Impacts of Changing Weather Patterns and Land Management Decisions on Nutrient Fluxes
Abstract
Freshwater resources are increasingly impacted by excessive chemical inputs from diffuse- and point-sources of pollution. Processes and decisions related to land and water management, including food production - fertilizer applications, livestock operations and manure management, discharges from sewage and wastewater treatment, are major factors that contribute to excessive pollution and water quality impairment. In many intensively managed agricultural landscapes, changing weather patterns, particularly precipitation which is one of the key drivers of the water cycle, affect budgets of key nutrients such as nitrogen (N) and phosphorus (P). While overall application rates have declined, and plant uptake efficiencies have improved over the past decades, increasing intensity of severe weather creates biogeochemical "hot moments" where large quantities of N and P are released into receiving waters within a short period of time. Here, with the use of high-dimensional geospatial data and biophysical models, we attempt to elucidate how these hot moments combined with land management decisions alter overall N and P budgets. The biophysical model incorporates daily weather forcings, biophysical properties of landscapes and human decisions such as cropping systems, and N and P inputs in several Midwestern United States watersheds. Our preliminary results indicate that timing, application rates and type of N and P combined with severe weather greatly influence the inter-annual variations in nutrient budgets. Shorter duration and intense precipitation events early in the growing season create hot moments where disproportionately high amounts of N and P are lost from managed landscapes. Our findings would provide valuable insights toward developing sustainable nutrient management strategies in managed landscapes.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMGC12C..04A