KARAKTERISTIK BIOLOGI DAN KIMIA TANAH SAWAH AKIBAT PEMBAKARAN JERAMI Biological and Chemical Characteristics Burning Rice Straw of Paddy Soil

The aim of this research was to study the biological and chemical characteristics of paddy soil caused of burning rice straw. This research was conducted in Subdistrict Tanjung Morawa, District Deli Serdang, North Sumatera Province. Sampling was done at the public rice field with straw burning over it and Balai Benih Sari Murni which never burning straw. Soil samples were taken under the heap of burnt straw in three times, i.e after burning soon (0 week after harvesting), 1 and 2 week after harvesting to analyze the number of arthropod an microorganisms, soil colour, texture, pH, C-organic, N-total, P-available, and K-exchangable in The Soil Biology, Soil Chemical and Fertility, and Research and Technology Laboratory, Agricultural Faculty of North Sumatera University, Medan. The results showed that the soil with straw burning over it has the number of arthropod and microorganism, C-organic, N-total, and P-available is lower than the unburnt soil. pH and K-exchangeable of the burnt soil is higher than the unburnt soil. In 2 weeks after burning, the number of arthropod and microorganism, C-organic, and P-available gets recovery from before.