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Long Term Agroecosystem Research Overview

In pursuit of sustainable U.S. agriculture, the U.S. Department of Agriculture (USDA) launched the Long-Term Agroecosystem (LTAR) network. The LTAR network is composed of 18 locations distributed across the contiguous United States working together to address national and local agricultural priorities and advance the sustainable intensification of U.S. agriculture.

The LTAR network represents a range of major U.S. agroecosystems, including annual row cropping systems, grazinglands, and integrated systems representative of roughly 49 percent of cereal production, 30 percent of forage production, and 32 percent of livestock production in the United States. Furthermore, the LTAR sites span geographic and climatic gradients representing a variety of challenges and opportunities to U.S. agriculture.

The LTAR network uses experimentation and coordinated observations to develop a national roadmap for the sustainable intensification of agricultural production. While the LTAR network is a new network, experimentation and measurements began at some LTAR sites more than 100 years ago, while other locations started their research as recently as 19 years ago.

A primary goal of LTAR is to develop and to share science-based findings with producers and stakeholders. Tools, technologies, and management practices resulting from LTAR network science will be applied to the sustainable intensification of U.S. agriculture. Technical innovations, including new production techniques, genetics, and sensor infrastructure applied at the farm/ranch level can increase the capacity for adaptive management, reduce time and operational costs, and increase profits and the quality of life for producers.

For full list of LTAR sites, view the sites matrix at https://ltar.ars.usda.gov/sites/.

For more information about the LTAR network visit: https://ltar.ars.usda.gov

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Datasets

596 datasets

SGP97 GCIP/NESOB-97 Surface: 15-Minute Precipitation Composite

NAL Geospatial Catalog
    This precipitation composite was formed from two data sources (National Climatic Data Center (NCDC) Fifteen Minute Precipitation data (TD 3260), and fifteen minute precipitation extracted from the Department Of Energy (DOE) Atmospheric Radiation Measurement Surface (ARMSFC) five minute surface data).

    SGP97 GCIP/NESOB-97 Sub-Surface: National Climatic Data Center (NCDC) Daily Soil Temperature Dataset

    NAL Geospatial Catalog
      This dataset was formed by extracting soil temperature data from the GCIP/Enhanced Seasonal Observing Period 1997 (GCIP/ESOP-97) NCDC Summary of the Day Co-operative Dataset (TD-3200) for the NESOB 1997 area and time of interest. This NCDC Soil Temperature Dataset contains data from approximately 12 stations reporting soil temperature data for the NESOB 1997 time period (01 April 1997 through 31 March 1998) and in a domain slightly beyond that of NESOB 1997 (approximately 94.5W to 102W longitude and 34N to 39.5N latitude).

      SGP97 GCIP/NESOB Surface: Skin Temperature Composite

        This Skin Temperature composite was formed from three data sources: the 10m and 25m ARM/Clouds and Radiation Testbed (CART) Multi-Filter Radiometer (MFR) 20 second data, and 30 minute data from the GCIP National Oceanic and Atmospheric Administration (NOAA)/Atmospheric Turbulence and Diffusion Division (ATDD) Little Washita, Oklahoma long term flux monitoring site. This composite was developed by the merging of the 30-minute averaged values of skin temperature as provided by NOAA/ATDD for its Little Washita station and the 30-minute averaged values of skin temperature as derived by University Corporation for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS) from the 20-second values provided by ARM for its 10m and 25m MFR stations. UCAR/JOSS computed standard deviations for the ARM 10m and 25m MFR data when at least 15 observations were available within the 30-minute averaging interval.

        SGP97 GCIP/NESOB Surface: Shortwave and Longwave Radiation Composite

          This composite was developed by the merging of the 30-minute averaged values of Irradiance as derived by University Corporation for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS) from the 20-second values provided by ARM for its 25m MFR station and its SIROS and SIRS stations; the 30-minute averaged values of Irradiance as derived by UCAR/JOSS from the 1-minute values provided by ARM for its BSRN station; and the hourly values provided by HPCN. UCAR/JOSS computed standard deviations for the averaged irradiance data when at least 15 observations were available within the 30-minute averaging interval.

          SGP97 GCIP/NESOB Surface: Sensible, Latent and Ground Heat Flux Composite

            This Sensible, Latent and Ground Heat Flux composite was formed from three data sources: the ARM Southern Great Plains (SGP) Clouds and Radiation Testbed (CART) Energy Balance/Bowen Ratio (EBBR) sites, the National Oceanic and Atmospheric Administration (NOAA)/Atmospheric Turbulence and Diffusion Division (ATDD) Little Washita Watershed site, and the ARM SGP Eddy Correlation (ECOR) sites. Data from 14 ARM/EBBR stations, 1 NOAA/ATDD station, and 8 ARM/ECOR stations were merged to form this composite.

            SGP97 GCIP/NESOB Surface: Net Radiation and PAR Composite

              This composite was developed by the merging of the computed 30-minute averaged values of Net Radiation as derived by University Corporation for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS) from the 20-second values provided by ARM for its SIROS and SIRS stations, and the 30-minute averaged values of Incoming/Outgoing PAR and Net Radiation as provided by NOAA/ATDD for its Little Washita station. UCAR/JOSS computed standard deviations for the averaged data when at least 15 observations were available within the 30-minute averaging interval.