The establishment and early growth of three leguminous tree species for use in silvopastoral systems of the southeastern USA

Abstract

Demand for goat meat in the eastern USA is growing as a result of preference by ethnic communities. Meat goat production systems in the southeastern USA should be designed to take advantage of the goats' natural preference for browse. Trees could contribute to system productivity by supplying required nutrients when demand by growing animals is critical and the quality of forage is limited. A field study was established in Wake County, NC to evaluate the establishment and early growth characteristics of three leguminous tree species, Robinia pseudoacacia, Gleditsia triacanthos, and Albizia julibrissin. The three tree species were planted in single-row plots following a randomized complete block design (3 × 2 × 2, replicated six times) with two planting densities (intra-row spacing of 50 or 100 cm) and two coppice heights (25 or 50 cm). Bare-root seedlings were planted in March 1995, evaluated for browse quality (composited samples) in August 1995, coppiced in February 1996, evaluated for herbage mass and quality in July 1996, and evaluated for goat preference in August 1996. Herbage mass produced during the second season ranged from about 200 (G. tricanthos) to 3,200 kg/ha (R. pseudoacacia). Estimates of herbage quality were high for all species. Crude protein and acid detergent fiber of leaflets ranged from 23 to 28% and 12 to 22%, respectively. Robinia pseudoacacia has a high potential as a browse species for goats due to high herbage production (mean of 2,390 kg/ha) and goat preference. Gleditsia triacanthos was judged to be a low value browse species. Albizia julibrissin, although not highly preferred by goats in the trial holds sufficient potential to warrant further investigation.