Intensive and extensive margin adjustments to water scarcity in France's Cereal Belt
研究法国博斯地区农民应对水资源短缺的三种调整方式：转向雨养农业、改种低耗水作物和减少灌溉强度，发现转向雨养农业贡献了57%的调整效果。
Efficient water management in agriculture is becoming critical due to increasing environmental constraints and global food and bio-energy demands. Farmers may respond to increased water scarcity along three main adjustment margins: a move towards rain-fed agriculture (super-extensive margin) or towards less water-intensive crops (extensive margin), and a reduction in water intensity for irrigated crops (intensive margin). Using a positive mathematical programming model of regional supply calibrated to economic and agronomic information, we decompose the total effect of reduced water availability on these adjustment margins in Beauce, a productive cereal region that relies on a groundwater resource to meet its irrigation needs. For realistic water scarcity scenarios, 57 per cent of the total response is attributable to super-extensive margin adjustments. The extensive margin represents 28 per cent of the total response, while the intensive margin accounts for 15 per cent. Crop-level analysis reveals more subtle adaptation patterns.