Source: UNEP (2010): The GEO Data Portal, as compiled from FAO, TERRASTAT I Global GIS Databases Poverty and Food Insecurity Mapping Project. United Nations Environment Programme.
It is possible to assess the suitability of a biophysical area to different forms of crop production, such as cereals, by looking at their potential yield under natural conditions and their average market price. For an area, the cereal with the highest value of the yield/value ratio is considered the best suited. The most suitable cereal usually corresponds to the practiced agricultural form, but these vary according to market changes. An increase in the price of a specific cereal is usually associated with an expansion of its areas under cultivation. There is substantial potential for expanding rice cultivation but at the expense of complex ecosystems such as the rain forest. Irrigation also enables agriculture in areas that are technically unsuitable.