Changes in some Physico-Chemical characteristics of soils under poplar based agroforestry

Physical and chemical properties of soil in poplar (Populus deltoides Bartr.) plantations were evaluated in the alluvial soils of Punjab. The results showed that there was an overall improvement in the soil physical and chemical characteristics under poplar plantations. The magnitude of effects improved with increase in the number of cutting cycles of poplar. A decrease in soil pH and an increase in electrical conductivity (EC) were observed under higher age plantations. In the surface soil layer, the pH values ranged from 8.25 to 8.45 under different treatments. No significant effect of cutting cycles of poplar was observed on soil bulk density and particle density. Significant improvement in water holding capacity and cation exchange capacity with increase in cutting cycles of poplar plantations was observed upto 30 cm of depth. A general reduction in soil physical and chemical parameters with increase in soil depth was observed under different cutting cycles. The soil pH was lower whereas EC, bulk density, water holding capacity and cation exchange capacity were higher under paddy-wheat sequence than the poplar plantations.