Determinants of Crop Diversification in Boro Rice-Based, Wetland Farming Systems in Bangladesh

The haor landscape of Bangladesh is highly reliant on Boro rice cultivation, making farm households vulnerable to recurring floods and climate-related risks. Crop diversification can intensify agricultural resilience and reduce production risks. This study examined the pattern, extent, and determinants of crop diversification using a cross-sectional field survey performed in 2023 among 240 farm households in three purposively selected upazilas (Itna, Mithamoin, and Nikli) of Kishoreganj district. The Simpson Diversification Index (SDI), based on crop-area shares, was used to measure crop diversification, while Censored Tobit and Ordered Probit models were employed to identify its determinants. The results showed that farmers were gradually familiarizing themselves with crops such as maize, mustard, jute, chili, sweet potato, groundnut, potato, pumpkin, black gram, and various vegetables, along with Boro rice. The mean SDI was 0.22, with 58.33% of households falling within the poor diversification category (0-0.24). The Tobit model indicated that household head education, farm size, agricultural training, marketing training, and extension contact positively associated with crop diversification. In contrast, road distance, duration of waterlogging, and agro-ecological location had negative effects. The Ordered Probit results generally confirmed these associations and also revealed a positive relationship between the dependency ratio and the higher category of crop diversification. Marginal effects indicated that agricultural training, marketing training, and extension contact increased the probability of achieving excellent diversification by 6.2, 5.5, and 4.8 percentage points, respectively, while each additional kilometer from a nearby road and each additional month of waterlogging reduced this probability by 5.4 and 3.1 percentage points, respectively. These findings emphasize the importance of improving farmer training, extension services, rural infrastructure, and location-specific waterlogging control to increase crop diversification and resilience in haor farming systems. Given the purposive selection of three upazilas in Kishoreganj district, the findings should be interpreted with caution in other haor regions.