Agriculture Reference
In-Depth Information
On a given plant, bacterial populations generally respond more rapidly than fungi to root
products and have higher R/S ratios. Bacteria with
r
demographic strategies develop ini-
tially, followed by
K
selected bacteria; the latter have the capacity to digest the most
recalcitrant organic compounds, including cellulose and lignin (de Leij
et al.,
1994).
Maximum populations generally occur in the rhizoplane although, beyond a distance of
3 mm, population densities are little different from those of the extra-rhizosphere soil.
Nonetheless, individual populations of micro-organisms may have different distributions,
depending on their ecological requirements (Bazin
et al.,
1990) (Figure IV.34).
Microbial communities of the rhizosphere also differ qualitatively from the non-
rhizosphere soil. They appear to possess higher proportions of bacteria and free living
