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Evaluating Management Implications of the New York Phosphorus Index with Farm Field Information
Author(s) -
Ros Mart B. H.,
Ketterings Quirine M.,
Cela Sebastian,
Czymmek Karl J.
Publication year - 2019
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2019.01.0010
Subject(s) - surface runoff , index (typography) , nutrient management , water quality , agriculture , environmental science , manure , current (fluid) , phosphorus , agricultural engineering , computer science , engineering , geography , agronomy , ecology , materials science , electrical engineering , archaeology , world wide web , metallurgy , biology
Phosphorus (P) loss from agricultural fields can contribute to water quality degradation. The current New York P index (NY‐PI) scores fields on the basis of P sources and field characteristics that reflect risk of P transport (a source × transport approach). Recently, a transport × best management practice (BMP) approach was proposed, which first scores fields using landscape‐driven transport factors and then offers various BMPs to reduce the score (i.e., risk of P transport). To analyze the score distribution of the current NY‐PI and the incentivizing potential of the proposed structure, a database of 33,327 agricultural fields in New York was assembled in collaboration with nutrient management planners and farmers. Under the current NY‐PI, no additional P could be applied to 2% of the fields, while for 3% the application rates should not exceed annual crop P removal. Flow distance (field to stream) was a major driver for NY‐PI scores. The current NY‐PI relies heavily on soil test P to assess runoff risk, allowing some low‐P fields to receive manure independent of transport risk. A scenario evaluation showed that the proposed NY‐PI limits P application on fields with high transport risk while simultaneously incentivizing adoption of BMPs in such areas. In the absence of farm‐level water quality data, a farm field database can help set P index coefficients and assess implications of a new P index. This study emphasizes the value of involving stakeholders in assessing nutrient management tools, as well as the importance of using an incentive‐driven approach for protecting water resources. Core Ideas Phosphorus indices (PIs) rank farm fields by relative P loss risk. Evaluation and revision of PIs is essential to improve P management over time. Nutrient management planning in New York requires PI evaluation of each field. Management implications of PIs can be analyzed with a database of fields. Scenario analysis with field information can help set PI coefficients.