Tag: pasture

Stockpiling Pasture for Fall and Winter Grazing

Amanda Grev, Forage Specialist
University of Maryland Extension

It’s August now and whether or not we’re ready cooler temperatures are just around the corner and it’s time to be thinking about winter feeding strategies.  Using harvested forages for winter feed represents a substantial expense for livestock operations.  For many grazing operations, stockpiling can be an effective strategy to extend forage resources further into the fall and winter season, reducing the costs associated with harvesting and storing feed and providing high-quality pasture for fall and winter grazing.

What is stockpiling?

The concept of stockpiling is simple.  Rather than cutting, drying, and storing hay to feed over the winter, existing pastures are allowed to grow and accumulate forage in the field to be grazed by livestock in a later season.  Under this management strategy, grazing animals are removed from pastures in late summer and forages are allowed to accumulate growth through the late summer and fall.  The cool, late-season temperatures make it possible for the accumulation of high-quality forage even after an extended period of growth.  This stockpiled forage is then available for grazing throughout the fall and winter months, reducing the costs associated with feeding stored feeds.

Which forages work best?

Although a number of different forages can be stockpiled, some forage species will hold their nutritional value longer than others in the winter months.  Compared to other cool-season grasses, tall fescue is well adapted for stockpiling, as it has the ability to accumulate a substantial amount of fall growth and tolerate colder temperatures without losing quality.  In addition, the waxy layer or cuticle on the leaves of tall fescue make the plant more resistant to frost damage or deterioration.  Tall fescue also forms a good sod, making it more tolerant to foot traffic and minimizing impacts on its productivity the following season.

How is stockpiling accomplished?

Early August is the time to begin stockpiling for fall and winter grazing.  To prepare for stockpiling, pastures should be grazed (or clipped) down to a 3 to 4 inch stubble height to ensure that the accumulated forage will come from new growth.  After livestock are removed, 40 to 60 pounds of nitrogen fertilizer should be applied to stimulate additional regrowth and optimize forage accumulation and quality.  The grasses should then be allowed to regrow until forage growth dramatically slows or ceases completely.

It should be noted that not all nitrogen fertilizers will be equally efficient when fertilizing pastures in the fall.  In urea or urea-based fertilizers, the ammonia is volatile and a substantial amount of the nitrogen from these sources will be released to the atmosphere via volatilization when applied during the hot and humid days of late summer.  To minimize this volatilization, these nitrogen sources should be applied immediately prior to a significant rainfall event.  Ammonium nitrate is the most efficient source of nitrogen for stockpiling, but it is often more expensive than other sources.

Will yield and quality be good?

Where tall fescue was successfully stockpiled, yields of 1 to over 1.5 tons of dry matter per acre have been documented.  Higher yields will be achieved if nitrogen is applied immediately after the last cutting or grazing compared to pastures that did not receive fertilization or were fertilized later in the fall.

Forage quality of stockpiled tall fescue can be very good.  Depending on how much nitrogen has been applied, fall-grown tall fescue can average 12 to 18% protein and maintain good nutritional value throughout the fall season.  Research has demonstrated that stockpiled tall fescue has sufficient quality to carry dry cows through the winter and could carry lactating beef cows into January without additional supplementation.  However, the forage quality and digestibility of stockpiled forages is variable and will decline as growth accumulates, forages mature, and winter conditions continue.  To confirm nutritional value, forage samples should be taken and analyzed to ensure the pasture is meeting the nutritional requirements of the animals utilizing it.

How to utilize stockpiled forage?

Stockpiled forage can be valuable under a variety of grazing methods, but forage utilization can be increased substantially by using improved grazing practices.  If livestock are allowed to continuously graze the entire pasture with unrestricted access, efficiency will be lower and the potential grazing period will be shortened due to waste and trampling damage.  To minimize waste and get the most from stockpiled forage, pastures should be either rotationally or strip grazed.  Strip grazing is a management system that involves giving livestock a fresh area of pasture every day or every few days by moving a temporary electric fence in the pasture.  This method limits the area available for grazing, helping to increase pasture carrying capacity and maximize forage utilization.

Summary

Removing livestock and fertilizing pastures or hayfields in late summer will allow forage growth to be stockpiled for late fall and winter grazing.  Utilization of stockpiled pasture is an economically-advantageous management strategy that will extend the grazing season, minimize winter hay feeding and stored feed requirements, and provide high-quality forage without negatively impacting the persistence of forage stands.

Summer Grazing Management

Amanda Grev, Forage Specialist
University of Maryland Extension

As we move into the traditionally driest, hottest days of summer, we can expect growth rates of cool-season grass pastures slow dramatically and pasture productivity to decline. However, there are management practices that producers can implement to maximize plant growth during these hot, dry spells.

