The
Long-Term Agroecosystem Research Network

About

The Long-Term Agroecosystem Research (LTAR) Network is designed to address national issues related to agricultural production, sustainability, off-site effects, and socioeconomic impacts on rural communities as affected by climate. More on the LTAR science plan can be found in our Shared Research Strategy.

What Is LTAR?

The Long-Term Agroecosystem Research (LTAR) Network is a partnership among 18 premier long-term research sites across the United States.

LTAR was established to build the knowledge required for sustainable intensification of agriculture, increasing yields from the current agricultural land base while minimizing or reversing agriculture’s adverse environmental impacts.

Network research is organized around topics of sustainability of regional or national consequence, relying upon long-term databases, cross-site experiments, and computational modeling to tie experimental and monitoring conclusions from diverse locations to a broader vision of agriculture for the United States.

Why Is It Important?

Currently, most agricultural science in the United States focuses on improving productivity and efficiency. In contrast, the LTAR network has a multifaceted focus on satisfying increasing demand for agricultural commodities, protectingthe quality of the environment, and enhancing the quality of life in rural areas and the Nation as a whole.

What Is Expected?

The network is uniquely positioned to ensure sustained crop and livestock production and ecosystem services from the regional agroecosystems of the United States, and to leverage those local findings to support a national-scale transition to sustainable intensification.

Current Impacts

LTAR will provide information to producers, and policymakers at the local, State, and national levels regarding how innovation, incentives, and regulations may impact economic opportunity and the health of agricultural communities and landscapes.

Research Prioritization

LTAR network research will be prioritized around the following questions related to sustainable intensification.

  1. What factors drive agricultural productivity and its environmental impacts?
  2. What are the tradeoffs between productivity, quality, societal preferences, and ecosystem services?
  3. What are the barriers to sustainable intensification?
  4. How do we better target our use of resources?
  5. What technologies and management strategies are needed for agriculture to be resilient to extreme events (e.g., weather, disease outbreaks, pest infestations)?
  6. What scientific synthesis products are needed for decision making?

These concepts are incorporated in the following organizational chart:

