Soil Organic Carbon Stock Assessment in a Grassland and a Polyculture Tree Plantation

Abstract

Polyculture tree plantations are generally characterized by the sustainability to resist disturbance, potential for higher yield and better ecological services. A study was conducted in a polyculture tree plantation and a grassland site inside the main campus of Visayas State University, Baybay City, Leyte to (1) estimate and compare the soil organic carbon (SOC) stocks between the two land uses, and (2) find relationships between soil physicochemical properties, and SOC in the polyculture tree plantation and grassland. In each land use, soil samples were collected at depth intervals of 0-10 cm, 10-30 cm, and 30-50 cm. Higher SOC stocks in the 10 – 30 cm and 30 – 50 cm depths and the whole profile of the polyculture tree plantation (23.02, 43.28, 45.18, 111.47 Mg C ha-1 , respectively) compared to the grassland site (27.53, 35.70, 28.93, 82.14 Mg C ha-1 ) were observed. Thus, this polyculture tree plantation significantly improved some soil physicochemical characteristics and increased SOC stock after conversion from grassland.