Concentrated animal feeding operation liquid manure application patterns: Insights from remote sensing
Abstract
The majority of livestock in the United States (US) today is produced in operations where hundreds, or thousands, of animals are concentrated in relatively small areas—those that meet a certain threshold of numbers confined for at least 45 days per year are regulated by the EPA as `concentrated animal feeding operations' (CAFOs) under the Clean Water Act. Many CAFOs store waste in large centralized open air lagoons and then spray the waste as fertilizer onto crops nearby, known as `sprayfields'. Many human and environmental health problems are attributed to CAFOs, yet it is very difficult to understand and mitigate these impacts due to a lack of public data. CAFO locations are not publicly available in most US states, let alone information about manure management and waste application patterns. Our objective was to identify manure applications via irrigation in Duplin County, North Carolina (NC) using a satellite remote sensing classification approach. We expected that irrigation would indicate a manure application during rain-free periods given that most crops in NC are rainfed. We developed a random forest model to identify irrigation on >1,800 distinct sprayfields in Duplin County during the growing season in 2019. The final random forest model incorporated Sentinel-1 radar VV polarization, elevation, slope, and crop type, and relied on field measurements of soil moisture (20 cm depth) collected across a statewide flux tower network for model training (30% of pixels withheld for validation). The model successfully distinguished saturated and unsaturated corn, soy, and other crops with >91% accuracy. Future work can build on these methods to classify manure applications during different seasons, and help to quantify manure application frequencies, thereby helping to estimate watershed nutrient loads from CAFOs. This work can highlight the spatial impact of CAFOs, aid in identification of CAFOs, and support strategies to mitigate the impacts from these facilities.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMH158...05S
- Keywords:
-
- 1804 Catchment;
- HYDROLOGY;
- 1829 Groundwater hydrology;
- HYDROLOGY;
- 1830 Groundwater/surface water interaction;
- HYDROLOGY;
- 1871 Surface water quality;
- HYDROLOGY