TY - JOUR
T1 - Huge increases in bacterivores on freshly killed barley roots
AU - Christensen, S.
AU - Griffiths, B.
AU - Ekelund, Flemming
AU - Rønn, Regin
N1 - Keywords:Barley root;Bacterivore;Microbial activity;Microfaunal activity
PY - 1992
Y1 - 1992
N2 - Adding fresh roots to intact soil cores resulted in marked increases in microbial and microfaunal activity at the resource islands. Microbial activity increased in two phases following root addition. Respiratory activity and concentration of respiratory enzyme (dehydrogenase) in soil adhering to the roots was very high during the first three weeks resulting in anaerobic conditions in the soil. After a period of low respiratory activity and enzyme content, these quantities increased from 6 to 20 weeks, but not enough to maintain anaerobic conditions. Numbers of protozoa peaked earlier than the nematodes. Based on yield coefficients of microbes and bacterivores, the increase in bacterivores was in accordance with root-induced respiration activity. In soil adhering to roots, numbers of bacterial grazers (protozoa and nematodes) were up to 80 and 30 times higher, respectively, than in the surrounding soil. This effect is up to 20 times higher than observed around live root systems, which may suggest that the rhizosphere effect on microbivores could for the major part result from the decomposition of dead segments of the root system.
AB - Adding fresh roots to intact soil cores resulted in marked increases in microbial and microfaunal activity at the resource islands. Microbial activity increased in two phases following root addition. Respiratory activity and concentration of respiratory enzyme (dehydrogenase) in soil adhering to the roots was very high during the first three weeks resulting in anaerobic conditions in the soil. After a period of low respiratory activity and enzyme content, these quantities increased from 6 to 20 weeks, but not enough to maintain anaerobic conditions. Numbers of protozoa peaked earlier than the nematodes. Based on yield coefficients of microbes and bacterivores, the increase in bacterivores was in accordance with root-induced respiration activity. In soil adhering to roots, numbers of bacterial grazers (protozoa and nematodes) were up to 80 and 30 times higher, respectively, than in the surrounding soil. This effect is up to 20 times higher than observed around live root systems, which may suggest that the rhizosphere effect on microbivores could for the major part result from the decomposition of dead segments of the root system.
U2 - 10.1111/j.1574-6968.1992.tb04822.x
DO - 10.1111/j.1574-6968.1992.tb04822.x
M3 - Journal article
SN - 0168-6496
VL - 86
SP - 303
EP - 310
JO - F E M S Microbiology Ecology
JF - F E M S Microbiology Ecology
IS - 4
ER -