Soil carbon organic and cation exchange capacity (CEC) on rubber agroforestry land and rubber Monoculture land, Simalungun Regency, North Sumatra, Indonesia.

Soil fertility is the ability of the soil to provide nutrients needed by plants to support their growth and reproduction. The aimed of this research was to analyze of soil acid (pH), carbon organic, and cation exchange capacity (CEC) on rubber agroforestry and rubber monoculture land in Simalungun Regency, North Sumatra, Indonesia. Soil sampling is done by making 10 points of soil sample holes in a composite manner. Soil samples were taken with a depth of 0 – 10 cm and 10 – 20 cm. Differences of soil fertility between rubber agroforestry and rubber monoculture was analyzed using the independent T-test. The characteristics above indicate that there are differences in land use systems in the rubber agroforestry land is mixed with seasonal crops such as cocoa, while in the rubber monoculture land system, only one main type of crop is planted. The level of the content of pH, C-organic, and cation exchange capacity (CEC) found in monoculture land and rubber agroforestry has the same criteria, namely low. This research shows that there is no significant difference in each soil chemical parameters. [ABSTRACT FROM AUTHOR]