Chemistry Reference
In-Depth Information
AMF spore abundance or root colonisation. Trends, however, showed soils
under napier (Pennisetum purpureum Schumach) and tea (Camellia sinensis L.)
had the highest AMF spore abundance while natural forest and planted forest
had the least spore abundance (see Figure 4). The reverse was observed for
root colonisation where the highest colonisation was in soils under natural and
planted forest, except tea which maintained both high spore abundance and
slightly high colonisation.
Infection of crop roots with AM fungi can improve the uptake of nutrients,
particularly phosphorus, and increase crop production.
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These endomycor-
rhizal fungi are obligate symbiotic fungi, the hyphae of which develop mycelia,
arbuscules, and in most fungal genera vesicles in roots. Soil hyphal networks
produced by these symbiotic fungi provide a greater absorptive surface area
than plant root hairs. As such, mycorrhizal symbiosis assists crops in
recovering scarce reserves of soil phosphorus. In addition, mycorrhizal-
infected plants have been shown to have greater tolerance to toxic metals, root
pathogens, drought, high temperatures, saline soils, adverse soil pH and
transplant shock than non-mycorrhizal plants.
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Mycorrhizal association has
been recognised for cassava production, given that it is usually grown in
infertile soils, without fertiliser application.
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Inoculation of orange-fleshed
sweet potato varieties with mycorrhizal fungi and phosphate-solubilising
bacteria (PSB) in the low-phosphorus soils increased phosphorus concentra-
tion in the soil and root yield. Arbuscular mycorrhizal fungi therefore
constitute one of the strategic interventions for ISFM. Two basic strategies to
manage
d
n
1
r
2
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g
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4
mycorrhizal
fungi
are
available
through
optimising
crop
and
Figure 4
Impact of land use type (LUT) in order of less-to-high intensity on spore
abundance and colonisation. (Source: Jefwa et al.).
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