[01] Hussien Elshareef Elamin, Department of Agricultural Engineering, Faculty of Agriculture, University of Khartoum, Khartoum, Sudan. [02] Abdelmoneim Elamin Mohamed, Department of Agricultural Engineering, Faculty of Agriculture, University of Khartoum, Khartoum, Sudan. [03] Amir Mustafa Abdeldaim, Department of Agricultural Engineering, Faculty of Agriculture, University of Khartoum, Khartoum, Sudan.

This study was carried out to assess the climate change impact on crop water requirement (ETc) of the main fodder crops grown in Khartoum State, Alfalfa and Sorghum (Abu-Sabeen). Daily meteorological data for the period 1988-2017 were collected from Sudan Meteorological Authority (SMA); temperature, humidity, wind speed, sunshine hours and rainfall data. Reference evapotranspiration (ETo) was determined using mean monthly meteorological data with help of CROPWAT 8.0 software package, which uses the FAO Penman-Monteith procedure and then crop water requirement (ETc) was determined. Statistical Analysis System Software (SAS) was used to analyze the data. The results indicated decreasing trends in relative humidity (RH%) and the opposite holds true for temperature and wind speed, with marked fluctuations in rainfall. Accordingly, ETo (mm/day) increased by 23%, ETc increased by 64% for Alfalfa of the second cutting (1734 m³/ha in 1988 and 2845 m³/ha in 2017), 26% for Abu-Sabeen forage (4935 m³/ha in 1988 and 6212 m³/ha in 2017). It was concluded that ETo values were significuntly (P ≤ 0.05) different, ETc followed the same trend of ETo and in the rainy seasons irrigation requirements were affected by effective rain. Results showed rising demand of water requirement for fodder crops from 1988 to 2017 due to climate change – decrease in RH%, increase in temperature and wind speed and fluctuations in rainfall. The study recommends taking in consideration the impact of climate change in supplying irrigation water for forage crops and irrigation management according to the growth stage of the crop and season.

Climate Change, CROPWAT 8.0, SAS, ETo, ETc, Crop Irrigation Requirement

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