ABSTRACT
An opinion is also emerging that plant growth and soil variability are related, and often constitute an outward manifestation of the physical nonequilibrium process. A perceived diversity in natural ecosystems frequently reflects local soil variability, Direct methods of measuring hydraulic conductivity, retention curve, and other hydraulic properties are well-established and documented in the literature. Needed values are easily measured in the field, or are readily available from a comprehensive soil survey database. The extent of soil profile maturity, position and definition of impeding layers, internal soil structure and color, as well as distribution with depth and forms of elements such as phosphorus, and to a lesser extent nitrogen, sulfur, and organic carbon, serve as indicators of water movement and equilibrium status of a soil pedon. The advent of Geographic Information Systems (GIS) has allowed rapid manipulation and display of large quantities of related spatial data.
