A technique for the study of oxygen availability to micro-organisms in soil and its possible use as an index of soil aeration

Abstract

1. In Part I of the paper details are presented of a new technique for the study of oxygen availability to bacteria added to soil. In essentials the technique consists of adding a washed suspension of bacterial cells together with excess of suitable oxidizable substrate to air dried, sieved soil contained in Warburg vessels. The rate of oxygen uptake is looked upon as a function of the aeration conditions within the soil. The results can be expressed by means of a conventional figure called the aeration factor (or A.F.).2. In Part II with the use of the technique it has been shown that two physical properties of soil which influence oxygen availability under the experimental conditions of the technique are (a) moisture content of the soil, (b) the amount of break-up of the soil crumbs. Since the A.F. measures the resultant effect produced by these factors it may be regarded as an index of soil aeration.