Eshete Daniel G, Sinshaw Berhanu G, Gizaw Habtamu D, Zerihun Baye A
Department of Hydraulic and Water Resource Engineering, Insititute of Technology, University of Gondar, P.O. Box 196, Gondar, Ethiopia.
Amhara Region Agricultural Research Institute, Gondar Agricultural Research Center, Gondar, Ethiopia.
Sustain Water Resour Manag. 2022;8(6):186. doi: 10.1007/s40899-022-00771-5. Epub 2022 Oct 31.
Irrigation agriculture in Ethiopia can be improved by applying appropriate irrigation levels. Since water scarcity is the major problem in Ethiopia, and farmers apply water without knowledge of the amount of water to be applied, appropriate irrigation levels for maize crops should be investigated in the central Gondar zone, Ethiopia. This paper aims to investigate the effect of deficit levels of irrigation on crop parameters and evaluate the AquaCrop model for its predictability potential of water productivity. The experiment has four levels of water application (Full Irrigation (100%), 75%, 50%, and 25% of crop evapotranspiration) at 10 days of irrigation interval using Randomized Complete Block Design with three replications. Data collected in two experiments in the different seasons were soil moisture, canopy cover, biomass, and final yield. As high (0.93) and Nash-Sutcliffe Efficiency (NSE) (0.91) values indicated, the model performed well in simulating canopy cover, above-ground biomass, and yield in all treatments except 25% full irrigation (FI) with prolonged water deficit. Grain yield measured from experiment 2 was within the range of 4.6 t/ha to 7.4 t/ha. Even though a high yield was found from FI, the measured water use efficiency was better in 75% FI treatment, indicating a potential for water-saving by this treatment than FI. Higher grain yield was observed for maize sown in January at experiment 1. This was attributed to the rainfall impact on the experiment since it was spring season in Ethiopia at which some rainfall in the region is pronounced. In addition, AquaCrop thoroughly underestimated the seasonal evapotranspiration values and the deviations were commonly bigger as stress levels increased. Therefore, AquaCrop can be used in the simulation of crop parameters, prediction of irrigated outputs, and assessing the impact of irrigation scheduling.
通过采用适当的灌溉水平，可以改善埃塞俄比亚的灌溉农业。由于水资源短缺是埃塞俄比亚的主要问题，且农民在灌溉时并不清楚所需灌溉水量，因此应在埃塞俄比亚贡德尔中部地区研究玉米作物的适宜灌溉水平。本文旨在研究亏缺灌溉水平对作物参数的影响，并评估AquaCrop模型在预测水分生产率方面的潜力。试验采用随机完全区组设计，重复三次，灌溉间隔为10天，设置了四个灌溉水平（充分灌溉（100%）、75%、50%和25%的作物蒸散量）。在不同季节的两个试验中收集的数据包括土壤湿度、冠层覆盖度、生物量和最终产量。正如较高的（0.93）决定系数（R²）和纳什-萨特克利夫效率（NSE）（0.91）值所示，该模型在模拟所有处理（除了25%充分灌溉（FI）且长期缺水的处理）的冠层覆盖度、地上生物量和产量方面表现良好。试验2测得的谷物产量在4.6吨/公顷至7.4吨/公顷范围内。尽管充分灌溉处理获得了高产，但75%充分灌溉处理的实测水分利用效率更高，这表明该处理比充分灌溉处理具有节水潜力。试验1中1月份播种的玉米产量更高。这归因于降雨对试验的影响，因为当时是埃塞俄比亚的春季，该地区有一些明显降雨。此外，AquaCrop模型彻底低估了季节性蒸散量值，且随着胁迫水平的增加，偏差通常更大。因此，AquaCrop模型可用于模拟作物参数、预测灌溉产出以及评估灌溉调度的影响。
