| Title: | Restructuring the P Index to better address P Management in New York |
| Authors: | Ketterings, Q.M., S. Cela, A.S. Collick, S.J. Crittenden and K.J. Czymmek |
| Year: | 2017 |
| Journal: | Journal of Environmental Quality |
| Volume (Issue): | 46(6) |
| Pages: | 1372-1379 |
| Article ID: | |
| DOI: | 10.2134/jeq2016.05.0185 |
| URL (non-DOI journals): | |
| Model: | Topo-SWAT & SWAT |
| Broad Application Category: | pollutant only |
| Primary Application Category: | BMP and/or cropping system assessment |
| Secondary Application Category: | phosphorus cycling/loss and transport |
| Watershed Description: | Dairy farm with 59 corn fields located in central New York, U.S. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | The New York Phosphorus Index (NY-PI) was introduced in 2001
after the release of the state’s first Concentrated Animal Feeding
Operation (CAFO) Permit that required a nutrient management
plan developed in accordance with NRCS standards. The
stakeholder-based approach to development of the NY-PI,
combined with a requirement for all regulated farms to determine
a NY-PI score for all fields, ensured widespread adoption. While
P management greatly improved over time, the initial NY-PI
overemphasized soil-test P (STP), allowing for P addition if STP
was low, even if the risk of P transport was high. Our goal was
to develop a new PI approach that incentivizes implementation
of best management practices (BMPs) where P-transport risk
is high, building on feedback from certified planners (survey),
analysis of a planner-supplied 33,000+ field database with NYPI
information, and modeling of the impacts of specific BMPs on
P runoff using data from a central NY CAFO farm. We propose a
new NY-PI structure that identifies landscape-driven P-transport
risk if P is surface applied when crops are not actively growing
to reach a raw PI score that is multiplied by credits (factors
£ 1.0) for implementation of BMPs effective in reducing the risk
of P transport. In this “Transport ´ BMP” approach, STP is used
as P application cutoff. This approach could reduce barriers
to regionalization of PIs, as states can identify landscape risk
factors, soil-test cutoffs, and BMPs while maintaining the same
management categories (no manure, P-removal-based rates, or
N-based management). |
| Language: | English |
| Keywords: | |