Microbiological changes in freshly moistened soil

Abstract

IT is well known that when a dried soil is moistened there is a burst of respiratory activity. Drying, in some way, renders a part of the soil organic matter soluble and it has been considered that the decomposition of this fraction by micro-organisms partly accounts for the high respiration-rates recorded. The composition of this soluble material has not been fully determined, but it has been shown to contain appreciable amounts of several amino-acids1. In these circumstances the development of a specialized zymogenous population might be expected. Indirect evidence for the existence of such a population has been provided by Chase and Gray2. They made a detailed analysis of the respiration of freshly moistened soils and concluded that their results could be best interpreted by assuming that two major microbial populations were involved, namely, one with a low rate of metabolism - the autochthonous population - and the other with a very high rate - the zymogenous population. © 1961 Nature Publishing Group.