Optimizing Tomato Yield in Saline‐Sodic Soils With Gypsum and Mulching Techniques Near Lake Abaya, Ethiopia

The productivity of tomato fruit on the western shore of Lake Abaya in Ethiopia was severely hindered by saline‐sodic damage. This study aimed to assess the impact of applying gypsum and adopting soil mulching agricultural technology to improve the issues of salt‐affected soil in the region. The treatments consisted of a control group (T1), mulching (T2), gypsum application (T3), and a combination of gypsum (half level) and mulching (T4). Application rates of gypsum and straw mulching were 14.5 and 15 tons/ha, respectively. The mean total seasonal crop water consumptions of tomatoes were 378 mm (non‐mulching) and 333.02 mm (mulching). Straw mulching saved an average of 13.2% of soil water compared with non‐mulching treatments. At the end of the growing season, exchangeable sodium percentage was decreased by 42.3% (T2), 38.1% (T3), and 43.8% (T4) compared with control T1. The pH levels at the experimental site experienced reductions of 15.1% (T2), 1.1% (T3), and 14% (T4) compared with T1. The soil electric conductivity of the soil at the end of the tomato growing period was decreased by 59.6% (T2), 19.2% (T3), and 46.2% (T4). The average land productivity of tomatoes in the current study was 14.9 c tons/ha (T1), 16.2 b tons/ha (T2), 15.0 c tons/ha (T3), and 18.6 a tons/ha (T4). The average water productivity of tomatoes in the current study was 5.5 c kg/m 3 (T1), 7.2 b kg/m 3 (T2), 6.5 c kg/m 3 (T3), and 7.8 a kg/m 3 (T4). The benefit‐cost ratios for T1, T2, T3, and T4 were 1.67, 2.2, 1.78, and 2.4, respectively. The optimal strategy for mitigating saline‐sodic soil and ensuring sustainable tomato production involves applying gypsum at half the recommended level along with implementing straw mulching.