Farming adaptation to environmental change in coastal Bangladesh: shrimp culture versus crop diversification

摘要

Fanning in coastal Bangladesh includes rice/shrimp and riceon-rice cropping systems. The former has been highly profitable but has exacerbated salinization of soil and water. We evaluate the relative profitability, riskiness, and sustainability of the two cropping systems, using data from two coastal villages in Khulna District. Shrimp cultivation was initially very rewarding. However, over 12-15 years, the cropping system experienced declining profitability, increased salinity, and adverse impacts on rice cropping and the local environment. From 2009, farmers adapted the system by changing the pond (gher) infrastructure, adopting delayed planting of a saline-tolerant rice cultivar, flushing out accumulated salt with freshwater during rice cropping, and allowing the soil to dry out after harvesting rice. The budgeting results show that with current management practices, the rice/shrimp system is economically more viable (higher returns to land and labour and less risky) than the riceon-rice system. Soil analyses showed that while salinity was higher in the gher during the dry season, it was significantly reduced in the wet season and was very similar between the two systems (1-2 dS/m). Hence, as well as being more profitable and less risky, the rice/shrimp system may well be more sustainable than previously observed.