Integration of pines, pastures, and cattle in south Georgia, USA

Abstract

Native forages of the southern United States are frequently low in nutrients and poorly digestible, while improved pastures are the opposite. Since this area produces rapid growth of pines, which is a major use of the land, the integration of pines, pastures, and cattle seem to offer an efficient and economical form of management. Therefore, in a 20-year study Coastal bermuda (Cynodon dactylon), dallis (Paspalum dilatatum), and Pensacola bahia (P. notatum) grasses were grown in pastures with no trees, and with slash pine (Pinus elliottii) spaced 3.7 × 3.7 and 6.1 × 6.1 m. The trees were grown free of competition for 3 years, grasses were established during the 4th year, and grazing by yearling cattle began the 5th year. The pastures were then fertilized, grazed, and burned for 15 years. Increasing tree canopies reduced forage production of all grasses. Bahiagrass was the most shade tolerant, while Coastal bermuda was the least. Liveweight gains during the 15 years of grazing totaled 3933, 2302, and 1518kg/ha from pastures with no pines and slash pine spaced 6.1 × 6.1 and 3.7 × 3.7, respectively. Survival of slash pine was low due to heavy attacks by southern pine coneworm and southern fusfform rust. However, the trees grew rapidly and averaged 19.0 and 16.9 m in height, 30.0 and 33.3 cm in diameter, and 181.4 and 90.7 m3/ha of pulpwood after 20 years from the 3.7 × 3.7 and 6.1 X 6.1 spacings, respectively. Slash pine at these spacings planted in undisturbed, native vegetation were 16.0 and 15.7 m tall, 19.6 and 23.4 cm in diameter, and produced 145.5 and 63.6 m3/ha of pulpwood. Combining the production of pines and beef on improved pasture offers an opportunity for multipleproduct yields. Since this approach to agroforestry is not trouble-free, good management is required. Landowners, especially those with small holdings, should consider these alternatives to single-product management when planning their cropping system.

Integration of pines and pastures for hay and grazing

“…There were only small differences in gains as influenced by tree spacings because both spacings had the same density. These animal responses are similar to those at similar plantation ages from the earlier study of combining pines and pastures [13].…”

“…The proven shade tolerance of Pensacola bahiagrass over Coastal bermudagrass [6,13] could become very important when pine crowns provide more a None of the differnces were statistically significant at the 0.05 level Figure 3. Beef production from pastures planted with widely-spaced rows of pines was high since shading had a minimum influence on the grasses.…”

“…A second study allowed pines to grow for 3 years before planting the pasture grasses during the 4th year. Grazing began the 5th year when pines were large enough to prevent breakage or major browsing damage [13]. Postponing grazing for 3 to 4 years eliminates any opportunity for pasture or livestock returns during the early part of the tree rotation.…”

Tree canopy effect on grass and grass/legume mixtures in eastern Nebraska

“…The response with AVGLAI demonstrated that CP of SB leaves at LAI levels below 0.5 almost reached 80 g kg -1 , but CP remained above 250 g kg -1 when the overstory LAI was greater than 3.0. The response of leaf CP to light levels corresponds with other studies (Allard et al 1991;Kephart and Buxton 1993;Lewis et al 1983). Although shading appears to have a positive influence on tissue CP content, shading is commonly reported to lower soluble carbohydrate level in plants contributing to a decline in herbage dry matter digestibility (Wilson 1984;Buxton and Casler 1993).…”

Environmental quality improvement of agricultural lands through silvopasture in southeastern United States

“…Several studies conducted since then have produced results influencing the practice of silvopasture (Halls et al, 1957;Lewis et al, 1983;Lewis & Pearson, 1987;Pearson & Rollins, 1987;Clason, 1995;Zinkhan & Mercer, 1997), especially in the configuration of trees and the type of forage grass used by landowners. Recent work in silvopastoral systems suggests that compared with treeless pastures, silvopasture might have a greater potential to sequester carbon (C) (Haile et al, 2006), and also to remove excess nutrients (Nair et al, 2007) particularly from the deeper horizons of sandy soils which could result in environmental improvement of agricultural lands.…”