Soil Degradation under Sugarcane Cultivation in Northern Kwazulu-natal

In many crop producing areas of the world there are reports of yield decline and loss of productive potential in soils. Little is known about the long term effects of sugarcane monocropping on changes in physical, chemical and biological properties of soils. The aim of this study was to quantify the physical and chemical condition of soils under sugarcane production in northern Kwazulu-Natal, as industrial sugarcane yields have failed to break through the 'productivity plateau' during the past 15 years. Soil samples from 29 virgin and adjoining cultivated fields were examined with 15 originating from dryland and 14 from irrigated areas. The most prominent soil chemical properties contributing to soil degradation under sugarcane cultivation were increased acidity in dryland areas and increased salinity and sodicity levels in irrigated areas. The common thread linking results from the dryland and irrigated areas was the reduced organic matter of the cultivated relative to the virgin sites.