Changes in Soil Physico-Chemical Properties in different Land Use Systems of Manipur, Northeast India

The current study examined the soil physico-chemical properties of five different land uses (e.g. Mixed pine forest, MPF; Pine plantation, PP; Lithocarpus forest, LF; Quercus forest, QF; and Dipterocarpus forest, DF) in Manipur, India. Replicated soil samples from three soil depths (i.e., 0-10 cm, 10-20 cm, and 20-30 cm) were collected from each land use type and analyzed for soil physical and chemical properties. Sand percentage was highest in DF and lowest in QF. The soil pH varied between 4.3 and 5.3 in different land uses. The highest water holding capacity (84.86%) was in PP and lowest (55.46%) in LF. The bulk density was highest in LF and QF (1.04 g/cm³) and lowest in DF (0.85 g/cm³). The highest soil organic carbon and organic matter were in PP (30.6 and 59.5 Mg/ha) and lowest in MPF (6.6 and 11.2 Mg/ha).The stocks of nitrogen, phosphorus and potassium in different systems ranged 250.5-438.7 kg/ha, 12.7-54.8 kg/haand 102-236.20 kg/ha, respectively. Higher accumulation of soil organic carbon and nutrients in PP within a short period of time (40 years) compared to others are because slow decomposition of pine needle.