Effects of Devegetation on Agricultural Soil Quality at Nnewi North Local Government Area of South Eastern Nigeria

ABSTRACT

This study evaluated the Impact of Devegetation on Soil environment of Nnewi North LGA in South East- Nigeria. It is caused by increasing demand for land with its consequences on disruption of soil ecology, climate change, breakdown of nutrient cycle and increase in soil erosion, siltation of dams and reservoirs, destruction of wildlife habitats, and loss of plant and genetic diversity. Soil samples for analysis were obtained in the study area from depth 0-15 cm, 15- 30 cm and 30-45 cm respectively. Conventional analytical methods were employed for the determination of selected physicochemical parameters: pH, NPK, organic

2+ 2+ + 3+ 2+ carbon,% sand, silt and clay; charged ions such as Ca , Mg , Na , Al , Fe ,

3+, 2+
and Zn . Heavy metals in the soil samples were analyzed using Atomic

Mn
Absorption Spectrophotometer (AAS). The pH values in all the sites had a mean concentration of 4.69, indicating acidity of the soil. Organic carbon concentration ranged between 0.45-0.60%, indicating low microbiological activities in the soil and hence increase in the concentration of carbon dioxide in the atmosphere. Mineral nitrogen had (0.06033 Mgkg-1) phosphorus (5.10–7.80 Mgkg-1) and potassium (0.05767 Mgkg-1) respectively. The soil may require some amendment to boost crop production. In general, there was heavy concentration of the mean values of sand (75.67 %), silt (5.300 %) and clay (19.0233 %) as well as low calcium and magnesium ion concentration in the soil, contributing to low fertility status at the area. The study recommended afforestation and integrated agriculture as a tool for sustaining the environment.

Keywords: Devegetation, Soil quality, Nnewi North L.G.A., Deforestation, Edaphic variables