Climate Change Mitigation - Climate Resilient Agriculture for Ensuring Food Security - page 278

• Management of mycorrhiza and other
promising benefi cial microorganisms
• Focusing efforts towards correcting
micronutrient defi ciencies
• Using nitrifi cation inhibitors to reduce
chemical use and promote INM
• Integration of agro-forestry with
cropland management to increase
sequestration of soil carbon and
reduce nutrient leakage
• Quality labeling and specifying
microorganism application for agri-
culture, horticulture, greenhouse
products, etc.

amounts of C sequestration in a maize-mycorrhizal
system. Arbuscular mycorrhizal fungi (AMF)
release glomalin which stores about 30-40 % car-
bon in the form of carbohydrates and proteins. It
is a superglue that helps store carbon, nutrients,
and benefi cial microorganisms, as well as being
involved in stabilizing soil aggregates. It also
offers protection against biotic and abiotic stress
conditions that could decrease crop growth
and therefore reduce carbon sequestration
(Subramanian et al. 2009 ).
Mycorrhizal inoculation resulted in coloniza-
tion of roots irrespective of fertility gradients and
crop growth stages (Subramanian et al. 2009 ).
The uninoculated treatments registered less than
5 % colonization shortly after planting, but the
percentage of colonization tended to increase
signifi cantly with the advancement of plant
growth. The glomalin content of the soil substan-
tially increased with mycorrhizal association,
suggesting that mycorrhiza plays a vital role in
conserving the carbon in a long-lived pool, which
prevents loss of carbon to the atmosphere while
sustaining soil fertility. Although soil glomalin
concentration was not affected by chemical
fertilizer levels, combined application of fertil-
izer and rice straw signifi cantly increased soil
glomalin concentration, which result into the
greater soil organic carbon conservation
(Subramanian et al. 2009 ).
Mycorrhizal plants are generally photosyn-
thetically more active and capable of converting
more atmospheric CO 2 into assimilates in the
plants (Subramanian et al. 2009 ). Mycorrhizal
symbiosis utilizes at least 10 % of the host plant's
photosynthetic carbon which helps the microbial
activity in the rhizosphere and contributes to the
enhancement of active carbon pool in the soil.
Shoot and root biomass of Glomus intraradices
mycorrhiza-inoculated maize plants were signifi -
cantly increased about 29 % in comparison with
uninoculated plants with there being more
enhancement when soil zinc levels were low
(Subramanian et al. 2009 ). Thus, AMF that form
symbiotic relationship with more than 90 % of
terrestrial plant species are helpful in storing car-
bon in living soil pools. However, the degree of
dependence on mycorrhizae varies with plant

13.1.2.2 Mycorrhiza
Mycorrhiza assists plants in obtaining soil nutri-
ents. Therefore, any resulting stimulations in
plant growth provide additional plant residue,
which in turn can lead to increased carbon storage
in the soil (Smith et al. 2008 ). However, mycor-
rhiza can also promote carbon sequestration
through a second mechanism. Mycorrhizae
release glomalin, which is a glycoprotein that
serves as gluing agent that facilitates soil aggre-
gate formation, improvement of soil physical
properties, and sequestration of carbon in the soil
(Rillig 2004 ; Subramanian et al. 2009 ). The sta-
bility of soil aggregates is highly correlated with
the length of mycorrhizal hypha in the soil
(Jastrow et al. 1998 ).
One of the prime factors associated with
enhancing soil carbon sequestration is the release
of glomalin in mycorrhizal systems. Specifi c
mycorrhizae, Glomus intraradices , G. mosseae ,
G. fascicullatum , G. margarita , and G. pellucida ,
have been reported to enhance soil carbon due to
the release of glomalin. Glomalin is a glycopro-
tein that serves as gluing agent that facilitates soil
aggregate formation and improves soil physical
properties (Rillig 2004 ). Glomalin secretion helps
to conserve soil carbon besides increasing micro-
bial biomass. Subramanian et al. ( 2009 ) reported
that glomalin is composed of 45 % carbon, like
most organic compounds, and it is considered to
be a major compound that is a store of carbon in
soil carbon sequestration. Since glomalin is a res-
ervoir of carbon, examining it helps explain