RECONNAISSANCE FOR SOIL SURVEY. II. PRE-SURVEY ESTIMATES OF THE INTRICACY OF THE SOIL PATTERN

The best procedure for mapping the soils of an area, and the effort this will require, depend upon the intricacy of its soil pattern. This paper presents one way of describing such intricacy-by a graph of variance against area sampled-and an exploratory attempt to determine its form for OM, N, coarse and fine sand, silt, clay, gravel, available P and K, CEC, exch. Ca, Mg and K, in areas in the Northern Territory of Australia. This confirmed that there are considerable differences between the graphs for different properties and that areas differ very much in the short- and long-range contributions to the total variability of their soil. It demonstrated the inevitable sampling problems in determining the form of variance-area graphs.