Assessment of the Impact of Temperature and Rainfall on Sorghum Yield Under Semi-Mechanized Rain-fed Subsector in Gedarif State, Sudan

تقييم تأثير درجة الحرارة وهطول الأمطار على إنتاجية الذرة الرفيعة في القطاع شبه الميكانيكي المطري بولاية القضارف، السودان

Abstract

This study aimed to monitor climatic factors trends such as annual rainfall, minimum and maximum monthly temperatures during 1971-2015, and to assess the impacts of these factors on sorghum yield under semi-mechanized rainfed subsector in the Gedarif state. Data from secondary sources was used in this study. Climate data included annual rainfall, average of monthly maximum and minimum temperatures obtained from Sudan Meteorological Authority (SMA). Production data included time series data of sorghum yield was obtained from Ministry of Agriculture and Forestry, statistics division, Khartoum Sudan, and Gedarif State Ministry of Agriculture, Information Centre, Gedarif, Sudan. Correlation, trend analysis and multiple regression were the main analytical tools used in this study. Correlation coefficients results showed negative and highly significant (P<0.01) relationship between sorghum yield and temperatures (maximum and minimum), as well as positive but insignificant relationship between sorghum yield and annual rainfall. These facts explain that, Gedarif state is affected by climate change. Results of multi regression coincides with correlation results for annual rainfall, this implies that, other factors beside the climate affect semi-mechanized rainfed sorghum production such as lack of herbicide and fertilizer applications, and lack of a proper crop rotation. The study concluded that variation in annual rainfall and increased maximum temperatures as a result of climate change during the last five decades has negatively affected sorghum yield in the semi-mechanized rainfed subsector of the Gedarif state. To mitigate the effects of climate change, the study recommended to introduced short maturing cultivars of sorghum, besides the use of Zero tillage (ZT), which is based on the concept of direct seeding without plowing or harrowing and using of chemicals for weed control. Thus, the production costs would be decreased, beside increase sorghum yield.