Location: Southeast Watershed Research
2022 Annual Report
Accomplishments
1. Validation of Remotely Sensed Soil-Water. Estimates of soil moisture across the globe are critical for prediction of climate, water balance, and crop production. Soil moisture is fundamental to agricultural management and provides critical information on hydrologic and climatic processes. The Little River Experimental Watershed (LREW) managed by ARS researchers in Tifton, Georgia, is part of a nation-wide network of core validation sites collecting continuous in-situ soil-water across large spatial areas. This network has played a crucial role in the calibration and validation of satellite based remotely sensed soil-water. In-situ data collected from this network has helped to improve the accuracy of remotely sensed soil-moisture by 40% from 2002 to 2020. The credibility of the remotely sensed data has been greatly enhanced by the testing provided by this nationwide in-situ network. The LREW provides a unique data set for the diverse Coastal Plain landscape. Soil moisture satellite products are being used to improve drought analysis. Soil moisture products from SMOS and SMAP have been used to improved flood forecasting as well. Soil moisture products are being incorporated operationally to improved continental National Weather Service Noah Models. The LREW is currently one of eight ARS watersheds conducting satellite scale soil moisture calibration and validation activities at increasingly finer scales, bringing soil moisture monitoring closer to scales relevant to field-level management.
2. Importance of Long-term data in understanding soil moisture. Soil moisture is fundamental to agricultural management and provides critical information on hydrologic and climatic processes. The validation of national and global soil moisture utilizing data collected from satellites and simulated by numerical models uses ground-based measurements for verification purposes. The ground-based measurements are often assumed stable over time, but there has been little research demonstrating the consistency of a data and their variability over time. A nationwide study including ARS researchers in Tifton, Georgia, and from several other ARS watershed locations, found that ground-based measurements were able to adequately capture a full range of soil moisture conditions within one calendar year. The incorporation of long-term soil moisture data is helping to improve national and global models of soil moisture dynamics, including drought impacts, and is encouraging for network scaling activities and validation campaigns.
Review Publications
Anderson, W.F., Knoll, J.E., Olson, D.M., Scully, B.T., Strickland, T.C., Webster, T.M. 2022. Winter legume cover effects on yields of biomass-sorghum and cotton in Georgia. Agronomy Journal. 114(2):1298-1310. https://doi.org/10.1002/agj2.21018.
Liu, P., Bindlish, R., O'Neil, P., Fang, B., Lakshmi, V., Yang, Z., Cosh, M.H., Bongiovanni, T., Holifield Collins, C.D., Starks, P.J., Prueger, J.H., Bosch, D.D., Seyfried, M.S., Williams, M.R. 2022. Thermal hydraulic disaggregation of SMAP soil moisture over continental United States. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 15:4072-4093. https://doi.org/10.1109/JSTARS.2022.3165644.
Pisani, O., Liebert, D.P., Strickland, T.C., Coffin, A.W. 2022. Plant tissue characteristics of Miscanthus x giganteus. Scientific Data. 9:308. https://doi.org/10.1038/s41597-022-01424-0.
Williams, M.R., Welikhe, P., Bos, J.H., King, K.W., Akland, M., Augustine, D.J., Baffaut, C., Beck, G., Bierer, A.M., Bosch, D.D., Boughton, E., Brandani, C., Brooks, E., Buda, A.R., Cavigelli, M.A., Faulkner, J., Feyereisen, G.W., Fortuna, A., Gamble, J.D., Hanrahan, B.R., Hussain, M., Kohmann, M., Kovar, J.L., Lee, B., Leytem, A.B., Liebig, M.A., Line, D., Macrae, M., Moorman, T.B., Moriasi, D.N., Nelson, N., Ortega-Pieck, A., Osmond, D., Pisani, O., Ragosta, J., Reba, M.L., Saha, A., Sanchez, J., Silveira, M., Smith, D.R., Spiegal, S.A., Swain, H., Unrine, J., Webb, P., White, K.E., Wilson, H., Witthaus, L.M. 2022. P-FLUX: A phosphorus budget dataset spanning diverse agricultural production systems in the United States and Canada. Journal of Environmental Quality. 51:451–461. https://doi.org/10.1002/jeq2.20351.
