Soil Samples

Soil samples are collected at NEON sites for a number of NEON applications.  Members of the science community have expressed interest in gaining access to some of these samples for research purposes.  Making these soil samples available to the greater scientific community is fundamental to the NEON mission and is expected to contribute to ecological research for site to domain to continental scales in the near term and over several decades. NEON collects the soil samples listed in the table below.

What samples are available now?

NEON Soil Collections

Sample Horizon Processing Storage Conditions Volume/ Mass Stored Sampling/Frequency Locations/Site Get Samples
Soil Mega-Pit Multiple Air-dried, mineral soil sieved to ≤ 2mm   Ambient temperature, glass jars 1.2 or 3.6 kg; each horizon 1; 1 year only 1 Request now
Excess Soils Organic layer; mineral soil to 30 cm None Temporary-monthly; ambient, dry cabinet Highly variable due to processing <0.3L per core sample As above for Microbial and Physcial and Chemical Measurements 90-144 Request now
Distributed Baseline Soil Collection Multiple Air-dried, mineral soil sieved to ≤ 2mm Ambient temperature, cardboard pints 1 pint; each horizon 1; 1 year only 10-40 Currently not available
Soil for Microbial Measurements Organic layer; mineral soil (total soil core depth is 30 cm) None Frozen at -80 C 50 ml Monthly for first 2 years; 3 time per year thereafter 90-144 Currently not available
Soil for Physcial and Chemical Measurements Organic layer; mineral soil (total soil core depth is 30 cm) Air-dried, sieved to ≤ 2mm Ambient, dry cabinet (1) 20 ml; (2) 200g Once every 10 years 10-15 Currently not available

Soil Mega-Pit Archive - Now Available!

Learn more about the Mega-Pit Soil Archive or request Soil Mega-Pit samples here

Soils are collected from multiple soil horizons at one soil pit at each NEON site. These archived soil samples serve as a reference of soil physical and chemical conditions at the time the NEON site was constructed and are generally collected once per site from a pit that is up to 2 m deep at most sites.  Initially, a total of 1.2 kg of soil was archived from each horizon; however, as of June 2014 this was increased to 3.6 kg for all future soil pits to meet anticipated demand.  As of July 2013 the soil archive contains samples from 14 different NEON sites representing 7 soil orders. The archive is growing steadily, with soil from additional NEON sites being added on a regular basis. Soils from all 60 NEON terrestrial sites are projected to be archived by 2016.

Excess Soils

Excess soils may remain after soils are fully processed for physical, chemical and microbial measurements.  The amount available in any given month will vary depending upon analytical needs for soils during that month; amounts will also vary across sites and years.  NEON does not plan to archive these soils.  However, we may be able to make excess soil available to the research community in an ad hoc fashion and on a first-come-first-serve basis. To request excess soil samples, please contact the Soil Archive team.

Distributed Baseline Soil Collection

NEON requires detailed field characterization and laboratory analysis of soils at each observatory site.  The field characterization work is required to inform site-specific soil sampling protocols and data analysis, and the laboratory analyses contribute to a required set of Level 0 data products.  Between 10 and 40 soil pits or cores (up to 1 m depth) will be sampled once at each NEON site to characterize the variability of soil chemical and physical properties within the NEON permitted site boundary. NRCS will fill one pint-sized container with a subsample from each soil horizon for inclusion in the Kellogg Soil Survey Laboratory, Natural Resources Conservation Service (NRCS), located in Lincoln, NE.  NEON will not maintain a separate set of archived samples.

Soil for Microbial Measurements

Soils are collected at tower and distributed plots at each NEON site to characterize soil microbial biodiversity and function. The maximum total depth of each soil core is 30 cm.  Organic and mineral horizons are separated prior to analysis; other horizons are not.  For the first two years, sampling occurs once per month (except when the ground is frozen) for microbial analyses – this includes 4 plots at 3 cores per plot.  Thereafter, samples are collected 3 times per year for microbial analysis – 10 plots at 4 cores per plot. A frozen subsample will be saved in a 50 ml vial for archiving purposes.

Soil for Physical and Chemical Measurements 

Soils are collected at 10-15 tower and distributed plots at each NEON site to characterize soil physical properties and nutrient stocks. The maximum total depth of each soil core is 30 cm.  Organic and mineral horizons are separated prior to analysis; other horizons are not. For physical and chemical analyses, sampling takes place once during the growing season concurrent with sampling for microbial analysis – samples are collected only once every 10 years.  A sieved oven-dried, pulverized subsample is saved in a 20 ml scintillation vial for archiving purposes.  In addition, a 200 g sieved (≤ 2mm) air-dried subsample is saved for archiving purposes.