Fuzzy logic based global assessment of the marginality of agricultural land use

In order to assess the agricultural potential of regions and to evaluate the risk of environmental degradation due to agriculture, we define a marginality index for agricultural land use which is based on available global data sets and takes into account various environmental conditions. Influencing factors taken into consideration are the general climatic conditions for plant growth, the soil fertility, the soil moisture availability, the precipitation uncertainty and the erosion risk due to the steepness of slopes. Comparison of our marginality index with present global assessments of agricultural land use shows that about 30% of agricultural land currently in use can be identified as marginal, in other words as having a disposition towards overuse and potential environmental degradation. The validity of our approach is strengthened by the fact that agriculturally used areas identified as marginal are described as vulnerable in the literature. The risk of degradation with a further intensification of agriculture on existing crop land and the potential for the cultivation of previously unused land can be identified using our fuzzy logic technique.