Past trajectories, current preferences, and alternative futures for the sustainable intensification of coastal farming systems in Bangladesh

Agricultural systems in southern coastal regions of Bangladesh are underdeveloped compared to the rest of the country. Agriculture is mainly rainfed with lower cropping intensities in these areas. The northern part of the country on the other hand grows a number of crops including rice, wheat, potato and maize during the dry winter season by groundwater irrigation. While the agricultural development in Southern Bangladesh was dependent on rainfall, the northern Bangladesh exploited groundwater for irrigation. Both these approaches remain unsustainable because rainfed agriculture has resulted in lower cropping intensities, while the increased withdrawal of groundwater for irrigation has led to declining groundwater tables, high pumping costs, and exorbitant energy subsidies. Whereas groundwater irrigation is unsustainable, agriculture in Bangladesh can make use of surface water irrigation (SWI) as the country has a dense network of rivers and natural canals. Especially in the Southern coastal regions, which is part of the Ganga-Meghna-Brahmaputra River Basin and the associated tidal ecosystem can be efficiently tapped for surface water irrigation. Nonetheless, most projects aimed at agricultural intensification through SWI have not attained the desired potential due to poor management and lower capacity of farmers to invest in irrigation or buying irrigation service provision. With a projected population increase to 200 million by 2050, ensuring national food security in the face of these obstacles will require, among others, the adoption of sustainable agricultural practices, alongside sustainable management of natural resources including land and water upon which agricultural production is dependent. In Bangladesh today, old and new models of intensification are being considered for implementation.In Southern coastal Bangladesh, farmers often fallow their land or grow low-input ‘opportunity’ crops during the dry rabi season, following monsoon season rice. In 2018, the Government of Bangladesh (GoB) has launched the Bangladesh Delta Plan 2100 (BDP 2100) with an investment plan of USD 37 billion to address development challenges. A major share of which is intended to facilitate sustainable agricultural transformation of coastal districts. At the farm level, approaches are loosely based on sustainable intensification (SI), which aims to conserve natural resources while sustainably boosting productivity and improving social equity.Many agricultural interventions in coastal Bangladesh however focus on agronomic management packages and irrigated dry season rice to replace fallows and rainfed agriculture, with less attention to other cereals and legumes, or other components of farmers’ whole farm production systems. The degree to which these development interventions are successful is ultimately conditioned by individual farmers’ preferences and decisions and farmers’ participation but these are not well understood. Changes in crop and farm management also require farmers to invest time, money, and labour, which can be risky, especially in socially and environmentally vulnerable agro-ecosystems. Taking coastal Bangladesh as a case study, the research presented in this thesis addresses knowledge gaps with respect to (1) understanding the evolutionary “past” of farming systems trajectories and changing cropland use (e.g., directionality, drivers, and impacts) from a sustainable intensification perspective, (2) understanding farmers “present” knowledge of their farming system with respect to drivers of food security and cropping intensification, and (3) explore farmers’ decision-making processes, crop preferences, risk attitude, and investment choices in irrigation as an SI pathway, that is intended to (4) design farming systems incorporating “future” preferences.Research followed the interdisciplinary DEED approach: (1. Describe) Existing longitudinal data compilation and farm surveys were implemented to collect relevant agronomic, socio-economic, and natural resources management data from farmers. This information was used to identify farm typologies and analyse trajectories of historical land use intensity change. (2. Explain) an in-depth analysis and mental of farmers’ cognition of their farming systems and opportunities associated with intensification were conducted for sub-sets of identified farm types, using fuzzy cognitive mapping (FCM). (3. Explore) Choice experiments (CEs) were implemented to explore farmers preference for cropping intensification and their willingness to invest in irrigation and fertilizers. (4. Design) Results from CEs were used to design alternative systems using farm modelling and trade-off analysis, thereby providing insights for plausible intensification pathways for different farm types.The Chapter 1 provides a general introduction and overall outline of the thesis. Chapter 2 characterizes the coastal farming system and the social-ecological change through a comprehensive driver-response reconstruction in the study area. Multi-level socioecological factors, i.e., micro-level (fragmentation of landholdings, mechanisation, farmers experience, salinity, soil condition); meso-level (market status, tenure, labour availability, access to extension) and macro-level (density of population and cyclone incidence) were found to influence the farm type changes in the study area. These results formed the basis for chapters 3 and 4. Chapter 3 describes the FCM methodology to understand how farmers in coastal Bangladesh cognize constraints, and opportunities associated with crop intensification options.The perceived differences in understanding of farming systems from farmer to farmer or among different types of farms possibly due to the heterogeneity of socio-economic characteristics or behaviour of the farmers were investigated and presented in this chapter.In Chapter 4 farmers’ preferences of alternative cropping options for fallow land replacement with alternative irrigated and non-irrigated crops during the dry season was investigated through choice experiment (CE). This chapter also presents the results of the analysis on whether farmers’ preferences are conditioned by investment requirements on input use (with emphasis on irrigation and fertiliser) and/or expected net revenues. Chapter 5 presents the different trade-offs among multiple objectives in respect to profits, organic matter balance, labour and GHG emissions, alongside simulations of alternative sustainable intensification solutions.Chapter 6 presents the general discussion on the main findings of the thesis. By analysing the farm trajectories over the past twenty years, the thesis showed the trend in coastal Bangladesh of a shift of heterogeneous, rice-livestock farms to more homogenous farms with off-farm income. The findings in this thesis also emphasizes the importance of farmer roles in agricultural policy towards the intensification of agriculture in coastal Bangladesh, and the need to address farmers' cropping preferences, alongside their sensitivities to institutional interventions, i.e., ensuring access and availability of extension and micro-credit