Location: Soil Drainage Research
Project Number: 5080-13210-002-15-A
Project Type: Cooperative Agreement
Start Date: Aug 1, 2017
End Date: Jul 31, 2020
The objectives are to address current research needs by (1) building models for Edge of Field (EOF) monitoring sites, (2) develop subroutines to simulate BMPs and agronomic management strategies, (3) identify gaps in simulation tools and collect novel data to overcome limitations, and ultimately (4) determine optimal practices to simulate sustainable practices in the field in order to minimize nutrient loadings and concentrations at the EOF.
EOF Modeling: Initially, the Agricultural Policy Environmental eXtender (APEX) model will be utilized to simulate the effect of agronomic and best management practices (BMP) on nutrient fate and transport. The PI has previously performed sensitivity analysis and macropore model modifications to improve simulation capabilities of the tool. Data collected from the field and supplemental resources (e.g., SSURGO data) will be used to parameterize the model. Well accepted sensitivity analysis, uncertainty analysis, and model evaluation statistical approaches will be utilized in model development and analysis. Prevailing BMPs and agronomic practices including 4R nutrient stewardship, gypsum additions, drainage water management (among others) will be simulated to assess optimum management strategies for single and stacked BMPs. Sustainability of BMPs under dynamic conditions (both temperature and precipitation) will be assessed. Supplemental Data Collection and Analysis: As is common in numerical modeling, we anticipate high uncertainties due to epistemic error that dampens predictability of dynamics at the EOF and hence we plan to use novel techniques and tracers to identify processes leading to improved prediction and ultimately more precise recommendations for BMPs. A suite of stable isotope tracers of water, phosphate, nitrate and sediments provide insight into fate and transport of contaminants during events, hence we anticipate utilizing these tracers to better quantify pathways and timing of fluxes. Watershed Modeling: Ultimately, the utility of practice implementation at the field scale should be optimized at the environmentally relevant watershed scale. We aim to build collaborations with researchers working with large-scale models (e.g., SWAT) and utilize information derived from APEX to inform such broad-scale modeling efforts.