Influence of Land Use on Soil Physiochemical Properties in Semi-Humid Nsukka Area of Southeastern Nigeria

Abstract

The influence of four land uses (cultivated arable land, grassland, oil palm plantation and rubber plantation) on physical and chemical properties of coarsetextured acid soils was assessed in the semi-humid Nsukka area. Soil auger and core samples were used to achieve surface sampling at the depth intervals of 0-20 and 20-40cm in each land use type. Four diagnostic horizons were identified and sampled in each profile pit dug in each land use, which gave six samples per land use. Results showed that sand (90%) and silt (12%) fraction mean werehighest in oil palm plantation and rubber plantation respectively. The highest clay mean values were obtained from the surface samples (13%) of grassland land and the profile (24%) of rubber plantation. The oil palm plantation silt/clay (0.50) was less than unity and recorded the highest bulk density mean value (1.55 g/cm3 ). The highest value of saturated hydraulic conductivity (113.4 cm/hr) and available water capacity (53%) was recorded in the rubber plantation. The pH of the cultivated (5.7-6.8) and rubber plantation (6.2-6.3) soil increased with depth in contrast to grassland and oil palm plantation. The soil organic carbon and total nitrogen generally decreased with depth across the four land uses. The highest cation exchange capacity mean value was obtained from the surface samples of grassland (19 cmol/kg) and the profile of rubber plantation (16 cmol/kg). This shows that assessment of soil properties under different agronomic land uses will guide decisions on soil degradation associated with land uses