A Systematic Review

How the review was carried out is briefly described. The review looks mainly at the literature published since year 2000, but does not exclude earlier publications. The sustainability of practices to limit erosion must be assessed not only in terms of the soil resource and the wider environ-ment but must also take into account economical and socio-political factors. Soil degradation may be due to a number of causes and it may be that in places erosion is not the main factor. So how erosion is assessed and perceived may be an important factor if degradation is to be successfully tackled. Certainly, in many parts of the world farmers do not, or cannot, combat erosion. A brief history of soil conservation practices is given and then these techniques are examined in more detail in terms of their environmental, economical and socio-political sustainability. Many practices are environmentally sustainable, especially those used by small indigenous farmers, but few are sustainable in financial and socio-political terms. Although conservation tillage techniques are being vigorously promoted they may be more sustainable when carried out on small farms where no herbicide inputs are needed. It is the economical and socio-political factors that lead to erosion which need to be tackled if sustainable practices to limit soil erosion are to be successful