Grazing Management: Are you stacking the deck? Basic forage managment

Are you managing for undesirables in your pastures?

by:  Stuart Gardner, USDA NRCS Range and Pasture Resource Management Specialist 

                     Lafayette, Louisiana

Are you guilty of stacking the deck? Is overgrazing occurring in your pastures? With most desirable forage plants there is generally only as much active root below ground as there is active plant above ground.  When more than 50% of the desirable forage plant by weight is removed, roots begin to die off or become inactive.  When this occurs on a regular basis the plant loses vigor.  As the plant loses vigor it loses it’s ability to compete with other plants for sunlight, and to gather water and nutrients from the soil. At the same time, the desirable plant's ability to make food through photosynthesis is greatly reduced or nearly halted because of the excessive removal of the leaves.  With the majority of its leaves removed and having had a reduction in the amount of functional roots, the desirable forage plant is put at a huge disadvantage. By allowing this to take place, the manager has “Stacked the Deck” against the desirable forage plants! Also, dry conditions effect plants with shallow root systems first. Overgrazing is the term used to describe this scenario. 

Properly applied grazing management has become a serious point of focus for cattle producers who are serious about success. Reduction of input cost by spending as many days as possible grazing has become a necessary survival strategy. Input costs such as hay, supplemental feed, diesel, labor, equipment, pesticides, seed, lime, insurance, etc., have skyrocketed in the last 4 years, and are not likely to go down. The price of cattle has not risen to a level that will offset these high cost of operation. Even at today's 2025 high calf prices, input cost are the biggest challenge.

Grazing management is something that is a common sense approach. It can be beneficial to all producers, regardless of the size or scope of their ranching operation or level of experience as a cattle producer. Grazing management is the manipulation of grazing animals to accomplish a desired result.  Maintaining a stand of desirable forage is a goal or desired result, which can be achieved through properly applied grazing land resource management.  Wise and efficient use of natural resources can be accomplished.  Good grazing management leads to improved utilization of existing forages and natural soil fertility, an extended grazing season, and less dependency on costly supplements and hay.

Rotational grazing has become an important part of many cattle producers’ pasture management programs. Basic rotational grazing is the planned movement of a herd of grazing animals through a series of pastures. Pastures are generally grazed for a period of 3 to 8 days then rested for a period of 3 to 4 weeks. A minimum of 4 to 6 pastures is required to implement this practical method of grazing management effectively. As producers consider and begin to implement grazing management or controlled grazing, they begin to understand the practical elements that make it a sound management tool.  With controlled grazing, the decision maker decides when and where the cattle graze.  Under traditional continuous grazing systems, the cows make the decisions.

Applied grazing management may not be for every ranch manager.  Like most management inputs that have positive long term benefits, learning to practice grazing management effectively takes though, time, effort, and execution. Learning how to manage a dynamic pastureland ecosystem is a task that is not for the weak-hearted.  The benefits of successfully applied grazing management can be very substantial. 

First, one has to realize what is occurring in a pasture that is grazed continuously throughout the year or overgrazed for a period of time.  In a continuously grazed or overgrazed pasture the more desirable forage plants are sought out by the cattle and are grazed over and over again.  Although the desirable forage plants are fast growing and aggressive under normal conditions, they start to lose ground to less desirable forage species and weeds that the cattle do not like to graze. These are plants such as smut grass, carpet grass, briars, and tallow trees. As the desirable plants do their best to re-grow, they struggle, because as they attempt to grow they get grazed again and again. Leaves and roots become diminished, and the desirable forages, are severely weakened.  The cattle are seeking the most nutritious forage in the pasture and this re-growth is just that.  If continuous grazing pressure persists over time, the more desirable plants in the pasture eventually die out or become a very small part of the plants in the pasture.  The desirable forages are eventually replaced by less desirable forage species and weeds.

The undesirable plants in the pasture that are present take advantage of this situation. Because of lack of grazing use, the undesirable plants have developed extensive root systems and have many leaves.  The undesirable plants have the tools that they need to thrive.  The desirable plants have very little chance to sustain the stand or even survive under these conditions.  The deck is stacked against them!  As the desirable plants lose vigor and become stressed, the undesirable plants “hog up” a majority of the available sunlight, water, and nutrients. In many cases a complete stand of desirable forage is replaced over time with undesirable forages and/or weeds.  

