Phosphorus (P) budgets can be useful tools for understanding nutrient cycling and quantifying the effectiveness of nutrient management planning and policies; however, uncertainties in agricultural nutrient budgets are not often quantitatively assessed. The objective of this study was to evaluate uncertainty in P fluxes (fertilizer/manure application, atmospheric deposition, irrigation, crop removal, surface runoff, and leachate) and the propagation of these uncertainties to annual P budgets. Data from 56 cropping systems in the P-FLUX database, which spans diverse rotations and landscapes across the United States and Canada, were evaluated. Results showed that across cropping systems, average annual P budget was 22.4 kg P ha−1 (range = −32.7 to 340.6 kg P ha−1), with an average uncertainty of 13.1 kg P ha−1 (range = 1.0–87.1 kg P ha−1). Fertilizer/manure application and crop removal were the largest P fluxes across cropping systems and, as a result, accounted for the largest fraction of uncertainty in annual budgets (61% and 37%, respectively). Remaining fluxes individually accounted for <2% of the budget uncertainty. Uncertainties were large enough that determining whether P was increasing, decreasing, or not changing was inconclusive in 39% of the budgets evaluated. Findings indicate that more careful and/or direct measurements of inputs, outputs, and stocks are needed. Recommendations for minimizing uncertainty in P budgets based on the results of the study were developed. Quantifying, communicating, and constraining uncertainty in budgets among production systems and multiple geographies is critical for engaging stakeholders, developing local and national strategies for P reduction, and informing policy.
|Number of pages||13|
|Journal||Journal of Environmental Quality|
|State||Published - Jul 1 2023|
Bibliographical noteFunding Information:
The authors would like to thank the technicians and support staff across contributing sites for their efforts in collecting, analyzing, and compiling the data used in the study. This research was a contribution from the Long‐Term Agroecosystem Research (LTAR) network. LTAR is supported by the United States Department of Agriculture.
The authors would like to thank the technicians and support staff across contributing sites for their efforts in collecting, analyzing, and compiling the data used in the study. This research was a contribution from the Long-Term Agroecosystem Research (LTAR) network. LTAR is supported by the United States Department of Agriculture.
Published 2023. This article is a U.S. Government work and is in the public domain in the USA.
ASJC Scopus subject areas
- Environmental Engineering
- Water Science and Technology
- Waste Management and Disposal
- Management, Monitoring, Policy and Law