RESIDUAL DRY MATTER

WATER QUALITY

CALIFORNIA VEGETATION

Weeds
Vegetation Classification
Restoring Native Grasslands
Monitoring Vegetation and Grazing
Ecological Sites & State-and-Transition Models

LIVESTOCK PRODUCTION

Forage Production and Quality
Annual Rangeland Grazing Management
Grazing Behavior and Livestock Distribution
Improving Forage Production
Irrigate Pasture and Forages

Residual Dry Matter

Main Points

Residual dry matter (RDM) is the old plant material (litter) left on the ground and usually measured just before the start of a new growing season.

Management based on RDM can be expected to provide a high degree of protection from soil and nutrient loss.

Maintaining high RDM tends to push species composition toward tall grass domination and low RDM tends to push species composition toward domination by filaree and other forbs.

RDM guidelines are used by local, state and federal agencies and organizations to assess the level of grazing during the previous growing season.

RDM is an indicator of the combined affects of the seasons forage production and disappearance due to grazing and other losses.

Regional RDM guidelines differ depending on canopy cover, slope and rainfall.

The comparative yield method can be used to rapidly measure RDM across large areas.

RDM can be mapped and the maps saved as an annual record of RDM.

Management Information

Bartolome J.W., W.E. Frost, N.K. McDougald and J.M. Connor. 2002. California Guidelines for Residual Dry Matter (RDM) Management on Coastal and Foothill Annual Rangelands. Rangeland Monitoring Series, University of California Ag and Nat Res Pub 8092. Oakland, CA. 8 p.

BLM (Bureau of Land Management) 1996. Sampling vegetation attributes. Interagency Technical Reference No. BLM/RS/ST-96/002+1730, Bureau of Land Management, Denver, Colorado. Pg 116-122.

Frost, W.E., N.K. McDougald, and W.J. Clawson. 1988. Residue mapping and pasture use records for monitoring California annual rangelands. UC Davis Range Science Report 17.

Frost, William E., Neil K. McDougald and Melvin R. George. 1990. Herbaceous plant measurements. In: Clawson, W.J. 1990. Monitoring California’s Annual Rangeland Vegetation. Leaflet No. 21468. Div. of Agric. and Nat. Res., Univ. of Calif., Oakland, CA. pgs 4-5.

Scientific Studies

Bartolome, J.W., M.C. Stroud, and H.F. Heady. 1980. Influence of natural mulch on forage productivity on differing California annual range sites, J. Range Manage. 33:4-8.

Bentley, J.R. and M.W. Talbot. 1951. Efficient use of annual plants on cattle range in the California foothills. U.S. Dep. Agric. Circ. 870. 52 p

Heady H. 1956. Changes in a California annual plant community induced by manipulation of natural mulch. Ecology 37:798-812.

Hedrick, D.W. 1948. The mulch layer of California annual ranges. J. Range Manage. 1:22-25.