AbstractsChemistry

By the year 1855 agriculturalists had accumulated sufficient evidence to uphold the contention that phosphorus was essential in order to support plant growth. Numerous attempts have been made since that time to fractionate the categories of phosphorus in soil, and the problem is a very important and live issue to-day. [...] The purpose of this investigation was to develop a method of fractionation which could be applied to soils and soil extracts, and which would establish the nature of some of the organic and inorganic phosphorus components present in soil. [...] It has been known for many years that the total phosphorus content of soils cannot be used as a true measure of the capacity of different soils to supply available phosphorus to plant roots. On the other hand so called availability methods do give a good indication of the fertility status of soils. This has been explained by the fact that the buffered acid extracting solutions presumably dissolve a definite group of phosphorus compounds. It is also well known that acid extracting solutions dissolve widely different amounts of phosphorus from different types of soils. There is thus good evidence that the soil phosphorus does not exist in a uniform condition. The fractionation of the various forms in which phosphorus does exist in soils, is therefore a problem of vital interest. [...]