TY - JOUR
T1 - Size and Persistence of the Microbial Biomass Formed during the Humification of Glucose Hemicellulose Cellulose, and Straw in Soils Containing Different Amounts of Clay
AU - Sørensen, Lasse Holst
PY - 1983
Y1 - 1983
N2 - 14C-labelled substrates were incubated at 20°C in 4 soils with clay contents ranging from 6 to 34%. Glucose was most readily decomposed, followed in order by hemicellulose, cellulose, maize straw, and barley straw. After the first 10 days of incubation, about 60% of the glucose-C had left the soils as CO2, compared with only 23% of the barley-C.The humified matter that remained in the soils after 3 months decayed at almost the same rate whether the origin of the matter was glucose, hemicellulose, cellulose or straw; this rate was, on the whole, independent of the caly content of the soils. Half-life values for the labelled C in the soils during the second and third year of incubation ranged from 5 to 7 years. The amino acid-C percentages of the humified matter tended in all four soils to be largest in matter originating from glucose and least in that originating from straw. The amino acid-C percentages increased with the clay content of the soils.The biomass was determined by fumigation with CHCl3 according to Jenkinson. After 3 months an average of 17% of the residual labelled C was in biomass; the values ranged from 37% when the labelled C was added as glucose to 2–9% when added as barley straw. The half-life of labelled C in biomass during the second year of incubation ranged from 2 to 3 years.Native C in biomass ranged from 0.5 to 1.4% of the total C in native soil organic matter, the highest values occurring in the clay-rich soils. The half-life of native soil C, estimated from CO2 evolution during 3-month periods, ranged from 13 to 29 years.
AB - 14C-labelled substrates were incubated at 20°C in 4 soils with clay contents ranging from 6 to 34%. Glucose was most readily decomposed, followed in order by hemicellulose, cellulose, maize straw, and barley straw. After the first 10 days of incubation, about 60% of the glucose-C had left the soils as CO2, compared with only 23% of the barley-C.The humified matter that remained in the soils after 3 months decayed at almost the same rate whether the origin of the matter was glucose, hemicellulose, cellulose or straw; this rate was, on the whole, independent of the caly content of the soils. Half-life values for the labelled C in the soils during the second and third year of incubation ranged from 5 to 7 years. The amino acid-C percentages of the humified matter tended in all four soils to be largest in matter originating from glucose and least in that originating from straw. The amino acid-C percentages increased with the clay content of the soils.The biomass was determined by fumigation with CHCl3 according to Jenkinson. After 3 months an average of 17% of the residual labelled C was in biomass; the values ranged from 37% when the labelled C was added as glucose to 2–9% when added as barley straw. The half-life of labelled C in biomass during the second year of incubation ranged from 2 to 3 years.Native C in biomass ranged from 0.5 to 1.4% of the total C in native soil organic matter, the highest values occurring in the clay-rich soils. The half-life of native soil C, estimated from CO2 evolution during 3-month periods, ranged from 13 to 29 years.
U2 - 10.1007/BF02178619
DO - 10.1007/BF02178619
M3 - Journal article
VL - 75
SP - 121
EP - 130
JO - Plant and Soil
JF - Plant and Soil
SN - 0032-079X
IS - 1
ER -