Effect of Amelioran Material on Soil Chemical Properties of Incubated Peat Planting Media in Polybag

The aim of this study was to obtain the best combination of types and doses of ameliorant materials: dolomite, rock phosphate, and mineral soil to improve the chemical properties of soil which was incubated for one year in peat media in polybag. The research was conducted in May 2015 - April 2016 in the experimental garden in the village of Sijambi, Tanjungbalai, North Sumatra. Elevation 3 m above sea level, with the C2 (Oldeman) climate type. The experiment was compiled using a Randomized Block Design, with 3 treatments of ameliorant material. The three ameliorant materials were tested for 3 doses. The addition of dolomite treatment: A1=0.45 kg polybag-1; A2=0.90 kg polybag-1; A3=1.35 kg polybag-1. The addition of rock phosphate treatment: A4=0.45 kg polybag-1; A5=0.90 kg polybag-1; A6=1.35 kg of polybag-1. The addition of mineral soil treatment: A7=0.45 kg polybag-1; A8=0.90 kg polybag-1; and A9=1.35 kg polybag-1.The results shown that the highest dose of dolomite (1.35 kg polybag-1) improved soil chemical properties, including soil pH and alkali cations (K, Ca and Mg) on incubated peat soil. Addition of rock phosphate with the highest dose of 1.35 kg polybag-1 (A6) increases available phosphorus and soil CEC. Addition of mineral soil dose of 0.90 kg polybag-1 (A8) increases soil CEC. In the analysis of total soil nitrogen, the highest increase was obtained by adding dolomite dose of 0.45 kg.polibag-1 (A1).