Tropentag 2022, September 14 - 16, Prague, Germany "Can agroecological farming feed the world? Farmers' and academia's views."

Agro-ecological water and crop management practices’ effect on rice yield and water productivity in lowlands: a meta-analysis

¹University of Parakou, Hydraulics and Environmental Modelling Laboratory, Benin
²Université Catholique de Louvain, Earth and Life Institute, Belgium

Abstract

Climate variability frequently leads to water scarcity in agriculture in general and rice growing in particular. There are many adaptation techniques developed for rice cultivation by diversifying production environments and increasing water management practices. Nevertheless, little is known about their performances. This meta-analysis aims to evaluate the crop management performances of various water management practices in lowland rice cultivation worldwide. We conducted research using Scopus and web of science databases with the keywords << irrigation AND "water productivity" OR "water use efficiency" AND rice* or paddy AND lowlands OR plains OR "inland valley" >>. The criteria applied are essentially the language (English or French), the year (2000-2021), and the type of document (peer-reviewed papers). A total of 56 articles out of 441 met these criteria, from which 573 Observations were collected. Five (05) water management practices were identified in lowland rice as follows: Continuous Flooding (CF), Saturated Soil (SS), moderate Alternative Wetting and Dry (AWDm), severe Alternative Wetting and Dry (AWDs), and Aerobic rice (AR). We compared SS, AWDm, AWDs, and AR practices to CF. The response ratio of the yield and water productivity (RR) were used as measures of the effect sizes of the response of water stress on rice yield and water productivity. Our study revealed that yields decreased by 11.1 % and 37.5 % respectively in the AWDs and Aerobic systems compared to CF. While on saturated and AWDm practices, the differences in performance compared to CF are not significant (P> 0.05). Water productivity increased by 25.7 %, 32.9 %, and 25.6 % under AWDm, AWDs, and Aerobic systems, respectively. Findings also showed that rice yield and water productivity were significantly improved with rice short genotype cycle, in' direct sowing under AR practices and higher plant density (]75;100]). Meanwhile, the best water productivity (49 %) was observed under AWDs system when rice is transplanted with plant density 25 plants m². The implementation of the AWDm practices allowed to improve water productivity by 25.7 %, while maintaining rice yield.

Keywords: Aerobic rice, agroecological water management practices, alternative wetting, and dry, continuous flooding, rice, soil saturation

Contact Address: Bio Zime Sounon Orou, University of Parakou, Hydraulics and Environmental Modelling Laboratory (HydroModE-Lab), Parakou, Benin, e-mail: biozimsounonyahoo.com