University of Twente Student Theses
The analysis of the agricultural crop water productivity behaviours in semi-arid and humid regions for irrigated and rainfed areas, case studies Sudan and Rwanda
Ndikubwimana, Innocent (2021) The analysis of the agricultural crop water productivity behaviours in semi-arid and humid regions for irrigated and rainfed areas, case studies Sudan and Rwanda.
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Abstract: | The agricultural water demand is increasing in semi-arid and humid regions. Agricultural water use efficiency is key to monitor and improve crop water productivity in changing climate. The arid or semi-arid regions face water scarcity problems. The objective of this research is to analyse crop water productivity behaviour in semi-arid and humid climates using the Gezira irrigation scheme of Sudan and Nasho irrigation scheme of Rwanda as semi-arid and humid regions, respectively. The research aim was achieved by quantifying, analysing, and comparing the crop water use indicators such as transpiration, evapotranspiration, biomass production, and gross crop water productivity in both semi-arid and humid climates for a period of three years from 2018 to 2020. For the Gezira irrigation scheme, the results show the average seasonal transpiration values of 402, 322, and 713 mm/season for groundnut, sorghum, and cotton (both summer and winter) for the summer season and 395, 415, and 434 mm/season for onion, pigeon pea and wheat, respectively for the winter season. While average seasonal evapotranspiration of 564, 496, and 965 mm/season are obtained for groundnut, sorghum, and cotton (summer and winter), respectively for the summer season and 491, 517, and 540 mm/season for onion, pigeon pea, and wheat, respectively for the winter season. The overall average seasonal TBP are 2991, 2148 and 6359 kgDM/ha/season for groundnut, sorghum, and cotton, summer crops and 3225, 3246, and 3094 kgDM/ha/season for onion, pigeon pea and wheat as winter crops. While average seasonal gross crop water productivity values are 0.56, 0.43 and 1.96 kg/m3 for groundnut, sorghum, and cotton, summer crops and 0.73, 0.77, and 0.76 kg/m3 for onion, pigeon pea and wheat, respectively as winter crops. For Nasho irrigation scheme, the results show the average seasonal transpiration values of 306 and 323 mm/season for beans and maize for the summer season and 364 and 420 mm/season for beans and maize, respectively for the winter season. While average seasonal evapotranspiration of 399 and 415 mm/season for beans and maize are obtained for the summer season and 493 and 538 mm/season for beans and maize, respectively for the winter season. The average seasonal TBP of 10534 and 11169 kgDM/ha/season for beans and maize as summer crops and 12440 and 13349 kgDM/ha/season for beans and maize as winter crops. Also, gross crop water productivity of 2.67 and 2.70 kg/m3 for beans and maize, summer crops and 2.50 and 2.43 kg/m3 for beans and maize as winter crops are obtained. Comparative analysis of crop water consumption between semi-arid and humid climates finds the higher values of evapotranspiration for semi-arid climate compared to the humid climate in the summer season but both climates have almost the same values in the winter season. Climate normalisation of crop water productivity approach was tested for groundnut, pigeon pea, sorghum, and wheat for semi-arid climate and for irrigated beans and maize of humid climate during summer and winter seasons. For semi-arid climate, the average values of CWP and CWPc are 0.57, 0.4 and 0.99, 0.62 kg/m3 for groundnut and sorghum, respectively and 0.77, 0.6 and 1.42, 1.46 kg/m3 for pigeon pea and wheat, respectively were obtained. For humid climate, the 2.5 and 3,2 kg/m3 of CWP and CWPc for winter beans and 3.0 and 3.0 kg/m3 of CWP and CWPc for summer beans were found. Also 2.7 and 2.0 kg/m3 of CWP and CWPc for summer maize and 2.4 and 2.4 kg/m3 of CWP and CWPc for winter maize. The study concludes that semi-arid climate crops are more affected by climate constraints than humid climate crops, especially for winter seasons. In both climates, the C3 crops are more affected than the C4 crops. This study also concludes that the Climate normalisation of the CWP approach can help at regional scale to evaluate the spatial variability of crop water productivity gaps within the irrigation schemes, especially in arid and semi-arid climates where the agricultural crops are highly affected by the climate constraints. |
Item Type: | Essay (Master) |
Faculty: | ITC: Faculty of Geo-information Science and Earth Observation |
Programme: | Geo-informatics MSc (60031) |
Link to this item: | https://purl.utwente.nl/essays/88997 |
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