Data_Sheet_1_A Public-Private Partnership to Locate Fields for Implementation and Monitoring of Best Management Practices to Treat Legacy Phosphorus.pdf

Legacy nutrients stored in agricultural soils are a substantial component of riverine nutrient discharge contributing to the eutrophication of aquatic ecosystems. These nutrient loads can persist and delay water quality initiatives, for example, those of the Great Lakes Water Quality Agreement which seek to reduce phosphorus (P) loads entering the Western Lake Erie Basin. In this watershed, approximately 5% of fields have P concentrations 2.5-fold greater than the maximum agronomic recommendations for corn and soybeans. Fields with these elevated-P concentrations (>100 mg P kg−1 soil) act as a source of legacy-P and discharge greater P loads. Implementing best management practices to treat runoff from these fields is desirable but finding them has been a challenge as soil test data are proprietary information creating an asymmetric information barrier. To overcome this barrier, we formed a public-private partnership that included agricultural retailers who conduct soil testing for farmers. Agricultural retailers who partnered with this project provided their soil P data and contacted farmers to gauge their interest, maintaining privacy for farmers until they expressed interest. Only 3.8% of soil samples in the provided data had elevated-P concentrations. In many cases, these elevated-P soils were confined to zones within fields, and 13% of fields had at least one elevated-P zone. We pursued these elevated-P fields as research sites for the implementation and monitoring of management practices. The agricultural retailers contacted 77 farmers with surveys, and 25 responded with interest in meeting the research team to discuss the project. Following a preliminary evaluation with the spatial data of fields operated by interested farmers, visits were arranged so that 12 research sites could be located. As indicated through the surveys, discussions with farmers, and soil data, many of the fields had accumulated elevated-P due to historic land-use (livestock, manure, or biosolid application) creating legacy sources. We conclude that public-private partnerships featuring agricultural retailers are a promising tool that may help overcome asymmetric information barriers to finding and managing agricultural fields with legacy-P that that disproportionately contribute to nutrient runoff.

在农业土壤中储存的陈旧养分是河流养分排放的重要组成部分，这导致水体生态系统的富营养化。这些养分负荷可能持续存在并延缓水质改善措施的实施，例如《五大湖区水质协定》，该协定旨在减少进入西方伊利湖盆的磷（P）负荷。在该流域中，约5%的田地磷浓度超过玉米和大豆最大农学推荐量的2.5倍。这些高磷浓度（>100 mg P kg−1 土壤）的田地作为陈旧磷源，排放出更多的磷负荷。实施最佳管理实践以处理这些田地的径流是有益的，但寻找这些田地一直是一项挑战，因为土壤测试数据是专有信息，形成了一种信息不对称的障碍。为了克服这一障碍，我们建立了一个包括为农民进行土壤测试的农业零售商在内的公私合作伙伴关系。与该项目合作的农业零售商提供了他们的土壤磷数据，并联系农民以了解他们的兴趣，在农民表达兴趣之前保持农民隐私。在提供的数据中，仅有3.8%的土壤样本存在高磷浓度。在许多情况下，这些高磷土壤局限于田地内的特定区域，13%的田地至少有一个高磷区域。我们将这些高磷田地作为实施和监测管理措施的研究基地。农业零售商通过调查联系了77位农民，其中25位表示有兴趣与研究团队会面讨论项目。在对感兴趣农民经营田地的空间数据进行初步评估后，安排了访问，以确定12个研究地点。如调查、与农民的讨论和土壤数据所示，许多田地由于历史上的土地利用（如牲畜、粪便或生物固体应用）而积累了高磷，形成了陈旧来源。我们得出结论，具有农业零售商参与的公私合作伙伴关系是一种有前景的工具，可能有助于克服发现和管理对养分径流贡献不均的农业高磷田地的信息不对称障碍。