Delineating Conservation Practices in a Nutrient Impaired Watershed: High Rock Lake Watershed, NC.

North Carolina consists of 17 riverbasins, two (Neuse and Tar-Pamlico) of which are impaired for nutrients and are on the USEPA 303(d) list. Specific nutrient reductions (nitrogen and phosphorus) are required to meet imposed TMDLs.  A large portion (Highrock Lake watershed) of another river basin (Yadkin-PeeDee) is currently under rulemaking and agriculture is considered to be a significant source of the nutrients as 30% of land use is pasture/hay and there is some cropland.  To better delineate agricultural practices in the High Rock watershed, an on-the-ground agricultural survey was conducted of over 1000 farmers to assess cropping systems, nutrient application rates, soil testing frequency, nutrient behavior, animal numbers and stocking rates, and the use of conservation practices such as riparian buffers, conservation tillage, and other practices.  Sample selection was randomized and fields selected for sampling were determined using an area frame sample such that area segments covering the entire basin had roughly the same number of fields and all had clearly marked boundaries.  Data suggest that there are many landowners tending small fields (<10 acres).  Conservation tillage is used on almost all cropped acres and fields of hay and pasture are generally underfertilized. Although some of the streams and ditches are buffered there is opportunity for greater conservation relative to filter strips and/or riparian buffer installation. These on-the-ground surveys provide significantly more data than USDA Agricultural Survey or Census data and are invaluable for modeling work that is conducted in these impaired watersheds and river basins.