Economic implications of silvipastures on southern pine plantations

摘要

In 1984, five silvipasture treatments of native grasses (NG), Au-Lo-Tan lespedeza (L), bahiagrass (B), common bermudagrass (CM), and Coastal bermudagrass (CB), were established in a thinned 20-year-old loblolly pine plantation. Pine growth data were collected in 1984, 1987, and 1989. From 1986 to 1988, annual forage production was evaluated at 21-day intervals from April to October with forage dry matter yield and quality determined for each sampling interval. Forage management improved timber production with 5-year lumber growth on the NG, B, CM, and CB treatments exceeding the untreated plantation by 5.4 m3ha−1. Forage protein content, IVDMD, and P levels did not differ among treatments but daily dry matter yield did (p=0.05). Mean 3-year daily dry matter yields were 7.4, 5.9, 12.3, 8.3, and 18.5 kg ha−1for NG, L, B, CM, and CB. Financial comparison of a CB open pasture with a CB silvipasture showed that the silvipasture internal rate of return exceeded the CB open pasture by 7.3. A loblolly pine-forage intercropping system is a suitable management option for maturing plantati