
Arbuscular mycorrhizal fungi and organic farming
P. Gosling1, A. Hodge2, G. Goodlass3 and G.D. Bending1
Abstract
Symbiotic associations between arbuscular mycorrhizal fungi and plant
roots are widespread in the natural environment and can provide a range
of benefits to the host plant. These include improved nutrition, enhanced
resistance to soil-borne pests and disease, improved resistance to
drought, tolerance of heavy metals and better soil structure.
Many
agricultural crops are mycorrhizal and there is widespread if equivocal
evidence that crop plants benefit from the arbuscular mycorrhizal (AM)
association in the same way. However, many agricultural practices including
use of fertilisers and biocides, tillage, monocultures and the growing
of non-mycorrhizal crops are detrimental to arbuscular mycorrhizal
fungi (AMF). As a result, agroecosystems are impoverished in AMF and
may not provide the full range of benefits to the crop.
Organic farming
systems may be less detrimental to AMF because they exclude the use
of water-soluble fertilisers and most biocides and generally have diverse
rotations. The evidence available suggests that this leads to increased
AMF inoculum in soils, greater crop colonisation and enhanced nutrient
uptake. AMF might therefore be able to substitute for reduced fertiliser
and biocide inputs in organic systems, though there is little evidence
for increased yield resulting from high rates of AMF colonisation in
organic systems.
This review examines the benefits that the AM association
can have for agroecosystems and how farm management practices influence
the AM association. Management options that may be employed to increase
the benefits that AMF can bring to this type of farming system, such
as changes to the rotation and careful use of tillage, are discussed.
Source
Agriculture Ecosystems and Environment (2006) 113:17-35
Author Locations & Affiliations
(1) Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35
9EF, UK
(2) Department of Biology, Area 2, PO Box 373, University of York,
York YO10 5YW, UK
(3) ADAS High Mowthorpe, Duggleby, Malton, North Yorkshire
YO17 8BP, UK
en français
Posted March 2010