The reaction between dilute acids and the phosphorus compounds of the soil

Few reactions are more important to the soil chemist than that involved in the action of dilute acids on the phosphorus compounds of the soil, but, owing to its complex nature, little has been definitely ascertained about it. The importance of the reaction lies in the fact that it affords a distinction between those phosphorus compounds which are fairly easily soluble, and may therefore be expected to enter the plant root without much difficulty, and the less soluble compounds which are of less value in the nutrition of plants.