Kajian Tingkat Laju Limpasan Permukaan dan Erosi Berdasarkan Pengelolaan Tanaman Pertanian Sistem Agroforestry di DAS CiantenCipancar, Provinsi Jawa Barat, Indonesia
Increasing cultivation area in a watershed has implications on increase of runoff and erosion rate. Agroforestry system can reduce erosion rate through management of agricultural crops under the stand of annual plant of white teak (Gmelina arborea sp.). This study aims to assess the runoff and erosion rate in watershed area in some types of agroforestry cropping systems. In Cianten-Cipancar watershed area there are several crops cultivated i.e. maize, turmeric, red bean and local chili. In order to assess the runoff and erosion rate in watershed area is designed 3 experimental plots involving 4 types of horticultural crops. Plot 1 uses intercropping turmeric, maize, red bean, local chili. Plot 2 uses intercropping turmeric, corn, red beans. Plot 3 uses pattern of monoculture planting of local chili. The average rainfall of 21.6 mm is resulted in runoff 0.28 mm (Plot 1), 0.55 mm (Plot 2) and 0.94 mm (Plot 3). Intensity of rainfall on each plot (63.4 mm/h, 51.6 mm/h, 63.4 mm/h) resulted in runoff and erosion 0.83 mm, 29.67 kg/ha, 1.59 mm, 275.01 kg/ha, 5.0 mm, 464.78 kg/ha, respectively. Average erosion occurring was 9.27 kg/ha (Plot 1), 55.65 kg/ha (Plot 2) and 101.23 kg/ha (Plot 3). The rain events in the study was 30 times with a total rainfall of 647.11 mm. The smallest rainfall of 0.2 mm resulted in runoff on Plot 3 of 0.01 mm and erosion of 1.13 kg/ha but in Plot 1 and Plot 2 there was no runoff and erosion.