Agriculture Reference
In-Depth Information
mineralization of organic P as a consequence of enhanced solubility of organic P
and hence its insusceptibility to mineral. The rate of organic P mineralization has,
however, been found to be greatly influenced by the activity of microorganisms in
the soil. Species of
Penicillium
(Gawas-Sakhalkar et al.
2012
),
Aspergillus
(Qureshi
et al.
2013
),
Rhizopus
(Acikel and Er¸an
2010
),
Mucor
(Boyce and Walsh
2007
),
Bacillus
(Mahesh et al.
2010
), and
Pseudomonas
(Cho et al.
2005
; Infantes
et al.
2012
) produce phosphatase that degrades nucleic acids, glycerophosphates,
and phytin. Since carbohydrate is required as C and energy source for mineral-
ization of organic P by soil microorganisms, the organic P mineralization in soil/
rhizospheres occurs very rapidly.
3.3 Conclusion
Optimal microenvironmental parameters and metabolizable C compounds must be
applied as energy source to the microbial solubilizers to ensure their growth,
organic acid production, and, simultaneously, P solubilization. However, low and
high temperatures, pH, and salinity, among other factors, are considered the most
important abiotic environmental variables that affect both plant physiology and
growth and the activity of plant beneficial microbes including PSM. Understanding
the impact of such environmental factors on structure and functions of PSM is
therefore extremely important for developing and modelling these micro-
phosphatic fertilizers for ultimate transfer to consumers. In order to obtain PSM
with high PS activity, it is important to analyse samples from different sources/
locations including extreme environments so that a better suited PSM could be
identified. A constant exploration of the natural microbial biodiversity of soil and
the optimization and fine-tuning (manipulation) of PS microbes are, therefore,
required for developing more proficient microbial P inoculants. No doubt, mani-
pulating PSM to acclimatize well to extreme environment is likely to hold the key
to improved plant nutrition under stressed environmental conditions and hopefully
increased crop yields in the sustainable crop production practices.
References
Acikel U, Er¸an M (2010) Acid phosphatase production by
Rhizopus delemar
: a role played in the
Ni(II) bioaccumulation process. J Hazard Mater 184:632-639
Ae N, Arihara J, Okada K, Yoshihara T, Johansen C (1990) Phosphorus uptake by pigeonpea and
its role in cropping systems of the Indian subcontinent. Science 248:477-480
Afzal A, Bano A (2008)
Rhizobium
and phosphate solubilizing bacteria improve the yield and
phosphorus uptake in wheat (
Triticum aestivum
). Int J Agric Biol 10:85-88
Ahmad E (2014) Functional diversity and interactive effect of plant growth promoting
rhizobacteria on performance of legumes. Ph.D. thesis, Aligarh Muslim University, Aligarh
