The Gulf Atlantic Coastal Plain (GACP) Tifton, GA, LTAR site

Authors: Coffin, Alisa

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/13/2018
Publication Date: 2/15/2018
Citation: Coffin, A.W. 2018. The Gulf Atlantic Coastal Plain (GACP) Tifton, GA, LTAR site. Workshop: Emerging Technologies and Methods in Earth Observation for Agricultural Monitoring. Abstract.

Interpretive Summary: Not required.

Technical Abstract: This presentation gives an overview of the Gulf Atlantic Coastal Plain LTAR site. The site is introduced and current and planned research are discussed. The Little River Experimental Watershed (LREW) is a 334 square kilometer watershed, located in the core of the GACP, and situated in the headwaters of the Suwannee River Basin, which flows southward to the Gulf of Mexico. Elevations range from ~50m-130m AMSL in the LREW. Within the LREW, there are a series of nested sub-basins, instrumented with weirs for water flow sampling, designated by letter. Rain gauges also dot the basins, collecting data on precipitation throughout the watershed. The Hawthorn formation underlies the landscape in the GACP and is a structural feature defining its limits. Soils in the region are highly weathered and erodible sandy ultisols. The GACP landscape typically consists of broad valleys of row crops interspersed with riparian forests. Water is impounded and used for irrigation. Major crops in the region are cotton, peanuts and corn, with livestock production consisting of mostly poultry and cattle. Field sizes tend to be small (mean 8.6 ha) and field margins are irregular. The LREW intersects portions of Tift, Worth and Turner counties, where total population in 2012 for all three counties was about 70 thousand people, and incomes tend to be lower than the median income for the US. The GACP is hosted by the USDA-ARS Southeast Watershed Research Laboratory (SEWRL) in Tifton, GA. Within ARS, the SEWRL manages LTAR research through two national programs focused on watershed management and agricultural sustainability. The primary research objective of the GACP with respect to LTAR is to support network research that sustains or enhances agricultural production and environmental quality in agroecosystems characteristic of the GACP region. The GACP science strategies contend with a number of challenges including no permanent access to land for experimental research, relatively small field sizes that introduce confounding factors in earth observation data, low or no replication of experimental designs, technical challenges of spatial scaling and extrapolation, and limited human resources. On the other hand, opportunities available for the GACP include being located in an agricultural landscape with high levels of production and biodiversity, a continuous data record of water flow, water quality and land use, and a long-term partnership with the University of Georgia. Ongoing efforts to tie into earth observation data include ground data collection of biomass, phenology, atmospheric gases, soil moisture, and vegetation indices. These data collection efforts are done with a combination of field data collection and instrumentation using eddy covariance flux towers and umanned aerial vehicles. Field scale research activities in 2018 are planned on four farms, depending on funding status.