Actual Crop Water Use in Project Countries : A Synthesis at the Regional Level

Wahaj, Robina ; Maraux, Florent ; Munoz, Giovanni

关键词: ACTUAL EVAPOTRANSPIRATION;    AGRICULTURAL DEVELOPMENT;    AGRICULTURAL PRODUCTION;    AGRICULTURE PRODUCTION;    ANIMALS;   

DOI  :  10.1596/1813-9450-4288
RP-ID  :  WPS4288

学科分类：社会科学、人文和艺术（综合）

来源: World Bank Open Knowledge Repository

【 摘 要 】

This report aims to synthesize theresults of a crop water use study conducted by country teamsof the GEF/World Bank project, Regional Climate, Water, andAgriculture: Impacts on and Adaptation of Agro-ecologicalSystems in Africa. It also presents the results of thesecond phase of the study based on climate change scenarios,conducted by the South Africa country team. The actualevapotranspiration of five commonly grown crops-maize,millet, sorghum, groundnuts, and beans-in two selecteddistricts were analyzed by six country teams. In addition,two country teams also analyzed other crops grown in thedistricts. The regional analysis shows that the actual yieldof the different crops-specifically of maize andgroundnuts-improves with an increase in actualevapotranspiration, although the gap remains wide betweenactual and potential yield and actual and maximumevapotranspiration, especially for the rainfed crops. Thishighlights the importance of improved water management ifagriculture is to play an important role as a source of foodsecurity and better livelihoods. The report highlights thevulnerability of maize to water stress and the increasedrisks to the viability of rainfed farming systems based onthis crop. The results of the second phase of analysis showthat a 2°C increase in the temperature and a doubling ofcarbon dioxide concentration in the atmosphere will shortenthe growing period of maize, which will result in decreasedcrop water requirement and use. The authors recommendextending this type of analysis to other crops as well as toother countries to develop a clearer picture of the changingpattern in crop water use of the major crops grown in theproject countries.