EXPLORING LAND QUALITY EFFECTS ON WORLD FOOD-SUPPLY

In a previous study, simulations of agricultural production potentials were made for different exploratory scenarios considering population growth, type of diet and low and high input agriculture. Results indic ated that future world populations can be fed, but problems are likely in South Asia. The simulations involved gross generalizations for soi l conditions. For example, possible effects of soil degradation were n ot expressed. The current study was made to explore the effects of the different types of soil degradation on agricultural production, using major soil groupings of the Humid Tropics and Seasonally Dry (Sub)Tro pics as examples. Degradation (compaction, erosion and acidification) is expressed in terms of soil quality indicators relating potential to actual production. Results are characteristically different for diffe rent soil units (genoforms), and the suggestion is made to present suc h differences in future soil databases for phenoforms that express eff ects of different forms of degradation or improvement, allowing better assessments for exploratory land use scenarios. Field studies should be initiated to describe realistic phenoforms for any given genoform. (C) 1998 Elsevier Science B.V. All rights reserved.