COMPARISONS OF FOUR METHODS FOR DETERMINATION OF DEGREE OF PEAT HUMIFICATION (DECOMPOSITION) WITH EMPHASIS ON THE VON POST METHOD

The degree of decomposition (humification) of 10 peats, ranging from undecomposed to completely decomposed, was determined by the following methods: (1) von Post’s method using 10 classes of humification, (2) pyrophosphate-soluble organic matter determination using an index derived from Munsell color charts, (3) unrubbed fiber content in percent of total, (4) rubbed fiber content in percent of total. All four methods provided reliable and useful information. The von Post method requires no instrumentation and is therefore most suitable for field use. It is the least time-consuming and the cheapest of the four methods. The pyrophosphate method is best suited to use in a laboratory. It does not always readily differentiate grades of well humified and completely humified peats. Both methods of determining fiber content require instrumentation and a steady, running stream of water. The rubbed fiber content more accurately characterizes the amounts of undecomposed fiber in peat. In the range of humic peats the two latter methods tend to differentiate fewer classes than does the von Post method. For the convenience of the reader the four methods are described in detail in the Appendix.