Data_Sheet_1_Multi-Level Influences on Center-Pivot Irrigation Adoption in Alabama.docx

Rates of poverty and economic inequality in rural Alabama are among the nation's highest and increasing agricultural productivity can provide a needed boost to these communities. The transition from rain-fed to irrigation-fed (RFtoIF) agriculture has significantly increased farm productivity and profitability elsewhere in the United States. Despite this potential to enhance stability and resilience in rural economies, irrigated cropland accounts for only 5% of Alabama's total cropland as numerous barriers remain to irrigation adoption. To encourage RFtoIF transition, it is imperative to identify the challenges faced by individual farmers at farm, community, and state levels. This study presents a multi-level mixed effects survival analysis to identify the physiographic, socioecological, and economic factors that influence the location and timing of irrigation adoption. We integrate spatiotemporal cropland and climatological data with field-verified locations of center-pivot irrigation systems, local physiographic characteristics, and parcel-level surface water access and average well depth. Access to surface water, costs to access groundwater, and soil characteristics were generally important influences in all regions, but regions were differentiated by the extent to which new irrigation was more responsive to social influences vs. precipitation and price trends. Our findings also highlighted the diversity of farming conditions across the state, which suggested that diverse policy tools are needed that acknowledge the varying motivations and constraints faced by Alabama's farmers.

农村阿拉巴马州的贫困率和经济不平等程度位居全国之最，而提高农业生产率能为这些社区提供必要的助力。在美国其他地区，从雨养农业向灌溉农业（RFtoIF）的转型显著提升了农场生产力和盈利能力。尽管这一转型具有增强乡村经济稳定性和弹性的潜力，但灌溉农田仅占阿拉巴马州总耕地的5%，因为灌溉推广仍面临诸多障碍。为了鼓励RFtoIF转型，迫切需要识别个体农民在农场、社区和州级层面所面临的挑战。本研究提出了一种多级混合效应生存分析，以识别影响灌溉采用地点和时机的水文地理、社会生态和经济因素。我们将时空耕作土地和气候数据与经现场验证的中心旋转灌溉系统位置、地方水文地理特征以及地块级别的地表水获取和平均井深进行整合。地表水获取、获取地下水的成本以及土壤特性在所有地区都普遍是重要的影响因素，但各地区在新的灌溉措施对社会责任影响与降水和价格趋势的响应程度方面存在差异。我们的研究还突出了该州农业条件的多样性，这表明需要多样化的政策工具，这些工具应承认阿拉巴马州农民所面临的动机和约束的差异。