Salt-affected soils are a prevalent issue globally, resulting in a severe degradation of soil sustainability and plant productivity, reducing the area of agricultural land, and affecting food security. Therefore, eco-solutions and remediation approaches are needed. The needed remediation for salt-affected soil can be addressed via engineering, physical, chemical, or biological techniques. Salt-tolerant crops are normally used for the remediation of slight and moderate saline soil conditions. However, no crops, including salt-tolerant crops, can be cultivated in areas with extreme salinity levels (ECe 8–16 dS/m). Therefore, the aim of this study was to investigate the effect of vermicompost and organic amendment on the cultivation of salt-tolerant crops (Sesbania rostrata) in severely salt-affected soil under field conditions in order to improve saline soil and crop productivity. The design of the experiment followed a randomized complete block design (RCBD) with three treatments and four replications: T1, severely salt-affected soil (control); T2, severely salt-affected soil + vermicompost at a ratio of 25:75; T3, severely salt-affected soil + vermicompost + rice husk biochar + coconut coir at a ratio of 25:25:25:25. The results found that using vermicompost and organic amendment improved the soil quality, increased the soil fertility (organic matter and plant nutrients N, P, and K), and reduced the soil salinity. Sesbania rostrate could not grow in severely salt-affected soil (T1) alone, but could grow in the treatments with vermicompost and organic amendments (T2 and T3). The percentage of Sesbania survival per plot was also high in the treatments with vermicompost and organic amendments (T2 and T3). The highest growth rate, flower production, biomass, and root morphology of Sesbania rostrata were found in T3, with severely salt-affected soil + vermicompost + rice husk biochar + coconut coir at a ratio of 25:25:25:25 with a statistically significant difference (p < 0.05). Moreover, the Sesbania flowers treated with vermicompost and organic amendments have a higher nutritional value due to their minerals and vitamins than Sesbania flowers grown without using vermicompost and organic amendments. This study’s findings suggest that incorporating vermicompost and organic amendments is a feasible and economical method for enhancing the quality of salt-affected soils in a sustainable manner. The results of this study demonstrate that utilizing vermicompost and organic amendments is a sustainable and economical strategy for enhancing the quality of salt-affected soils and improving yields in severely salt-affected areas, thereby increasing crop production and the nutritional value of the plants as well as helping to increase farmers’ income.

Groundwater-dependent irrigated agriculture in semi-arid basins is increasingly threatened by climate variability and aquifer depletion. Karapınar district, located within Türkiye’s Konya Closed Basin, represents a water-stressed melon-producing area where deep-well drip irrigation and rigid calendar-based scheduling remain common. This study developed a prototype AquaCrop-based decision-support framework for adapting mature and pickled melon irrigation to climatic conditions classified by the crop-season weighted three-month Standardized Precipitation Index (SPI-3). SPI-3 was selected to represent short-term seasonal precipitation anomalies relevant to agricultural water availability, and three historical years were used as representative scenarios: Dry (2020), Normal (2018), and Wet (2017). Fourteen irrigation treatments, including farmer practice and phenologically targeted Late-Season Event (L.S.E.) deficit strategies, were simulated using FAO AquaCrop v7.1. Irrigation timing was more important than seasonal irrigation volume alone. Under Normal conditions, an L.S.E. strategy that redistributed irrigation toward four late fruit-development events (T4.2) maintained yield stability comparable to farmer practice (CV < 2%), increased mature melon yield by 12.7% relative to farmer practice, and reduced applied irrigation by 19–21%. Under Dry conditions, a lower-volume L.S.E. strategy with the same late-season targeting (T4.3) maintained baseline-level yield while reducing applied irrigation by 28–31%. The resulting SPI-based decision matrix is forecast-compatible but not operationally validated; field validation, long-term climate testing, and forecast-skill evaluation remain necessary before deployment.