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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

    602 datasets

    SGP97 Surface: NOAA/ATDD Little Washita, Oklahoma Long Term Flux Site

    NAL Geospatial Catalog
      The temporal coverage for this dataset is as follows: Begin datetime: 1997-05-31 00:00:00, End datetime: 1997-08-09 23:59:59. NOAA/ATDD (Tilden Meyers) started operation of a long term flux monitoring site near the Little Washita watershed in Oklahoma in 1996. Half-hourly observations of wind speed and direction, air temperature, relative humidity, pressure, incoming global radiation, incoming and outgoing visible radiation, net radiation, ground heat flux, precipitation, wetness, skin temperature, soil temperature (at 2, 4, 8, 16, 32 and 64 cm), average wind vector speed, kinematic shear stress, streamwise velocity variance, crosswind velocity variance, vertical velocity variance, sensible heat flux, latent energy flux, CO2 flux and soil moisture at 20 cm (started 5 June 1997).

      Data from: Plant Tissue Characteristics of Miscanthus x giganteus

        As part of a study identifying relationships between environmental variables and insect distributions within a bioenergy crop, giant miscanthus (Miscanthus x giganteus) samples were collected in October 2016 at 33 locations within a field in southeast Georgia, USA. This dataset describes the chemical composition of giant miscanthus leaves and stems including the total carbon (TC) and nitrogen (TN) content, total macro- and micronutrients.

        Sample of Mandan, North Dakota Aerial Image Dataset

          Originally produced by the Farm Security Administration, these are georeferenced aerial images from Morton County, North Dakota. Historic print images housed at the Mandan, North Dakota ARS Long-Term Agricultural Research facility were digitized, georeferenced, and processed for use in both professional and consumer level GIS applications, or in photo-editing applications. The original images were produced by the Farm Security Administration to monitor government compliance for farm land agreements. Current applications include assessing land use change over time with regard to erosion, land cover, and natural and man-made structures. Not for use in high precision applications.

          Manure Cycling Interview Data

          Jornada Experimental Range LTAR
            Exploring the potential for nutrient circularity in the beef production system requires an understanding of current practices. Manure nutrients produced in feedlots are an ample source of fertilizer for phosphorus deficient crop and hay lands.

            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.