Dynamic Adaptation and Crop Abandonment under Prolonged Drought in Semi-Arid Regions

Water scarcity is a growing global challenge that threatens agricultural sustainability, food security, and the livelihoods of rural communities. Agriculture accounts for approximately 70–80% of global freshwater withdrawals, making it particularly vulnerable to declining water availability driven by climate change, population growth, and competing demand.

Perennial crops face specific challenges under water scarcity due to their long investment horizons, high establishment costs, and limited flexibility in land reallocation. Unlike annual crops, perennial orchards are dynamic systems that are influenced by both short-term and cumulative conditions, which impact both production yields and overall tree performance. As a result, farmers’ behavioral responses to water scarcity differ markedly between perennial and annual systems, where most of the literature has focused.

This study examines farmers’ dynamic decisions in perennial crop systems and the factors influencing changes in cultivated areas and crop abandonment in drought-prone contexts. Our case study is situated in a semi-arid region of Central Chile, where a three-decade decline in precipitation and a persistent megadrought since 2010 have resulted in reduced river flows, declining groundwater levels, intensified water competition, and significant land-use changes. In parallel, early in the decade, the region saw a shift toward permanent, high-value, and export-oriented crops—such as avocados, walnuts, and citrus—displacing annual production and livestock, reshaping the agricultural landscape, and the demand for water.

To analyze farmers' decisions, we use data from a novel survey of 200 farmers from the Ligua-Petorca basins, which incorporates retrospective recall of past production outcomes to address dynamic decision-making processes. This approach allows the reconstruction of farmers’ past responses to water scarcity. Following various econometric approaches, which combine panel data models and limited dependent variable regressions, we find substantial heterogeneity in adaptation responses across farmers. Changes in cultivated areas are systematically associated with farm size, access to surface water, crop type, and the characteristics of farmers. Also, expected climatic conditions, proxied by recent trends, are found to influence crop area changes and abandonment.

This research sheds light on the understanding of how farmers adapt to prolonged droughts in perennial production systems, an understudied topic in the literature but evermore relevant in the context of a changing climate. The proposed methodology enables addressing this issue in contexts where recurrent surveys are uncommon, such as in many semi-arid regions of lower-income countries. While recall-based data cannot replace true longitudinal panels, their use provides a feasible alternative for examining adaptation and abandonment processes in such environments, thereby expanding the empirical tools available for studying long-term agricultural responses to drought. Ignoring the differences between permanent crops and annuals implies overlooking the dynamic nature of perennial systems, misdiagnosing farmers’ constraints, and overestimating their flexibility. Observed reductions in cultivated area under prolonged water deficits are consistent with crop abandonment becoming a relevant outcome when adaptation pathways are limited in perennial systems. Recognizing these differences is essential for advancing research on agricultural adaptation and for informing the design of effective water and agricultural policies tailored to perennial systems under drought conditions.