Response of sorghum [ <i>Sorghum bicolor</i> (L.) Moench] genotypes to climate smart practices for agronomic performance and water use efficiency in the Southern Province of Rwanda

Climate change causes soil water deficit, which limits the production of sorghum, a crucial crop for smallholder farmers in Rwanda. Therefore, a study was conducted in Rwanda to assess the response of sorghum genotypes to climate smart practices for water use efficiency, growth, soil water content, yield and components. The experiment was set up in a split plot design at Rubona and Mututu, with three replications. The treatments included three climate smart practices (close tied ridging, mulching, and zai pits) and a conventional practice in the main plot, and seven genotypes (Gihove, Nyirakinuma, Gatemwa, Nyiragikori, Nyiragahengeri, Umuceri, and Kigufi) in the sub plot. The results showed that all evaluated parameters were significantly affected by the interaction between genotypes and climate smart practices. The interaction between mulching and Nyiragahengeri resulted in the highest water use efficiency (7.23 kg ha−1 mm−1 at Rubona and 7.78 kg ha−1 mm−1 at Mututu) and the highest grain yield (3664.00 kg ha−1 at Rubona and 3322.22 kg ha−1 at Mututu). Mulching performed better in maintaining soil water content compared to tied ridging and zai pits. The study concluded that the combinations of mulching and Nyiragahengeri, close tied ridging and Gihove are recommended for high grain yield in Rubona water limited conditions, while mulching and Nyiragahengeri, tied ridging and Nyiragahengeri would be ideal in Mututu more water stressed conditions. The study highlights the importance of combining appropriate climate smart practices with responsive genotypes. This will increase sorghum yield and improve the livelihood of sorghum farmers in Rwanda.