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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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LTAR Research Sites

Data from the following LTAR sites are presented. They are related to topics such as agricultural sustainability, climate change, ecosystem services, and natural resource conservation at the watershed or landscape scale.

  • Archbold Biological Station (ABS), Venus, FL
  • Cook Agronomy Farm (CAF), Pullman, WA
  • Central Mississippi River Basin (CMRB), Columbia, MO
  • Central Plains Experimental Range (CPER), Cheyenne, WY; Fort Collins, CO; Nunn, CO
  • Eastern Corn Belt (ECB), Columbus, OH; West Lafayette, IN
  • Gulf Atlantic Coastal Range (GACP), Tifton, GA
  • Great Basin (GB), Boise, ID; Burns, OR
  • Jornada Experimental Range (JER), Las Cruces, NM
  • Kellogg Biological Station (KBS), southwestern MI
  • Lower Mississippi River Basin (LMRB), Oxford, MS; AR; LA; MO
  • Northern Plains (NP), Mandan, ND
  • Platte River-High Plains Aquifer (PRHP), Lincoln, NE
  • Southern Plains (SP), El Reno, OK
  • Texas Gulf (TG), Riesel, TX
  • Upper Chesapeake Bay (UCB), University Park, PA
  • Upper Mississippi River Basin (UMRB), Ames, IA; MN; WI
  • Walnut Gulch Experimental Watershed (WGEW), Tucson, AZ; Tombstone, AZ
  • Lower Chesapeake Bay (LCB), Beltsville, MD

    • Datasets

    619 datasets

    TPAC Study for Greenhouse gas Reduction through Agricultural Carbon Enhancement network in West Lafayette, Indiana

      This research project was conducted to assess the influence of cropping system management on non-carbon dioxide (non-CO2) GHG emissions from an eastern cornbelt alfisol. Corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) rotation plots were established, as were plots in continuous management of native grasses or Sorghum/Sudan grass. GHG fluxes were monitored throughout each growing season from 2004 through 2007.

      Data from: Interseeded cover crop mixtures influence soil water storage during the corn phase of corn-soybean-wheat no-till cropping systems

        This study was initiated to evaluate, during the following corn (*Zea mays* L.) phase, the effects of interseeded cover crops on soil temperature, soil water balances, evapotranspiration, infiltration, and yield and water use efficiency of corn. The study was conducted at the USDA Beltsville Agricultural Research Center, Beltsville, MD from 2017 through 2020. The cropping systems under study were primarily sequences of corn-soybean (*Glycine max* L.)-wheat (*Triticum aestivum* L.)-double crop soybean all planted with no-tillage management.

        Eddy Covariance Data from Office of Naval Research Biofuel project on Maui

          These data come from three eddy covariance (EC) towers that were installed as part of a project to assess the productivity of sugarcane agricultural systems for biofuel production. These towers were operated from 2011-2013 in Maui, USA. Major observational parameters include net carbon exchange, evapotranspiration, and energy fluxes.

          Reynolds Creek Experimental Watershed, Idaho (Lysimeter)

            Lysimeters are instruments that measure water and/or solute movement in soils. The primary purpose for these lysimeters was to measure evapotranspiration (ET); these data describe changes in soil water during the snow-free season. In addition to measuring changes in total soil water, soil water content profiles and soil temperature profiles were measured within or adjacent to the lysimeters and are reported. Two pairs of soil lysimeters were installed in the RCEW in 1967, one pair at the Lower Sheep Creek climate station (designated the east and west lysimeters), separated, center to center, by 3.6 m, and the other pair at the Reynolds Mountain climate station (designated north and south), separated by 4.7 m. These lysimeters were hydraulic weighing lysimeters in which an inner cylindrical tank containing soil is set within a slightly larger outer cylinder.