ABSTRACT
The land surface of the earth is highly variable. The highly variable properties of different surface features are considered as spatial variation. This variation exists from global to field scale, and within the field variations exist in soil physical, chemical, and biological properties at the level of the microenvironment (Foster 1988; Mzuku et al. 2005; Papiernik et al. 2005; Ensign et al. 2006). Humankind has been engaged in understanding and managing these spatial variations throughout history. The degree of understanding has depended on the socioeconomic needs and the technological advancement of any given time. Today, aerial photographs and satellite remote sensing have helped to understand these spatial variations in land use/cover more decisively than before at a regional to global scale (Moran et al. 1997). Simultaneously, scientific advances have also established the relationship between the distribution of natural resources and the food production system, which has paved the way for efficient resource management (Navalgund et al. 1991). Soil and water are the most important spatially varying natural elements and are critical to agricultural production, but the degree of variations is highly influenced by the scale at which these properties are described. Such variations can manifest in different soil types with features of waterlogging or inundation, dryness, erosion, and heterogeneity of soil physical, chemical, and biological properties. Thus, soils differ in their productive capacity to support human and animal life because of these variations.
