of 10084 kg ha-1 under water application efficiency of 100, 90, 80, 70, 60, 50 and 40%, irrigation water requirements were respectively 4683, 5203, 5854, 6690, 7805, 9366, 11708 m3 ha-1 and water productivity were respectively 2.15, 1.94, 1.72, 1.51, 1.29, 1.08, 0.86 kg m-3. Results confirmed that water productivity of maize was from 1.22 to 1.52 kg m-3 with an average of 1.38 kg m-3 during 11 years under water application efficiency of 68%. Because measured yield ranged from 3800 to 6971 kg ha-1 with an average of 5345 kg ha-1 and water applied was from 3125 to 4584 and averaged 3836 m3 ha-1. It is suggested that limited irrigation could be applied to enhance water productivity in maize production under such moderate semi-arid environment.