Land-use intensification and environmental degradation: empirical evidence from irrigated and rain-fed farms in south eastern Nigeria

When evaluating the potential of irrigation for agricultural production one must consider more than the technical and financial potential and feasibility of the scheme. Issues of environmental and social sustainability must also be considered. The purpose of the paper is to develop a framework for assessing the sustainability of an irrigation scheme and apply it in the context of one such scheme in south eastern Nigeria. The framework for assessment is based on a comparison of differential changes in environmental quality with and without the scheme, and before and after the scheme. thor does this by using measured soil characteristics for irrigated and adjacent rain-fed plots of agricultural land; and socio-economic analysis of other environmental and social impacts of the irrigation scheme. Data were collected through a field survey of the selected irrigated and rain-fed farm plots, qualitative interviews with the farm owners and relevant secondary sources. alyses find that the soils of the irrigated farms have been significantly degraded more than those of the rain-fed farms to the extent that precludes sustainable practice of arable agriculture on irrigated land in the study area. About 9% of the soils of the irrigated land have been degraded to the extent that they are no longer suitable for arable agriculture. Analyses of the qualitative interviews also find other bio-physical, social and economic impacts that significantly constrain long-term sustainability of arable agriculture in the study area.