Potential for Diversifying Crops on Rice Monoculture Land Affected by Salinity Intrusion in the Mekong Delta

This study was conducted to evaluate the potential for crop diversification on rice monoculture land affected by salinity intrusion in the Mekong Delta. Data on current cropping practices were collected through interviews with over 204 households in Soc Trang Province during the 2022 dry season. Field experiments were carried out to assess the adaptability of selected cash crops such as beetroot, maize, and watermelon to drought and salinity conditions, as well as to evaluate their economic viability when cultivated as alternatives to rice in Long Phu and Tran De districts during the 2021–2023 dry seasons. The results indicated that in saline and drought-affected areas, more than 31 types of vegetables could potentially replace rice in the dry season. All three tested crops, beetroot, maize, and watermelon, demonstrated favorable adaptability and economic efficiency under saline and drought-affected conditions. Among them, beetroot yielded the highest economic returns, surpassing maize, watermelon, and traditional rice. These findings provide a scientific basic for local authorities and farmers to make informed decisions regarding the adoption of suitable cropping models to cope with regional drought and salinity challenges.