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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 ARM Soil Bulk Density Data Set

NAL Geospatial Catalog
    The temporal coverage for this dataset is as follows: Begin datetime: 1995-10-01 00:00:00, End datetime: 2001-03-31 23:59:59. The Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Soil Bulk Density Data Set is one of the various sub-surface data sets developed for the ARM/GCIP (Global Energy and Water Cycle Experiment (GEWEX) Continental-scale International Project) 1996 Near-Surface Observation (NESOB-96) Data Set. This data set contains a summary table of the bulk densities representing the average of the values obtained from the soil water retention samples at each of the ARM SWATS (Soil Water and Temperature System) sites at the SGP site. The soil characterizations were perfomed by Oklahoma State University.

    SGP97 ARM Parameters for Soil Water Retention Models Data Set

    NAL Geospatial Catalog
      The temporal coverage for this dataset is as follows: Begin datetime: 1995-10-01 00:00:00, End datetime: 2001-03-31 23:59:59. The Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Parameters for Soil Water Retention Models Data Set is one of the various sub-surface data sets developed for the ARM/GCIP (Global Energy and Water Cycle Experiment (GEWEX) Continental-scale International Project) 1996 Near-Surface Observation (NESOB-96) Data Set. This data set contains one table for each of the ARM SWATS (Soil Water and Temperature System) sites at the SGP site containing the fitted values of the parameters in the van Genuchten and Brooks-Corey equations for relating soil water pressure to volumetric water content. The soil characterizations were perfomed by Oklahoma State University.

      SGP97 ARM Organic Carbon and Organic Matter Soils Data Set

      NAL Geospatial Catalog
        The temporal coverage for this dataset is as follows: Begin datetime: 1995-10-01 00:00:00, End datetime: 2001-03-31 23:59:59. The Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Organic Carbon and Organic Matter Soils Data Set is one of the various sub-surface data sets developed for the GCIP (Global Energy and Water Cycle Experiment [GEWEX] Continental-scale International Project) Enhanced Observation Period (EOP) Data Set. This data set contains a summary table of the measured organic carbon percentage and the estimated organic matter percentage in the near surface soil at each of the ARM SWATS (Soil Water and Temperature System) sites at the SGP site. The soil characterizations were performed by Oklahoma State University.

        NGPRL Meteorological Towers

        NAL Geospatial Catalog
          This dataset is part of the common observation in the centralized repository for public access, also known as the Common Observatory Repository (CORe), of the USDA ARS Long-Term Agro-ecosystem Research (LTAR) network.

          Nebraska Prairie Study for Agricultural Antibiotic Resistance in Lincoln, Nebraska

            The inherent spatial heterogeneity and complexity of antibiotic resistant bacteria and antibiotic resistance (AR) genes in manureaffected soils makes it difficult to sort out resistance that can be attributed to human antibiotic use from resistance that occurs naturally in the soil. This study characterizes native Nebraska prairie soils that have not been affected by human or food-animal waste products to provide data on background levels of resistance in southeastern Nebraskan soils.