Low pH and poor soil fertility conditions can speed up this process or declining pasture trend.  Maintaining good soil pH and soil fertility will slow down the trend towards dominance by less desirable forages and weeds, but the grazing management regime is the driving factor in the system!  Herbicides are also typically used in an attempt to eliminate undesirable plants in a pasture.  This course of action can be used to treat the symptoms of a declining pasture trend in a system. It rarely, solves the problem for the long-term. Good, continuously applied grazing management is the key to sustaining a good healthy stand of desirable forage.

Many cattle producers spend good money, time, and effort on renovating a pasture.  The pasture is worked up, limed, fertilized, and planted to a more desirable forage species, only to then place the livestock in the renovated pasture on a continuous basis. The issue that caused the negative change in vegetation was not addressed. The pattern repeats!  Unfortunately, usually 2 to 5 years after the renovation, the pasture reverts back to its original undesirable plant composition.  The continuous grazing pressure or overgrazing, has forced the pasture to revert back to the less desirable forage species and weeds.  The old saying, “If you do what always done, you’ll get what you always got”, applies to this set of circumstances.  A typical situation would be where bermudagrass, or even bahiagrass, is replaced in a pasture by an undesirable forage species, such as carpetgrass and smutgrass.  Carpetgrass can survive and thrive under continuous or heavy grazing pressure.  A plant such as carpetgrass can survive because of the low growth form that it has.  The growth points are so low to the ground that a cow cannot graze them off. It can also tolerate poor drainage, low pH and soil fertility.  The undesirable plant is there mainly because of the conditions maintained in the pasture under continuous grazing or overgrazing.  

Basic rotational grazing is a simple method that allows desirable forage plants fair opportunity to grow and prosper in grazed pastures.  By allowing a grazed plant time to rest and re-grow before being grazed again you give the desirable forage plant opportunity to survive, thrive, sustain, and even increase in composition.  If given a fair opportunity, most desirable forage species are aggressive and very competitive for sunlight, water, nutrients, and space.  Most desirable forage species in the south require 3 to 4 weeks rest between grazing periods under normal circumstances.  The length of rest periods will vary depending on your location, rainfall, season, and plant species, as well as other factors.   A very common error made by those managing rotational grazing systems is to turn cattle in on pastures that are over-mature, and of low quality.  A pasture that has been rested longer than 3 to 4 weeks is generally past its prime for quality.  Simply skip that pasture and move on to the next one that is less mature and higher in quality. Excess forage can usually be harvested as hay, or stockpiled for grazing use during the dormant season. 

A 2 to 4 inch minimum grazed height is adequate for most forage species in the south.  Rotate on to the next pasture when this minimum average height of the desirable forage is reached. Mowing immediately after every other grazing period is also recommended.  This vegetative management practice clips off un-grazed or lightly grazed plants and insures that all pasture plants have to compete under similar harvest pressure.  When using this management technique a minimal amount of material will have to be mowed.  The cattle will have grazed off everything that they wanted. By strategically mowing at this time the wear and tear on equipment and time requirements will be reduced.  When this is done on a regular basis at the proper time the effects are obvious and very beneficial to maintaining or increasing a stand of desirable forages.  This is one practice that allows the manager to level the playing field and avoid stacking the deck against the desirable forages.

Please take the time and make the effort to think about the explanation of the effects of continuous grazing and overgrazing. The information and insight provided in this article is based on sound logic, common sense, scientific principles of plant and animal interaction, and experience. After reading through this explanation, you may begin to understand some of the main reasons that many cattle producers are using rotational grazing. The southern and southeastern United States is generally blessed with adequate rainfall (in most years), moderately fertile soils, and a climate that is well suited for year-long forage production. These climatic factors along with good practically applied grazing land resource management may just be our secret weapon or the needed “unfair advantage” that we have in the beef production business. These attributes allow us to realize desirable responses from properly implemented grazing management.  There are many other factors that can have an effect on pasture plant composition. Some of the many factors are: soil fertility, stocking rate, soil type, pH, type of livestock grazed, and drainage. Although each of these is very important, the main driving factor for grazing lands is the grazing management regime! That is something that can be controlled, by you, the manager.

Development of a comprehensive conservation plan is recommended.  A custom grazing plan is a part of this plan.  Assistance is available to private land owners and managers from the local Soil and Water Conservation District and the USDA Natural Resources Conservation Service Field Office in your parish.