Trends in Land Evaluation Assessment: A Review

Abstract

Assessment of relative ability of land for sustainable use is as old as farming practices although many of the
earlier methods used by farmers may not be scientifically justifiable. Different methods of assessing potentials
of land exist, including land capability/suitability evaluation and the current soil security concept and they
have their similarities and differences as well as merits and demerits. Assessment of natural (inherent) capacity
of land for sustainable use is land evaluation while soil quality is the assessment of dynamic capacity of land.
Soil quality assessment became popular and was used as advisory tools for farmers in the USA because it
encompasses three major issues of concern with respect to soil function (productivity, environmental quality,
and human/animal health). Soil quality assessment and land capability classification are broad in approaches
and thus one can be used in place of the other. This is not the case with land suitability evaluation which is crop
specific and uses variables that are slow to change and valid for a long-time period. However, soil quality
assessment can complement suitability evaluation since it can be more easily carried out on a periodic basis.
The most recent concept that brings biophysical and socio-economic perspective together in soil assessment is
soil security. Soil security is concerned with maintaining and improving the world's soil resource to produce
food, fibre and freshwater, maintain biodiversity and ecosystem services and contribute to human health.
There are five dimensions to soil security framework and they are capability, condition, capital, connectivity
and codification. However, a lot of work is still needed to bring this concept into fully developed risk-based
soil security assessment and policy framework.