Quantitative criteria for distinguishing melanic from vertic soil horizons in the central Kruger National Park

摘要

Criteria based on shrink-swell potential,viz.linear shrinkage and COLErod, were used to distinguish between melanic and vertic soil horizons of the Mooiplaas region in central Kruger National Park. For linear shrinkage the proposed boundary value separating melanic and vertic horizons lies at 14, with ranges from 6 to 14 and 14 to 22, respectively. Because a significant relationship existed between linear shrinkage and COLErod, the latter could be regarded as a reliable guide for measuring the expansiveness of soils. In addition, this method is fast, requires no expensive laboratory equipment, can be done with relative ease in the field, and furnishes reproducible results. Melanic horizons had COLErod values of 7#x2013;13 and vertic horizons 13#x2013;20.