LTAR Working Groups

The list of LTAR Working Groups

Common Experiment

Cropland Working Group

The LTAR Common Experiment Cropland Working Group

Rangeland Working Group

The LTAR Common Experiment Rangeland Working Group

Observatory

Biological

The LTAR Biological Working Group

Data Management

The LTAR Data Management Working Group

Eddy Flux CO2

The LTAR Eddy Flux CO2 Working Group

Hydrology

The Hydrology Working Group

Meteorology

The LTAR Meteorology Working Group

Non CO2 Gases

The Non CO2 Gases Working Group

Remote Sensing/GIS

The Remote Sensing/GIS Working Group

Soils

The Soils Working Group

Wind Erosion

The Wind Erosion Working Group

Network Status

This matrix shows the status of the LTAR Network

  Common Experiment - Rangeland
  Business as Usual System (BAU)
Field-Scale Treatment
Aspirational System (ASP)
Field-Scale Treatment
Archbold Biological Station
Central Mississippi River Basin NA NA
Central Plains Experimental Range
Eastern Corn Belt NA NA
Great Basin
Gulf Atlantic Coastal Plain NA NA
Jornada Experimental Range
Kellogg Biological Station NA NA
Lower Chesapeake Bay NA NA
Lower Mississippi River Basin NA NA
Northern Plains NA NA
Platte River/High Plains Aquifer NA NA
R.J. Cook Agronomy Farm
Southern Plains NA NA
Texas Gulf NA NA
Upper Chesapeake Bay NA NA
Upper Mississippi River Basin NA NA
Walnut Gulch Experimental Watershed Mesquite Treatment
  Common Experiment - Cropland
  Business as Usual System (BAU)
Field-Scale Treatment
Aspirational System (ASP)
Field-Scale Treatment
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range NA NA
Eastern Corn Belt
Great Basin NA NA
Gulf Atlantic Coastal Plain
Jornada Experimental Range NA NA
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed NA NA
  Biological
  ANPP Food Production Phenology Plant tissue chemistry Soil microbial abundance/diversity Decomposition Weed indicators Biodiversity indicators Remote sensing and LULC
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  Eddy Flux CO2
  Dataset 1 Dataset 2 Dataset 3 Dataset 4 Dataset 5
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  Hydrology
  Discharge Surface Runoff Subsurface Flow Soil Moisture Groundwater Level Irrigation Inputs Forms of N and P Suspended Sediment Selected Herbicides Conductivity Total Dissolved Solids Chloride ET
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  Meteorology Phase I Meteorology Phase II
  Air temperature/ relative humidity Wind speed and direction Precipitation Phenology camera Barometric pressure Short and long-wave radiation (PAR) incoming
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  Non-CO2 Gases
  N2O CH4 NH3 NO2 N2 VOC
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  Soils
  Soil Morphology Texture Bulk Density pH EC Exchangable Cations and CEC Total C and N Total and Water Extractable P
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  Wind Erosion
  Dataset 1 Dataset 2 Dataset 3 Dataset 4 Dataset 5
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  Remote Sensing
  Multi-Spectral Imagery Aerial Photography Precipitation Dataset 4 Dataset 5
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  Data Management
  Raw Data Meta Data QA/QC Data Phenocam Data
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed
  GIS Datasets
  Watershed Boundaries Elevation Soils Hydrology Land Cover Geology Socio-Economic
Archbold Biological Station
Central Mississippi River Basin
Central Plains Experimental Range
Eastern Corn Belt
Great Basin
Gulf Atlantic Coastal Plain
Jornada Experimental Range
Kellogg Biological Station
Lower Chesapeake Bay
Lower Mississippi River Basin
Northern Plains
Platte River/High Plains Aquifer
R.J. Cook Agronomy Farm
Southern Plains
Texas Gulf
Upper Chesapeake Bay
Upper Mississippi River Basin
Walnut Gulch Experimental Watershed

Timeline

This is the LTAR project timeline (so far).

  • 2008

    Robertson et al. paper describing need for an LTAR

  • 2011

    Walbridge and Shafer paper describing start of LTAR

  • 2011

    1st RFI (Request for Information)

    RFI resulting in the initial selection of Central Plains Experimental Station, Goodwater Creek Experimental Watershed, Jornada Experimental Range, Little River Experimental Watershed, Little Washita River/Fort Cobb Reservoir Experimental Watersheds, Northern Great Plains Research Laboratory, R.J. Cook Agronomy Farm, Upper Chesapeake Bay Experimental Watersheds, Upper Mississippi River Basin Experimental Watersheds, Walnut Gulch Experimental Watershed as LTAR sites.

  • 2012

    2nd RFI (Request for Information)

    2nd RFI resulting in the selection of Archbold-University of Florida, Eastern Corn Belt, Great Basin, Michigan State University WK Kellogg Biological Station, Lower Chesapeake Bay, Lower Mississippi River Basin, Platte River-High Plains Aquifer, Texas Gulf Research Partnership.

  • 2012

    LTER Annual Conference in Estes Park, CO

  • 2014

    LTAR Annual Conference at the Central Plains Experiment Station

  • 2015

    LTAR Annual Conference at the Lower Chesapeake Bay

  • 2016

    LTAR Annual Conference at the Archbold Biological Station

  • 2017

    LTAR Annual Conference at Southern Plains

LTAR Publications

A list of publications related to the LTAR Network

Published


2008

G. Philip Robertson, Vivien G. Allen, George Boody, Emery R. Boose, Nancy G. Creamer, Laurie E. Drinkwater, James R. Gosz, Lori Lynch, John L. Havlin, Louise E. Jackson, Steward T. A. Pickett, Louis Pitelka, Alan Randall, A. Scott Reed, Timothy R. Seastedt, Robert B. Waide, And Diana H. Wall. 2008. Long-term Agricultural Research: A Research, Education, and Extension Imperative BioScience, Vol. 58 No. 7.
http://bioscience.oxfordjournals.org/content/58/7/640.full


