Farmers' Decision Making to Switch from Rice to More Adaptive and Profitable Systems in the Vietnamese Upper Mekong Delta

Abstract

<p>The Vietnamese Mekong Delta (VMD), a major Asian mega-delta, is known for its dynamic and productive interaction between human activities and natural processes. However, the dynamic processes and resources that render the VMD agriculturally rich also create vulnerabilities, exposing the region to various challenges including climate change impacts, salinity intrusion, land subsidence, rising sea levels and alterations in hydrological patterns. Rapid and fundamental changes in socio-economic, policy and market conditions simultaneously impact agricultural land use options and farm decision making. These factors threaten the Delta’s economic and environmental provisioning, necessitating both planned and autonomous adaptive strategies for sustainable development from both government and farmers. In the flood zone areas of the Upper VMD, flood-adaptive cropping patterns and flexible nature-based water management schemes are desired alternatives in order to reclaim the region’s former flood retention capacity, and to lessen the negative impacts on the environment caused by infrastructure development and agricultural intensification through high dyke systems and triple rice monocultures, respectively. Our study aimed to investigate which factors influence farmer decision making on crop choice and to understand how future cropping patterns (to 2030) align with the strategic directions indicated in national and local land use policies. </p> <p>We developed a stochastic spatio-temporal agent-based model (ABM) to simulate complex farmer decision making in an Upper VMD case study region. The ABM integrates various dynamic socio-economic and environmental factors in an expanded conceptual framework of the theory of planned behaviour and the Belief-Desire-Intention architecture. The model had three entities: farmer agents, spatial units, and a socioeconomic and biophysical environment (policy interventions, market price, and flood level). The model was run for 1,000 iterations on an annual time step over the 6 years from 2011 to 2016, and calibrated against 2016 data. Simulations were conducted for 2017-2030 under a Business-As-Usual (BAU) scenario and alternative scenarios at different flood levels and rice prices. Sensitivity analyses were conducted for key parameters (e.g. perception of environmental sustainability, knowledge of flood-based crops, financial capacity, labour requirement and risk preferences) to determine the robustness of the findings to changes in the modelled values and the key drivers of change.</p> <p>To link the ABM to contemporary policies in the region, a comprehensive policy review was conducted by screening and analysis of policy documents. This review focused on the post-1986 period when Vietnam introduced its Doi Moi economic reform policies, and on policy research papers related to agricultural development in the VMD. We also conducted semi-structured key informant interviews with experts and local officials, and five focus group discussions with a total of 50 farmers to refine the model inputs, verify and interpret the results. </p> <p>Revisiting the policies and the historic agricultural development in the VMD, we acknowledge the dynamic transformation associated with three policy periods. From 1970 to 1990s, the food-security focused policies promoting dyke construction and market liberalisation facilitated intensification of rice monocultures by expanding rice production area and increasing production intensity from two to three crops per year. From 2000-2017, there has been a gradual conversion from rice to other crops, driven by policies on agricultural structural change, which have sought to increase agricultural diversity, improve personal nutrition and boost exports of rice, fruit and aquatic products. Since 2017, after a long period focussing on maximising production volume, the Government shifted focus to quality of production, targeting high-value crops, value addition and sustainability in the VMD. In the flood zone of the Upper VMD, flood-based livelihoods and floodadaptive water management are particularly encouraged in order to lessen the negative impacts on the environment caused by widespread use of high dyke systems and triple rice monocultures. </p> <p>The results from the ABM, verified through stakeholders consultation, showed that further crop diversification will continue in the Upper VMD in the future and that the dominant trend is a transition from triple rice monocultures to fruit in the high dyke rings, whereas adoption rates of flood-based cropping systems will remain stagnant. This may lock the Upper VMD in to a rigid enclosed dyke system to protect fruit orchards as that land use becomes increasingly established. Such a hard-to-reverse situation will pose challenges for Government plans to periodically release floodwater into the fields. Our results highlight that the region will continue to face a number of overlapping trade-off dilemmas: (a) between pursuing greater economic outcomes or safeguarding ecological benefits at both the farm and landscape levels; (b) between farmers wanting flexibility in water management and possible cropping options, and those wanting flood water excluded to continue growing non-rice crops such as fruit; and (c) between policy (especially national policies) and actual on-farm land use practices. </p> <p>Farmer decision making plays a pivotal role in shaping cropping patterns and is influenced by multiple factors, either independently or through interactions among them. The model results showed the most dominant driving factors were biophysical (e.g. high dyke construction, natural and controlled floodwater levels) and socio-economic (e.g. risk preference, market price, market access, labour availability, pro-environmental perception and knowledge of new alternatives). Different factors exert varying degrees of influence on each crop choice. Particularly, level of risk-tolerance, the presence of high dykes, labour availability, market accessibility and low rice price significantly encourage the diversification of crops in place of traditional rice monocultures. Pro-environmental perception and knowledge of new alternatives considerably impact the adoption of low dyke crops and traditional flood-based crops, which are advocated by both the Government and scholars.</p> <p>Finally, we suggest that the phasing out of triple rice monocultures and high dyke cropping system can only occur gradually over a protracted period of time. Despite this, the Government should proactively implement a set of concrete and practical policy measures to realise its vision. These include: (i) increased bottom-up policy planning that explicitly considers the key determinants of farmer decision making; (ii) targeting smallholder rice farmers in high dyke areas and risk-averse farmers; (iii) innovative and flexible water management approaches that can regulate water in high dyke rings; (iv) research and innovation on mechanisation, flood-tolerant species and flood-adaptive farming techniques for both annual and perennial crops; (v) innovative extension activities to improve pro-environmental awareness and knowledge of alternative flood-based options; (vi) diversified risk management schemes; and (vii) value chain development. The lessons learned from the simulations and modelling techniques developed in this study for the VMD will be helpful for other mega-deltas facing similar challenges globally. Our results emphasise the need for holistic approaches that integrate environmental, social, and economic considerations to ensure long-term sustainability. </p>