UTAH ACADEMY OF SCIENCES 245 
EFFECT OF GREEN MANURE AT DIFFERENT 
STAGES OF GROWTH UPON THE RELA- 
TIVE ABUNDANCE OF ACTINOMYCES, 
NON-SPORE-FORMERS AND SPORE- 
FORMERS IN THE SOIL. 
BY DR. THOMAS L. MARTIN. 
(Abstract). 
PURPOSE: 
According to some investigators there are three 
groups of organisms in the soil. Actinomyces, Non- 
Spore-Formers and Spore-Formers' constitute these 
groups. They exist in a certain numerical relationship 
to each other. Every external influence affects the rela- 
tive abundance of these organisms. It was desired in 
this work to determine what the effect would be on the 
relative abundance of these organisms when green 
manures at different stages of maturity were added to 
the soil. 
METHOD: 
Rye, oats and buckwheat were harvested at three 
different stages of growth. This material was cut into 
small pieces and incorporated at the rate of five tons of 
green manure to the acre in gallon pots filled with a clay 
loam soil. After decomposing for five months samples 
were taken, tap-water gelatin plates poured and counts 
made after ten days’ incubation. 
