become the focus of this publication. In other countries international systems (FAO; World Reference Base-WRB or Soil Taxonomy) were adapted to local edaphic conditions.

Keywords

Hierarchy Soil classification World Reference Base Soil taxonomy Kuwait

1.1Introduction

National soil inventory is important in the current situation, where, in 2050 it is likely that agrifood sector will face a momentous challenge to produce high quality and nutritious food to feed 9 billion peoples (Charles et al. 2010), that is 3 billion more mouths to feed than there were in 2010, while dealing with the impact of climate change on natural resources. Soil classification deals with the systematic categorization of soils based on distinguishing characteristics as well as criteria that dictate choices in use. It separates soil into classes or groups each having similar characteristics and potentially similar behavior. There exists number of soil classification systems. According to Food and Agriculture Organization-FAO, Soil classification concerns the grouping of soils with a similar range of properties (chemical, physical, mineralogical and biological) into units that can be geo-referenced and mapped. In the soil survey of Kuwait, we used United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS) soil classifi- cation system, which has found widespread international acceptance particularly in countries in Latin America and Asia. The principles that were developed by Soil Taxonomy were taken up by World Reference Base (WRB) and the FAO Legend to set international standards.

1.2History of Soil Classification Systems

The earlier USDA soil classification (Baldwin et al. 1938) divided soils into three orders and was focused on the environment and the soil forming factors to classify soils in zonal, azonal and intrazonal soils. A later development focused on the processes occurring in the soil itself. These processes were roughly characterized by