The Availability of Manganese in the Soil.

Abstract

Recent work on the solubility of manganese compounds in the soil, leading to a general consensus of opinion that the solubility of this element is intimately controlled by the soil reaction and by the oxidation-reduction equilibrium, is shown to have an important bearing on the availability of this element to plants. This has been established by means of laboratory tests and pot experiments on three different soil types, characteristically deficient in available manganese. It has been shown that normal plant growth can be established on such soils either by increasing the acidity of the soil or by subjecting the soil to reducing conditions such as those brought about by high water saturation or temporary waterlogging. On these soils the increases in growth amounted to several hundred per cent. These responses are in every respect similar to those obtained by the application of manganese sulphate to the soils.