2011

Mark R. Walbridge and Steven R. Shafer. 2011. A Long-Term Agro-Ecosystem Research (LTAR) Network for Agriculture, The Fourth Interagency Conference on Research in the Watersheds, 26–30 September 2011, Fairbanks, AK.
https://www.ars.usda.gov/ARSUserFiles/np211/LTAR%20Walbridge%20and%20Shafer%202011%20Paper.pdf


2015

Jean L. Steiner, Timothy Strickland, Peter J.A. Kleinman, Kris Havstad, Thomas B. Moorman, M. Susan Moran, Phil Heilman, Ray B. Bryant, David Huggins, and Greg McCarty. 2016. The Long Term Agroecosystem Research Network – Shared Research Strategy. p. 42-51. Proceedings of the Fifth Interagency Conference on Research in the Watersheds in Stringer, Christina E.; Krauss, Ken W.; Latimer, James S., eds. 2016. Headwaters to estuaries: advances in watershed science and management—Proceedings of the Fifth Interagency Conference on Research in the Watersheds. March 2-5, 2015, North Charleston, S outh Carolina. e-Gen. Tech. Rep. SRS-211. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 302 p.
http://www.srs.fs.usda.gov/pubs/gtr/gtr_srs211/gtr_srs211_014.pdf


Sadler, E. J., K. A. Sudduth, S. T. Drummond, E. D. Vories, and P. E. Guinan. 2015. Long-Term Agroecosystem Research in the Central Mississippi River Basin: Goodwater Creek Experimental Watershed Weather Data. J. Environ. Qual. 44:13-17. doi:10.2134/jeq2013.12.0515
https://dl.sciencesocieties.org/publications/jeq/pdfs/44/1/13


2016

Nicholas P. Webb , Jeffrey E. Herrick, Justin W. Van Zee, Ericha M. Courtright, Christopher H. Hugenholtz, Ted M. Zobeck, Gregory S. Okin, Thomas E. Barchyn, Benjamin J. Billings, Robert Boyd, Scott D. Clingan, Brad F. Cooper, Michael C. Duniway, Justin D. Derner, Fred A. Fox, Kris M. Havstad a , Philip Heilman, Valerie LaPlante, Noel A. Ludwig, Loretta J. Metz, Mark A. Nearing, M. Lee Norfleet, Frederick B. Pierson, Matt A. Sanderson, Brenton S. Sharratt, Jean L. Steiner, John Tatarko, Negussie H. Tedela, David Toledo, Robert S. Unnasch, R. Scott Van Pelt, Larry Wagner. 2016. The National Wind Erosion Research Network: Building a standardized long-term data resource for aeolian research, modeling and land management. Aeolian Research 22 (2016) 23–36.
http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcseprd1101806.pdf

Publications Under Development

  • LTAR and the Sustainability of US Agriculture
  • N2O
  • Budgets (H2O, C, N, P)
  • Biodiversity
  • Precipitation Intensification (All sites at Daily, sub-set of sites at sub-daily)
  • All sites SPEI (Standardized Precip Evap Index)
  • ARS CEAP watersheds (along with USGS NAWQA and NRCS CEAP)

