A. Hodge, Arbuscular mycorrhizal fungi influence decomposition of, but not plant nutrient capture from, glycine patches in soil, NEW PHYTOL, 151(3), 2001, pp. 725-734
The contribution of different arbuscular mycorrhizal fungi (AMF) to nutrien
t capture from an organic patch, and the subsequent impact on root prolifer
ation was investigated.
Organic patches were created with glycine labelled with N-15 and C-13. This
allowed decomposition (as (CO2)-C-13 release) and uptake of nutrients (as
C-13 and N-15 enrichments in the plant tissues) to be followed. Changes in
root responses were followed in situ by the use of minirhizotrons and compa
red to responses in control (H2O) patches.
Although there were differences in internal colonization and external mycel
ium production among the three AMF tested,. none of the fungi responded to
the presence of the glycine patch, and N and C capture was no different to
uncolonized controls. However, the presence of glycine affected the manner
in which colonized roots responded, particularly below the patch. The prese
nce of AMF affected the decomposition of glycine.
Root responses to the presence of N-rich patches appear more important than
AMF responses.