Nutrient management planners' feedback on New York and Pennsylvania phosphorus indices

Abstract

State phosphorus indices (PIs) are being evaluated across the United States due to variability in phosphorus (P) management recommendations and questions about the lack of water quality improvement in some watersheds. Nutrient management planners in New York (NY) and Pennsylvania (PA) were surveyed via two separate "but related" questionnaires to document perspectives on the current NY-PI and PA-PI and to obtain recommendations for improvements. Many planners were content with the current versions of the PIs but felt improvements could be made to more strongly discourage application of manure under conditions of high P loss potential and better promote certain best management practices. The NY planners felt that the NY-PI should discourage manure application during winter and to fields near streams, and should more strongly promote manure incorporation or injection, establishment of cover crops, ground coverage with crop residues, and implementation of setbacks and vegetated buffers. Similarly, the PA planners felt that the PA-PI should more strongly discourage manure application to fields with insufficient ground cover, near subsurface drainage and surface inlets, and during winter. In addition, the PA planners said the PA-PI should more strongly encourage soil conservation practices such as no-till, use of cover crops, and vegetated buffers. Results of the survey suggest common experiences and viewpoints among planners in NY and PA, resulting in a valuable on-theground assessment of the PIs as a nutrient management planning tool in both states, and the potential for development of a single, physiographic region PI.

Restructuring the P Index to Better Address P Management in New York

“…The feedback from the planners indicated a high ranking for relevance of all transport P factors in the initial NY‐PI. They did, however, suggest that a new NY‐PI could more strongly discourage manure application during winter and to fields near streams and could more strongly promote manure incorporation or injection, establishment of cover crops, maintenance of ground cover with crop residues, and implementation of setbacks within production fields and vegetated buffers outside of fields (Cela et al, 2016). This feedback was consistent with findings that the NY‐PI allows for relatively high manure application rates when STP is low, even if the risk of transport of the manure to streams is high.…”

“…Building on the importance of a stakeholder‐driven process already employed with the development of the initial NY‐PI, a second survey was developed to specifically request feedback on the NY‐PI, while a very similar survey was conducted in Pennsylvania with focus on the Pennsylvania PI (Weld et al, 2007) to enable comparisons across state boundaries. These surveys, conducted in 2014 to 2015, showed that the current versions of each PI were well accepted in their respective states, documented the type of management practices that planners experienced as high risk, and identified overreliance on STP as an issue in high‐risk scenarios (Cela et al, 2016). Lessons learned from the survey were used to guide development of a new NY‐PI approach and to identify transport factors and BMPs to be included in the new NY‐PI.…”

“…Feedback from New York planners (Cela et al, 2016) resulted in identification of a series of management practices that planners felt were important to incentivize in a revised NY‐PI in future years. This included incorporation or injection of manure, while discouraging surface application without mixing with soil, and establishment of cover crops.…”

“…Furthermore, New York certified nutrient management planners with clients in neighboring states had voiced a desire for more unification in PI assessment across state lines, similar to feedback in other states with land area within the CBW. Thus, the states with agricultural land within the CBW started to evaluate the feasibility of PI assessments and recommendations within physiographic regions (Kleinman et al, 2012), an improvement that would be welcomed by certified planners with clients in multiple states, as documented for New York and Pennsylvania in Cela et al (2016).…”

Phosphorus and the Chesapeake Bay: Lingering Issues and Emerging Concerns for Agriculture

“…The emergence of dissolved P in watersheds such as the Conestoga (Fig 1; Table 1) reflects an array of recalcitrant sources of P, exacerbated by increased infrastructure needs of small livestock operations (Kleinman et al, 2012). Although conservation tillage is widespread in the region (roughly two‐thirds of the Bay watershed's farm soils are in no‐till or some type of perennial forage), adoption of cover crops in Pennsylvania is not as extensive as in Maryland, where it has been heavily subsidized (13 vs. 29% of cropland area in Pennsylvania and Maryland, respectively, in 2017), and soil erosion remains a dominant concern of nutrient management specialists and resource conservation programs (Cela et al, 2016; Bryant, 2019). Even so, the emergence of dissolved P as a concern may also reflect the success of soil conservation programs, which struggle to deal with the persistent issue of vertical soil P stratification (Baker et al, 2017).…”