Proposals under Development

LTAR Sites

Map of the 18 LTAR sites

ARS Experimental Watersheds and Range LTAR Sites
Site Name Site Code Location Established Record (years) Area (km2) Network Affiliation NEON Domain Major crops, land use, and livestock production Bibliographies
Archbold Biological Station Archbold Venus, FL/Ona, FL 1941 74 102 AmeriFlux, GLEON, NutNet, USCRN D3 - Southeast Beef cattle, pasture, rangeland, wildlife Short Bibliography
Long Bibliography
Central Mississippi River Basin CMRB Columbia, MO 1971 Up to 44 490 CEAP, SCAN D6 - Prairie Peninsula Grain cropping systems, some pasture, riparian forest Long Bibliography
Central Plains Experimental Range CPER Cheyenne, WY; Nunn, CO 1939 76 865 LTER, NEON, GRACEnet, NADP, NutNet, SCAN D10 - Central Plains Wheat-fallow, rangeland, beef cattle Long Bibliography
Eastern Corn Belt Columbus, OH 1974 Up to 41 N/A CEAP, GRACEnet D7 - Appalachians / Cumberland Plateau Cropland, swine, dairy poultry Short Bibliography
Long Bibliography
Great Basin GB Boise, ID 1961 54 239 CEAP, CZO, NADP, SCAN D15 - Great Basin Rangeland, beef cattle, wildlife Short and Long Bibliographies
Gulf Atlantic Coastal Plain GACP Tifton, Georgia; (Little River Experimental Watershed) 1965 47 334 CEAP, NADP, SCAN D3 - Southeast Cotton, peanuts, corn, vegetables (~50% irrigated); poultry, beef cattle Short and Long Bibliographies
Jornada Experimental Range JER Las Cruces, NM 1912 100+ 780 CEAP, COSMOS, LTER, NEON, NWERN, SCAN, UV-B MRP, USCRN, WNBR D14 - Desert Southwest Rangeland, beef cattle, wildlife Short Bibliography
Long Bibliography
Kellogg Biological Station KBS Hickory Corners, MI 1987 28 13 LTER, AmeriFlux, NADP, NutNet D5 - Great Lakes Row crops, forage crops, bioenergy crops, mixed grasses, prairie, forest, dairy Short Bibliography
Long Bibliography
Lower Chesapeake Bay Beltsville, MD 1910 22 2600 CASTnet, CEAP, COSMOS, EOS, NADP, GRACEnet, SCAN, UV-B MRP D2 - Mid Atlantic Cropland, poultry, dairy, forages, pasture, horticulture Short Bibliography
Long Bibliography
Lower Mississippi River Basin Oxford, MS 1981 Up to 34 21.3 COSMOS, CEAP, SURFRAD, SCAN D8 - Ozarks Complex Cotton, corn, soybeans, rice, catfish, sugar cane Long Bibliography
Northern Plains NP Mandan, ND 1912 100+ 9.7 NEON, CEAP, GRACEnet, REAP, SCAN D9 - Northern Plains Small grains, row crops, beef cattle on grazing lands Short and Long Bibliographies
Platte River/High Plains Aquifer Lincoln, NE 1912 100+ 16500 AmeriFlux, GRACEnet, REAP, SCAN D6 - Prairie Peninsula Cropland, rangeland, beef cattle, biofuels Short Bibliography
Long Bibliography
R.J. Cook Agronomy Farm Pullman, WA 1999 15 0.57 7 LTAP, GRACEnet, REAP, NADP, SCAN D15 - Great Basin Wheat, barley, pulses (peas, lentils, chickpeas) Short Bibliography
Long Bibliography
Southern Plains SP El Reno, OK 1948,1961 54 1,423 CEAP, COSMOS, SCAN D11 - Southern Plains Beef cattle, winter wheat, pasture, forages, prairie Short Bibliography
Long Bibliography
Texas Gulf TGC Temple, TX 1937 76 N/A CEAP, GRACEnet, NutNet, LTBE, SCAN D11 - Southern Plains Cropland, rangeland, pasture, remnant prairie Long Bibliography
Upper Chesapeake Bay University Park, PA 1968 47 1,127 CEAP, GRACEnet, SCAN D2 - Mid Atlantic Row crops, dairy, pasture, forest Short Bibliography
Upper Mississippi River Basin UMRB Ames, IA 1992 23 6,200 AmeriFlux, CEAP, GRACEnet, SCAN D6 - Prairie Peninsula Corn-soybean with livestock (swine, beef, dairy) Short and Long Bibliographies
Walnut Gulch Experimental Watershed WGEW Tucson,AZ 1953 62 150 Ameriflux, CEAP, COSMOS, EOS, GRACEnet, SCAN D14 - Desert Southwest Rangeland, beef cattle, wildlife Short Bibliography
Long Bibliography