Michael Blazier | 6/5/2019 4:31:29 PM
Dr. Michael Blazier
As you drive through the abundant forests of Louisiana, you’ll also see a lot of pastures. The soils of much of the state are well-suited for growing timber and cow-calf operations, and there are mature markets for forest products and cattle. It’s also possible to efficiently use land to integrate timber and cattle production, with several financial and ecological benefits as a result.
One form of integrating timber and cattle is called timber grazing. Timber grazing involves allowing cattle to graze on the natural vegetation under tree cover. To protect trees from cattle damage, the tops of the trees should be above grazing height when introducing the cattle. To promote ample vegetation for cattle foraging, the crowns of the trees should be spaced far enough apart to allow sunlight to the forest floor. The years prior to crown closure and years after thinning are good stages of tree development for timber grazing. Relatively frequent thinnings, such as five to 10 years between thinnings, promote continued vegetation in the forest floor, and prescribed burning on a three-year cycle can further enhance the quality and quantity of forages for timber grazing. Another great benefit of frequent thinning and burning for timber grazing is that habitat quality for wildlife, such as deer and turkey, is enhanced by these forest management practices.
Another form of incorporating timber and cattle is called silvopasture. With silvopasture management, improved forage grasses, such as bahiagrass or bermudagrass, are established and managed under trees to optimize cattle production. Silvopasture generally has greater cattle production potential than timber grazing because improved forage grasses can support more cattle per acre. Long-term studies of silvopasture at the LSU AgCenter Hill Farm Research Station found that 1.5 cows per acre could be supported by bermudagrass under loblolly pine.
Forests can be converted into silvopastures after thinning. Thinning should be a bit more aggressive than in a conventional thinning to facilitate more light to the forages. For example, a loblolly pine forest thinned at around age 12 to 15 years would be cut down to a target of 100 trees per acre. After thinning, the stand is sprayed with herbicide, prescribed burned and disked to prepare for planting. Bahiagrass can then be broadcast-seeded or bermudagrass-sprigged into the soil between rows of trees. Sprigging bermudagrass takes more caution than seeding bahiagrass to avoid stumps. Once forages are established, they are fertilized as typically done in pasture management. Weed control in the forages differs slightly than in pastures because 2,4-D herbicides for broadleaf weed control must be avoided in favor of triclopyr herbicides to avoid damaging trees. As the trees mature, they are thinned on a five- to eight-year cycle to maintain adequate sunlight for forage.
Pastures can also be converted into silvopastures. Within pastures, trees are planted on wider rows than conventionally done in forest establishment to facilitate adequate sunlight for forage and for sufficient spacing between trees to navigate with tractors and haying implements. For example, trees planted in rows 25 feet apart are good for silvopasture spacing. Trees within each row are spaced 6 feet apart to have adequate trees for thinning revenue. Subsoiling prior to planting is important for breaking up the grass root mat to foster seedling growth. Competition control around the tree seedlings is best applied as a 3- to 6-foot wide band along the tree rows to protect forage growth in the rows between the trees. Cattle can be introduced into silvopasture fields as soon as the tips of the trees are above grazing height. Before trees reach this height the alleys between tree rows are used for hay production. With today’s genetics, trees can be tall enough to avoid grazing damage in as little as two years for loblolly pine.
There are multiple benefits for comanaging timber and cattle. Long-term studies by Mississippi State University found that internal rates of return for silvopastures were 15%, whereas pine plantations and cow-calf pasture management had 13% internal rates of return. The diversification of products improves the land’s financial performance. It also optimizes the use of light, nutrients and water of the land. Trees provide an even distribution of shading that fosters cattle grazing throughout the day even in the hottest temperatures. Fertilization, burning and herbicides applied to foster forage production also enhance tree growth. Timber grazing and silvopasture management are truly synergistic management systems that are great management options for landowners that value timber and cattle.
— Michael Blazier is a professor at the AgCenter Hill Farm Research Station and in the School of Renewable Natural Resources.