Warren G. Monson

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

Native forages of 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 x 3.7 and 6.1 x 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 1518 kg/ha from pastures with no pines and slash pine spaced 6.1 x 6.1 and 3.7 x 3.7, respectively. Survival of slash pine was low due to heavy attacks by southern pine coneworm and southern fusiform 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 x 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 multiple-product 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

When combining pine and cattle production on improved pastures, grazing may have to be delayed for several years until trees are large enough to resist injury. During this period forage would be lost unless harvested for hay. This study in south Georgia, USA, examined hay production during the first 3 years, cattle production during the next 3 years, and effects of this management system on survival and growth of slash pine(Pinus elliottii) planted in widely-spaced rows within the pastures.Pines were planted at 225 trees/ha in configurations of 3.0 x 14.6 or 4.9 x 9.1 m in pastures recently sprigged or seeded with Coastal bermudagrass (Cynodon dactylon) or Pensacola bahiagrass(Paspalum notatum). Pastures were fertilized annually and cut for hay four or five times each year.Wide-row spacings permitted haying operations, but tree rows and turning areas removed 5 to 8 percent of the area from production. However, hay yields and liveweight gains by yearling cattle were near normal for this locale.Slash pine planted in these fertilized pastures survived well, grew rapidly, and only a few trees were killed during haying operations. After 6 years, 83 percent of the trees survived and averaged 6.5 m in height and 13.2 cm in diameter. Cattle killed a few trees by rubbing during the 4th year.Wide-row spacing of pines permits harvesting forage for hay while waiting for the trees to become large enough to permit grazing. This approach to agroforestry produces annual returns to the landowner while awaiting maturity of the pines.

Isolation of Cuticle and Vascular Bundles of Leaves by Maceration in Rumen Fluid

We report a new macerating technique for plant leaves which permits the isolation of cuticle and vascular bundles. The maceration medium is rumen fluid, a complex mixture of interacting microorganisms, used full strength or diluted with a nutrient buffer solution in the ratio of 2:5. An incubation period of up to 72 hours at 39 C permits cuticle and vascular-bundle networks to be isolated. The technique is illustrated with fresh leaf samples from pearl millet, Pennisetum typhoides; orchardgrass, Dactylis glomerata; and alfalfa, Medicago sativa.