Pertumbuhan Karet (Hevea brasiliensis) dalam Sistem Monokultur dan Campuran dengan Akasia (Acacia mangium). Studi Kasus di Sembawa, Sumatra Selatan : II. Simulasi dengan Menggunakan Model WaNulCAS

Interplanting of Acacia mangium within rubber (Hevea brasiliensis) may be an attractive option for smallholder rubber farmers in the tropics to increase their land productivity. Light competition with rubber trees may occur as A. mangium being a very fast growing tree species. Thus, careful planting schedule of A. mangium is probably required to reduce light competition with rubber trees. This study presented results of exploration of growth of H. brasiliensis using WaNuLCAS model with scenario (1) A. mangium was planted few years (1 6 years) after H. brasiliensis planting and (2) A. mangium was slashed at 27 cm tree diameter. Result of WaNuLCAS model simulation showed that management option to delay the planting of A.mangium in respect to the planting of H. brasiliensis showed significant effect on the growth of H. brasiliensis. If the planting of A.mangium was delayed up to five years, year of tapping of H. brasiliensis almost similar to the monoculture systems. Planting A. mangium in the same year with H. brasiliensis or delaying the planting less than 5 years impacts both rubber and A. mangium growth. The longer the delay of planting of A.mangium, the faster H. brasiliensis reached tappable period but the longer it takes for A. mangium to reach harvestable size.