PREPARATION OF HUMATE IRON AND OTHER HUMATE METALS

Abstract

Introduction It has been shown that humate iron is a highly active stimulator of bacterial growth and an excellent source of iron for the general nutrition of plants, and that it isoften more convenient to employ than other forms of iron now available, such as the sulphate, citrate, or tartrate (1, 2, 3, 6). It is, moreover, not precipitated in physiologically alkaline solutions nor by high concentrations of phosphate. Our previous studies in this connection were not concerned with efficient methods of preparation of humate iron, since most of the work involved microcultures of bacteria and hence relatively small requirements of material. In view of the considerable interest in this form of iron, and other humate metals, which appears to have developed among plant physiologists, the conditions essential to obtaining the