The Changes of Physic and Chemical Characteristics on Vertisol that Application of Kinds of Organic Matter and Sands

Vertisol has a clay texture, high micropores, and high water and nutrient absorption ability. The high water content of vertisols causes the air to decrease, thus inhibiting root development. Stretching of the vertisol structure is expected to increase soil porosity, reduce ion and water absorption. This study and aims to examine the effectiveness of the combination of organic matter and percent sand on porosity and nutrient availability. The study was arranged according to a factorial Completely Randomized Design (CRD) which was repeated 3 times. The first factor is 7 types of organic matter (control, humic acid, biochar, humin, compost + manure, water hyacinth + manure. The second factor is the percentage of sand: 0%, 20%, and 40%. The application doses are respectively each treatment: humic acid and humin 20kg/ha, biochar 1 ton/ha, compost+manure fertilizer 15 tons/ha. Changes in soil chemical characteristics were evaluated against pH, C-org , P-available, while changes soil physich characteristics were evaluated against BI, BJ, and soil porosity. The results showed that the combination of organic matter and percent sand could improve the physical and chemical characteristics of the soil. BI, BJ and soil porosity increased with the addition of sand. The organic matter which was significantly correlated with positive improvement of soil properties was humic acid, humin, biochar, compost, and manure, with the best percentage of sand at 20%