Determination of Factors Injurious to Plants in Acid Soils

Abstract

CROP failures on acid soils are well known to farmers and to scientific workers interested in plant nutrition, and to both the remedy of liming is equally familiar. There exists, however, little knowledge concerning the relative importance of the various factors which produce the injurious effects observed on acid soils, and the subject is in need of intensive study. The evidence regarding the possible factors concerned are discussed by Russell¹, and it will suffice here to mention the main probable causes of injury: (1) direct injury of hydrogen ions; (2) lack of available calcium; (3) lack of available phosphorus; (4) excess of soluble aluminium; (5) excess of soluble manganese; (6) biotic factors (for example, mycorrhiza).