A Review of the menace of soil erosion in Nigeria with specific reference to Southeastern States[Un examen de la menace d'érosion des sols au Nigeria avec une référence spécifique aux États du Sud-Est]

Erosion is recognized as one of the world's most serious environmental problems. In Nigeria, most especially the southeastern part, agricultural productivity, sustainability, and management for food security/sustenance have been undermined by the menace posed by soil erosion. This in itself entails the danger of soil exhaustion, of which accelerated erosion is often only a symptom in Nigeria. Soil erosion by, definition, is a systematic removal of soil, including plant nutrients, from the land surface by the various agents of denudation which occurs in several parts of Nigeria under different geological, climatic, and soil conditions. The degree of occurrence varies considerably from one part of the country to the other. Equally varied are the factors responsible for the inception and development of erosion, as well as the types that exist in several parts of the country. Through a productive review of existing research and field observations, this paper presents a comprehensive review of soil erosion in Nigeria regarding the Southeastern region as well as control measures aimed at reducing and mitigating the threats posed by soil erosion within the region. From these studies, the major causes of soil erosion across Nigeria are mainly human activities, climatic factors (rainfall), inherent geology, undulating topography, and soil nature while control measures such as provision of vegetative cover, proper soil and water conservation practices, use of adequate crop management techniques, community-based campaigns and enactment of laws with strict penalties against any activities that favour soil erosion have been widely suggested. Also, the Federal Government of Nigeria in collaboration with the World Bank have intervened by the establishment of the program NEWMAP (Nigeria Erosion and Watershed Management Project) whose primary objective is to reduce vulnerability to soil erosion in targeted sub-watersheds with a portfolio of US $508 million-plus additional financing of $400 million.