L. Nunezregueira et al., EFFECT OF STORAGE OF SOIL AT 4-DEGREES-C ON THE MICROBIAL ACTIVITY STUDIED BY MICROCALORIMETRY, Journal of thermal analysis, 41(6), 1994, pp. 1379-1383
The effect of the storage of soils on their microbial activity has bee
n studied using a microcalorimetric method. Soil samples were kept in
closed polyethene bags at 4-degrees-C during 3-6 months. Results show
changes in the slope of the different P-t curves recorded from the sam
ples stored at 4-degrees-C. This fact strongly suggest the existence o
f changes of the microbial activity of soil as the heat evolution is a
direct measurement of the cells metabolic activity. The value of the
Peak-time (time in which the microcalorimetric signal reaches the maxi
mum value) is related with the microbial density of soil samples. This
parameter was affected by the time of storage increasing with time. T
he total heat evolution Q(t), of the soil samples amended with glucose
calculated from the area limited by the Power-Time curves, also decre
ases with the time of storage. The soil that had been stored for 6 mon
ths before experiments, showed the lowest value of Q(t).