Effect of Mulching and Manure Application Under Drip Irrigation on the Salinity Management and Watermelon ( Citrullus lanatus ) Productivity in Coastal Saline Soil

Salinisation is a major problem that impacts crop growth in coastal regions worldwide. This 4 years (2019–2020, 2020–2021, 2021–2022 and 2022–2023) study examined how mulching (plastic mulch, paddy straw mulch and no mulch) and organic manure (farmyard manure@15 t/ha, vermicomposting@5 t/ha, farmyard manure@7.5 t/ha + vermicomposting@2.5 t/ha and no manure) under drip irrigation can help to control salinity and improve the watermelon yield in coastal saline soils. The study was conducted in a factorial randomised block design with 12 treatment combinations which were replicated thrice. The pooled data showed that the plastic mulch along with farmyard manure and vermicomposting under drip irrigation was the best management practice for having maximum moisture (42.24%) and thereby reducing the salinity (0.99 dS/m) with slightly higher soil pH (7.11), resulting in maximum watermelon productivity. Principal Component Analysis revealed that PC1 described 77.60% of the total variations, with strong positive association between soil moisture, yield and negative relationship with salinity. The findings indicate that combining mulching with organic manure under drip irrigation is a practical and sustainable way to reduce salinity stress, conserve moisture and enhance watermelon production in salt‐affected coastal ecosystems.