Qs. Zhang, EFFECTS OF SOIL EXTRACTS FROM REPEATED PLANTATION WOODLAND OF CHINESE-FIR ON MICROBIAL ACTIVITIES AND SOIL-NITROGEN MINERALIZATION DYNAMICS, Plant and soil, 191(2), 1997, pp. 205-212
Effects of soil extracts from repeated plantation woodlands of Chinese
-fir on soil fungi growth, the activities of microbial communities, an
d rates of net soil nitrogen mineralization were investigated. Soil ex
tracts from replanted woodlands significantly inhibited soil non-patho
genic fungi growth, reduced soil respiration activities, and net soil
nitrogen mineralization rates. However, soil extracts from replanted w
oodland increased the growth of pathogenic fungi. The combination of s
oil extracts and pathogenic fungi did not significantly reduce the gro
wth of Chinese-fir seedlings when compared to the soil extracts alone.
The combination of soil extracts with pathogenic and nonpathogenic fu
ngi significantly increased the growth of Chinese-fir seedlings when c
ompared to the combination of soil extracts and pathogenic fungi. The
results suggest that the allelochemicals from soil extracts, rather th
an pathogenic fungi, are the key factor regulating the productivity an
d nitrogen cycling in repeated plantation woodlands.