Theriault Veronique, Smale Melinda, Haider Hamza
Department of Agriculture, Food and Resource Economics, Michigan State University, East Lansing, MI 48824, USA.
Food Secur. 2018;10:1263-1277. doi: 10.1007/s12571-018-0842-z. Epub 2018 Sep 15.
Increasing agricultural productivity while protecting natural resources depends on proper understanding of farmers' incentives to use intensification strategies, including fertilizer. Using a large-scale household dataset collected in rural Burkina Faso, we examined how the response of maize yield to fertilizer, and thus the economic incentives for its use, varied according to agro-ecological conditions. We employed a Control Function Approach with Correlated Random Effects in order to test and control for endogeneity of fertilizer use, measuring agro-ecological conditions at several scales. We investigated the profitability of fertilizer use with value-cost ratios. We found that productivity and marginal effects of fertilizer differ significantly according to agro-ecological conditions. Micro-variation appeared to be more critical than the definition of agro-ecological zone. Burkinabe soils are severely degraded and would benefit from greater application of fertilizer. However, at full market prices, fertilizer use was unprofitable. Though it was profitable with subsidized prices, transaction costs diminish the benefits of the subsidy. Profitability of fertilizer use with maize varied across agro-ecological conditions, even for field plots located in the same agro-ecological zone. Our results confirm that policy makers need to be cautious when generalizing across regions or drawing policy recommendations from a single agro-ecological zone because crop responses and economic incentives vary widely.
在提高农业生产力的同时保护自然资源，取决于对农民采用集约化策略（包括使用化肥）动机的正确理解。利用在布基纳法索农村收集的大规模家庭数据集，我们研究了玉米产量对化肥的反应，以及因此使用化肥的经济激励如何因农业生态条件而异。我们采用了具有相关随机效应的控制函数方法，以测试和控制化肥使用的内生性，并在多个尺度上衡量农业生态条件。我们用价值成本比来研究化肥使用的盈利能力。我们发现，化肥的生产力和边际效应因农业生态条件而异。微观变化似乎比农业生态区的定义更为关键。布基纳法索的土壤严重退化，需要更多地施用化肥。然而，按全市场价格计算，使用化肥无利可图。虽然在补贴价格下使用化肥有利可图，但交易成本降低了补贴的效益。即使是位于同一农业生态区的地块，使用化肥种植玉米的盈利能力也因农业生态条件而异。我们的研究结果证实，政策制定者在跨地区推广或从单一农业生态区得出政策建议时需要谨慎，因为作物反应和经济激励差异很大。
