Inventarisasi dan Evaluasi Sifat Kimia Tanah pada Sistem Agroforestri di Kecamatan Silaen Kabupaten Toba

Abstract

Forest land conversion is one of the important problems faced today. The diverse composition of agroforestry systems makes agroforestry have a function and role closer to forests compared to agriculture. Currently, the implementation of the agroforestry system is still not widely used by farmers, especially in Silaen District, Toba Regency. The purpose of this study is to identify the distribution of agroforestry types in Silaen District, Toba Regency, as well as to find out the best and potential agroforestry types based on soil chemical characteristics. The research uses a survey method with a purposive sampling technique. Soil samples were taken at 11 coordinate points with a depth of 0-60 cm next, soil samples were analyzed in the Laboratory. The analysis of soil samples was carried out namely soil pH, C-organic, N-total, C/N ratio, P-available, K-exchange and Cationic Exchange Capacity (CEC). then the results of the study are described based on the Bogor Land Research Institute, 2005 on each parameter. Based on the results of the research, there are 3 types of agroforestry found in Silaen District, Toba Regency, namely: Agrisilvikultur, Agrosilvopastura and Agrosilvofishery. Si9A9 samples with agrisilviculture type were the best type based on the results of soil chemical analysis with pH values of 6.25 (slightly acidic), C-organic of 2.17% (moderate), total N-of 0.15% (low), C/N ratio of 14.50 (moderate), Pavailable of 43.59 ppm (very high), K-exchange of 238.20 mg/100g (very high), and KTK of 24.14 me/100g (moderate). The criteria for soil chemistry of agroforestry systems are slightly better than monoculture agriculture, but they are still below the criteria for forest soil chemistry.