Optimizing Grazing Management

Definition

Grazing management refers to the manipulation of animal grazing to achieve optimum and sustained animal, plant, land, environmental or economic results while ensuring a continuous supply of forages to grazing animals.

Purpose

Maintain a healthy and productive pasture to ensure the full productive potential of grazing land.
Reduce soil and nutrient losses in the runoff, thus maintaining the physical and chemical fertility of the soil and preventing water quality deterioration.
Efficiently utilize rainfall by increasing infiltration and reducing surface runoff from the soil.
Maintain higher soil organic matter, thus preserving soil health that will ensure efficient cycling of soil nutrients.

How Does This Practice Work?

Most phosphorus (P) loss from grazing systems occurs through surface runoff, which carries both dissolved and particulate forms of P to surface waters. As surface water bodies become enriched with P, overall water quality deteriorates. An efficient grazing management system will reduce the loss of soil particles in surface runoff by providing good vegetative soil coverage with appropriate grass/legume species that promote the physical entrapment of eroded soil particles and particulate-bound nutrients. These practices will result in less loss of sediment to water bodies.

Additionally, increased water infiltration will reduce surface runoff, reduce dissolved P loss, and maintain higher soil moisture for optimum pasture growth. Increased organic matter content due to continuous vegetative coverage of the soil will also help to maintain optimum conditions for soil microflora and good soil structure.

Where This Practice Applies and Its Limitations

Grazing management is a necessity for native/indigenous vegetation and established pastures. The specific grazing management practices will:

use the right mix of grass or legume species
encourage more uniform use of paddocks
manage stocking rates over time
adjust the timing or season of grazing
integrate with winter hay feeding.

In some pasture areas, P losses can peak in the winter when farmers repeatedly feed hay in the same area, often referred to as a sacrifice paddock. Stockpiling fescue, and/or rotational bale grazing are more beneficial to minimize P loss. The grazing management plan needs to provide drinking water for the animals away from vulnerable water bodies to prevent potential pollution from animal traffic and direct deposit of manure. Land condition, quality and quantity of forages and rainfall are the important factors to consider while establishing a new grazing pasture.

Continuous grazing with higher stocking rates can result in soil compaction, reduce rainfall infiltration, and cause offsite P transport in surface runoff pathways.

A challenge for grazing management is to maintain the stocking rate (animal numbers), adjust the timing of grazing or rotational grazing, and prevent pasture decline associated with the replacement of productive species by undesirable weeds.

Effectiveness

Erosion and surface runoff can be greatly reduced by adequate year-round soil coverage by grasses and legumes, which prevents soil compaction. The good pasture growth will increase infiltration, thus reducing runoff and entrapping the soil particles from being lost from the pasture. Reduced runoff and erosion and increased infiltration can effectively decrease the edge-of-the-field P loss to surface water.

Cost of Implementing the Practice

Approximately 50 percent of land area in the U.S. is grazed. This includes 5-10 percent of pastureland that may need reseeding after a few years of intensive production, depending upon the grass/legume species. The cost of establishing an improved pasture includes seedbed preparation, seed, planting, commercial fertilizers, water supply and fencing. Most grazing lands use native grasslands, which, together with perennial pastures, may require minimum costs for establishing a new pasture every year. The annual costs connected with killing the vegetation for the preparation of succeeding crops are negligible in pastures. There are net gains with grazing lands compared to a confined animal feeding system in terms of reduced housing, reduced forage handling, reduced manure handling and the associated transport costs.

Operation and Maintenance

Establishing a new grazing pasture requires selecting a mix of good grass or legume species. The soil needs to be seeded at an adequate density to ensure maximum soil coverage and prevent/reduce erosion. Efficient weed control is a necessity for both native and established pastures to prevent the invasion of weeds and pests. Good management that adjusts the stocking rates and timing of grazing pasture is extremely important to ensure that the benefits of grazing are reaped while protecting soil and water quality.

References

Strickler, D. 2019. Managing Pasture: A Complete Guide to Building Healthy Pasture for Grass-Based Meat & Dairy Animals. Storey Publishing, North Adams, MA.

Heitschmidt, R. K. and J. W. Stuth, 1991. Grazing Management: An Ecological Perspective. Timber Press, Portland, OR.

Vallentine, J. F. 2001. Grazing Management. 2nd Edition. Academic Press, London.

For Further Information

Contact your local soil and water conservation district, USDA-NRCS or Cooperative Extension Service office. To find your local USDA Service Center, visit https://www.nrcs.usda.gov/contact/find-a-service-center.

Current Authors

G.S. Toor
University of Maryland
gstoor@umd.edu

R.O. Maguire
Virginia Tech
rmaguire@vt.edu

Previous Author

Tom Sims
University of Delaware

Editing and Design

Deanna Osmond
NC State University

Forbes Walker
University of Tennessee

Citation:

Toor, G. and R. Maguire. 2023. Optimizing Grazing Management. SERA17 Phosphorus Conservation Practices Fact Sheets. https://sera17.wordpress.ncsu.edu/optimizing-grazing-management/