Pastures are complex biological systems that consist of sun, soil, water, plants, and animals. To be an effective pasture manager, think of yourself as a grass farmer. The forage is the crop and the grazing animals are the harvesters. A healthy pasture provides nutritious forage that will improve the livestock’s ability to thrive and resist disease. Proper grazing avoids compaction, improves soil structure, increases organic matter, decreases erosion and increases infiltration, thereby improving water quality and soil health. These conditions contribute to plant vigor and improved root structure. Healthy forage inhibits weed invasion and reduces the need for pesticides. Properly grazed pastures provide wildlife habitat during pasture rest periods. Improve or protect the health of your pasture to increase the property’s value and reduce the amount of polluted runoff that leaves the land.
Continuous grazing should be avoided. Animals that are allowed to roam the entire property will choose the type of forage they want to eat. Since they prefer the new, tender forage, continuous grazing leads to exhaustion of good forage species, proliferation of weedy species, and development of muddy bare patches. A better method is rotational grazing, where pastures are subdivided and animals are frequently rotated to allow forage to rejuvenate. Temporary electric fencing is a low-cost way to subdivide the pasture into paddocks before you invest in permanent cross fences. When grass production will not support your animals, move them to an all-season pen and provide supplemental feed. See Mud Management Sections for heavy use area details. Minimize compaction: do not graze pastures in wet winter months. Compacted soil restricts root growth and prevents water from moving into and through the soil to the roots. Provide adequate drinking water for animals. Have water, salt and minerals strategically located to distribute livestock evenly across pastures. Fence off streams so that manure and other pollutants are kept away from water resources. Set up grass and tree buffers along stream/ river banks to prevent erosion. Avoid soil disturbance, which can activate previously dormant weed seeds and compromise soil health.
Grazing Height Rule of Thumb
To maintain healthy grass pastures and livestock, a general rule of thumb is to manage grass height so that it ranges between two to eight inches high. Rotate grazers into paddocks when grass is six to eight inches high and out when grass is two to three inches tall. These management heights vary by grass species and season. Plants are overgrazed when carbohydrate reserves are continually depleted without enough time for the plant to replenish its stores. Overgrazing reduces root development so plants can’t effectively access water. Proper grazing height optimizes animal nutrition and minimizes threats of parasites.
Signs of Good & Poor Grazing Management
Good Management: Animals confined to winter use area when pasture is wet. Large pastures subdivided into smaller pastures. Animals fenced out of streams. Water provided in each pasture. Presence of a vegetative buffer between streams and pastures. Forage is never less than 2-3 inches in height.Bad Management: Bare ground filled with weeds. High browse lines on trees and shrubs. Trampled stream bank. Animals grazing through the fence. Livestock on wet soil. Animals ankle deep in mud or manure.
Proper irrigation can help improve a pasture’s productivity. Pastures with healthy plants will be able to access deeper water reserves. Daily plant water requirements vary based on factors such as air temperature, solar radiation, day length, wind, and growth stage of the plant. The Agrimet Crop Water Use Program predicts water use or evapotranspiration (ET) on a daily and weekly basis. OSU Extension Service, NRCS and Benton SWCD can provide information on irrigation principles and management. Irrigate pastures following grazing rather than prior to grazing.
Pasture plants need nutrients, such as nitrogen, phosphorus, potassium, and sulfur to grow properly. Balanced grazing prevents the concentration of soil nutrients within the pasture; therefore a fertility plan should be developed. Test the soil to determine nutrient and pH levels and apply amendments every three to four years. Adjust animal numbers and management based on pasture production and regrowth.