NB_190_22_5 - NB 190-22-5 ECS – Determining Plant Lists of Desirable Species for PCS and DIPH Assessments for Each State
NB 190-22-5 ECS – Determining Plant Lists of Desirable Species for PCS and DIPH Assessments for Each State
National Bulletin: 190-22-5 Date: December 17, 2021
Subject: ECS – Determining Plant Lists of Desirable Species for Pasture Condition Score (PCS) and Determining Indicators of Pasture Health (DIPH) Assessments for Each State


Purpose.  A nationwide list of forage species known to meet the definition of desirable species relative to PCS and DIPH assessments is provided to assist States in developing their own lists.   


Expiration Date.  September 30, 2022


Background.  Individual State lists of desirable species will improve assessment quality of PCS and DIPH and ensure quality control for National Resource Inventory summary analyzes. These protocols are also used for planning and in the Conservation Assessment Ranking Tool.


Explanation.  The attachment contains a nationwide list of forage species that meet the definition of desirable species. If States have a detailed list of desirable species, the attachment does not replace it. However, if States are developing or updating their lists, they may use the list of desirable species relative to the PCS/DIPH protocols to build or revise their own lists. States should use the definition stated below, as defined in NRCS Guide to Pasture Condition Scoring, when identifying desirable species.

DEFINITION –Desirable species are readily consumed, persistent, and with sufficient fertility to provide high tonnage and quality for a significant part of the growing season. Some forage species may be listed as intermediate if they do not produce significant yield, have severely diminished quality in late phenological stage, or are considered a nuisance species in pastures. Intermediate forages may be desirable for different classes of livestock.

A forage that is a desirable forage species in one State may be on the noxious weed list in another State. Follow your State’s noxious weed policy and use the NRCS PLANTS Database (https://plants.sc.egov.usda.gov/home) for locality information.

The attachment is a reference guide for livestock grazing herbaceous and woody forage species. The worksheet has tabs for functional groups of grasses, forbs, legumes, and woody species. Each tab contains species ID, scientific and common names, lifespan, and nativity. Some species will show a constancy rating that indicates its common presence as a percentage of the total lists reviewed.

For those States that have completed lists including five levels of species preference for numerous herbivores, their lists should be maintained and used in local State technical guidance. In addition, those States may want to check their list’s species code with the list of desirable species in the attachment. For those States that do not have complete lists, select plants from the list as needed. For example, cattle and sheep diets differ in preference for the forbs Lespedeza cuneata and Symphyotrichum ericoides; cattle generally avoid consuming these forbs while sheep prefer them. Add species only when local knowledge of a specific plant/animal preference combination occurs and meets the definition as described above. DO NOT include other values into the definition of desirable species used in these pasture assessments. Archive the attachment after the State list is developed.

Distribution. This national bulletin is available on the NRCS Electronic Directives System website at http://policy.nrcs.usda.gov, while the technical document is accessible through the NRCS Range Resources website at https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/landuse/rangepasture/range/.

Filing Instructions. Due to printing and distribution costs, the availability of this information is limited to electronic format (with limited paper distribution). If a paper copy is retained, file it sequentially within Title 190, Ecological Sciences, of the Technical Note binder.


Contact.  For further information, contact Tom Hilken, National Grazing Land Specialist, Ecological Sciences Division, by telephone at (202) 720-5010 or by email at thomas.hilken@usda.gov.



J. Xavier Montoya
Acting Deputy Chief for Science and Technology

Attachment:  Worksheet-Species List
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