Back C. Bourguignon
Laboratory for Analysis of Soil Microbiology, Marey-sur-Tille, France
Full Paper (PDF File: 168KB)
Abstract
Applied soil microbiology in agriculture deals extensively with studies
on the isolation, culture and use of Rhizobium spp. and mycorrhizae to
improve soil fertility, plant growth and yield. A significant amount of
the published literature on soil microbiology is devoted to these two groups
of beneficial microorganisms. Soil biology has had a relatively small impact
on agricultural practices in countries of the temperate regions where intensive
farming is well-developed, and where soil biological activity is generally
low. By contrast, the high biological activity of soils in tropical countries
is the main factor which limits crop yields. Our studies on agricultural
soils worldwide have shown that soil biological activity (as estimated
by phosphatase activity) is dependent on climatic factors and geologic
parent materials. In the tropics, soil biological activity is greatest
in the root surface-rhizosphere region of plants and with various faunal
associations. Our field work in Brazil has shown that soil biological applications
were responsible for a two-fold increase in the yield of rice and soybeans.