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Interpretation of Organic Matter Levels in New Jersey Soils

COVID-19 UPDATE (7/8/21)

Rutgers Soil Testing Laboratory staff are still at work, providing fee-for-service analysis of soil samples and generating reports/recommendations for all clients. Appropriate safety procedures and precautions are being followed to assure and protect the health of staff, including social distancing and use of personal protective equipment. Public access to the Soil Testing Laboratory will remain limited until further notice.

How to Get Soil Tests?

Soil test kits may be available for purchase locally depending on county-level policy relating to access to offices of Rutgers Cooperative Extension. Please contact your county office of Rutgers Cooperative Extension to find if soil test kits are available for purchase there.

OR

Visit our page How to Get Your Soil Tested, and find the appropriate Soil Sampling Instructions and Soil Test Questionnaire for your situation; see headings for different land use and crop scenarios. Read and follow the instructions; download and fill out the questionnaire; then send soil sample and questionnaire with payment to the lab by mail or delivery service, or drop off sample/questionnaire/payment at the lab as described below.

Sample Drop Off at the Soil Testing Lab

As of July 6, 2021 soil samples may be dropped off at Rutgers Soil Testing Laboratory using the side entrance of Rutgers’ Administrative Services Building II (glass door on southwest side of the building) under these conditions:

  • Paperwork (soil test questionnaires) should be filled out in advance and accompany soil samples, inside a bag or box with samples.
  • Drop-off location is the southwest entrance/foyer of ASB-II. The glass door at this entrance is labelled: "Equine Science Center/Information Technology Services/Soil Testing Laboratory."
  • Soil sample drop-off time is 7 a.m. to 12 noon, Monday through Friday.
  • Note: Face masks are mandatory in Rutgers buildings.
  • Enter and remain in the foyer; the office and lab doors remain closed to the public. However, the side entrance and foyer can be seen from the inside main office of the Soil Testing Lab.
  • Get the attention of office staff through the window or call (848-932-9295) so that staff come to foyer to take sample(s) and paperwork immediately.
  • Do not leave any paperwork with credit card information or other payment unattended. If no-one is able to answer your call immediately, sample(s) with identifying information can be left in the foyer, and paperwork/payment will be attended to remotely.
Organic Matter Soil Texture
% Loamy Sand Sandy Loam Loam Silt Loam
Less than 0.5% Very Low Very Low Very Low Very Low
0.5 to 1.0% Low Very Low Very Low Very Low
1.0 to 1.5% Medium Low Very Low Very Low
1.5 to 2.0% High Medium Low Low
2.0 to 2.5% Very High High Medium Low
2.5 to 3.0% Very High Very High Medium Medium
3.0 to 3.5% Very High Very High High Medium
3.5 to 4.0% Very High Very High High Medium
4.0 to 5.0% Very High Very High Very High High
More than 5% Very High Very High Very High Very High

Notes

Soil textures finer than those listed (clay loams and clays) can be evaluated using the "silt loam" column.

Organic matter values are expressed as percentage by weight basis. The value accounts for soil humus and easily oxidized organic fractions of the soil but may not include unreactive fractions.

Although organic matter would include anything organically-derived, samples are sieved to remove gravel (>2mm), which may also remove particulate organic matter as well, including sticks and roots.

Organic matter content is a dynamic soil property, strongly influenced by management and affected by environmental conditions as microorganisms continue to decompose the organic matter and release nutrients.

While organic matter is a valuable soil component for chemical, physical, and biological reasons, amending soils to organic matter content greater than 10% is not recommended for general use as plant growth media.