ACHIEVING LONG-TERM PROTECTION OF WATER QUALITY OF GRAND LAKE ST. MARYS THROUGH THE CONTROL OF PHOSPHOROUS INPUT FROM AGRICULTURAL PRACTICES
Soil Drainage Research
2012 Annual Report
1a.Objectives (from AD-416):
Evaluate sources of phosphorus within the Grand Lake St. Marys watershed and provide support for conservation management plan development through watershed monitoring and modeling. The USDA Annualized Agricultural Non-Point Source (AnnAGNPS) pollution model will be used and monitoring information will be used for model calibration and validation. Effective conservation and drainage control practices will be identified that improves the water quality within the GLSM.
1b.Approach (from AD-416):
Install equipment to measure hydrology and collect water samples from paired field sites with and without applied conservation practice (cover crop initially). Analyze water samples for N, P, and sediment. Collect farming input data and yields data. Calibrate and validate AnnAGNPS for GLSM watershed, and evaluate multiple scenarios to optimize the impact of conservation practice placement within the watershed especially related to control of phosphorus discharge to streams and ultimately to Grand Lake St. Marys.
To date, we have identified with the assistance of Ohio State University Extension one land owner in the Beaver Creek subwatershed of the Grand Lake St Mary watershed willing to let us install edge-of-field data sampling equipment. A pair of both surface and subsurface data collection equipment was installed in early 2012 to collect hydrology and water quality data. Soil samples were taken in early March from each field in the pair. Progress continues to be made on populating the Annual Agricultural Non-Point Source Pollution Model (AnnAGNPS) for best management practice scenario analyses. A project partnership meeting was held in the watershed and information was shared with stakeholders.
The work and progress associated with this project support objective 1 of the parent project, specifically sub-objective 1a: Quantify the influence of conservation practices on surface discharge and water chemistry in the agricultural landscape and sub-objective 1b: Conduct field and watershed-scale studies of hydrology, nutrient, and agrichemical contributions originating from subsurface drainage.