It takes grass to grow grass.

The key to having productive pastures is optimizing plant photosynthesis. Think of your pasture as a solar panel where green, growing leaves are energy producers. To maximize production, livestock need to be rotated off of a pasture in a timely fashion to ensure an effective “solar panel” or leaf area is left in the paddock following grazing. Most cool-season forages need at least 3 to 4 inches of post-grazing residual to effectively take advantage of photosynthesis for regrowth. In addition to providing a photosynthetic base for plant regrowth, the leaf material that remains after a grazing bout also shades the soil surface, keeping soil temperatures cooler and helping to reduce soil moisture loss.

Removing leaf matter affects the roots as well, as those roots rely on the leaves to supply energy from photosynthesis. The amount of live growth occurring below ground is roughly equivalent to the amount of live growth occurring above ground, and research has shown that the amount of above ground forage mass removed impacts root health. Up to 50 percent of the plant can be removed with little to no impact on root growth. With greater than 50 percent removal, root growth slows dramatically, and removing 70 percent or more of the above ground forage mass stops root growth completely. This is where the old rule of thumb “take half, leave half” comes into play. Leaving half of the leaf area on the plant has minimal impacts to the plant root system, enabling the plant to continue to absorb nutrients and moisture and recover quicker following grazing. If the take half, leave half rule is violated and pastures are grazed too low, plant root growth stops and root reserves are used to regrow leaf tissue, diminishing the vigor of the plant root system and the overall productivity of the plant.

Provide a rest period.

One of the most common mistakes in grazing management is not providing a long enough recovery period for pastures after g razing. Pasture forages require a rest period in order to maintain vigorous production. When a plant is grazed, the loss of leaf material means the plant loses its energy-producing center. The plants’ response is to rebuild that center using stored energy reserves. If the plant is given rest following grazing, new leaves will develop and will replenish this energy supply. Without rest, the plant is not able to replenish its energy supply and will continue to use the remainder of its stored energy to produce new leaves. As energy supplies are depleted, the plant will be unable to maintain production and will eventually die, leading to weak stands, overgrazed pastures, and the invasion of weeds or other non-desirable forages.

Maintaining flexibility in your system will allow you to balance the length of the rest period with the plant growth rate and is fundamental to successful grazing management. How long recovery takes will depend on a number of things, including the plant species, grazing pressure, and the time of year. As we get hotter and drier, grass growth rates will slow down and the days of rest required may be much longer than that required during the spring when rapid growth is occurring. Regardless, the rest period must be long enough to allow the plants to recover and grow back to a practical grazing height before livestock are allowed to graze again; for most grasses, this height falls in the 8 to 10 inch range.

To accommodate for this longer rest period, the rotation speed between paddocks will have to slow down. The basic rule is: when pastures are growing fast, rotate fast; when pastures are growing slowly, rotate slowly. Remember that the goal of the rest is to allow young green leaves to maximize photosynthesis.

Don’t ignore seed heads.

A plant that is producing seed heads is undergoing reproductive growth and not putting energy into leafy growth or tiller production. Clipping seed heads from these grasses will allow the plant to return to leafy or vegetative growth, which will increase forage quality and result in more total forage being produced over the course of the season. Clipping will also serve the added benefit of helping to control weed populations.

Seed heads can also be an indication of uneven grazing patterns in your pasture. If selective grazing is occurring, some plants are likely being overgrazed while others not enough. If this is happening, consider adding more divisions or paddocks into your pasture system. This means you will be grazing your animals on smaller areas, increasing the stocking density. A greater stocking density will reduce the amount of selective grazing that occurs, increasing forage utilization and reducing the need for pasture clipping.

While we can’t control how hot or dry summer will get, we can strategically manage the grass we have to help keep summer paddocks productive and growing.

New UMD Pasture Management Specialist

Meet Dr. Amanda Grev! Amanda joined the University of Maryland Extension team in January and serves as the new Pasture Management Specialist. A native of Rochester, MN, Amanda completed her undergraduate degree in Animal Science at North Dakota State University, followed by a research internship at Kentucky Equine Research in Versailles, KY. Amanda received her M.S. and Ph.D. in Animal Science from the University of Minnesota, where her research focused on the interaction between animal nutrition, forages, and pasture management. Her office is located at the Western Maryland Research & Education Center in Keedysville.

Learn more about Amanda on our faculty directory webpage, https://agnr.umd.edu/about/directory/amanda-grev. Amanda can be reached by phone at (301) 432-2767 or by e-mail at agrev@umd.edu.