Development of deficit irrigation for maize crop under drip irrigation in samaru-nigeria
Keywords:Aqua Crop model, calibration, validation, irrigation schedulling, Water productivity
In the past, outcome of any water management strategy could only be known after field experiment, in recent times, means of evaluating the implications of irrigation schedules without field experiment is fast gaining grounds with the use of models. This research work present a scenarios studies for different developed irrigation scheduling options for a drip irrigated maize crop at the Institute for Agricultural Research (IAR) irrigation farm Samaru-Nigeria during 2013 and 2014 cropping season using a computer-based model. Aqua Crop was calibrated and validated with data obtained from the field, it was further used to generate scenario of different irrigation scheduling outcome. Grain and biomass yields, harvest index, seasonal evapotranspiration and crop water productivity were determined. The general trend of the results suggests that skipping regular irrigations may be advantageous if such is done at grain-filling stage, though most of the time this stage is intercepted by rain in the study area. The scenario studies showed that the peak grain and biomass yield value of 3273 and 10492 kgha-1 was recorded when 20 mm water application depth (WAD) with 3-day irrigation interval applied across all the growth stages; the irrigation water productivity with respect to grain and biomass yield were 0.83 and 2.65 kg m-3 respectively. The possible consequences of a developed irrigation scheduling on the crop and its environment, could be analysed without necessarily going to the field. The Aqua Crop model is useful for on-the-desk assessing of the impact of irrigation schedulling protocols.