ABSTRACT

Cracking clay soils (Vertisols and their intergrades) [Soil Survey Staff 2006] are important natural resources in a wide range of climatic zones, from humid tropical to arid dry areas of the world [Ahmad 1996]. The natural vegetation of these areas is dry deciduous forest. However, most of the soils are now under cultivation. Soils of these climates have a signi…cant role in the agricultural resource inventory of countries such as Australia, India, the Caribbean Islands, and the United States [Ahmad 1996].