Agriculture Reference
In-Depth Information
capable of inhibiting the growth of phytopathogens (Khan et al.
2002
; Guo
et al.
2004
; Saravanakumar et al.
2007
; Khan et al.
2009
; Sambanthamoorthy
et al.
2012
); and (vi) providing resistance to drought, salinity, waterlogging and
oxidative stress (Alvarez et al.
1996
; Stajner et al.
1997
; Saleem et al.
2007
).
Therefore, the use of microphos in crop production is considered as an
environment-friendly alternative to further applications of mineral P fertilizers.
However, in order to produce microphos, the organisms with P-solubilizing ability
must be isolated and characterized. Subsequently, the microphos are tested both
under pot soil or field environment prior to their transfer to the practitioner/farmers
for application in agricultural practices.
1.2 Rationale for Using Microphos in Sustainable
Agriculture
In contemporary agricultural practices, millions of tons of agrochemicals including
P fertilizers are frequently but indiscriminately used to achieve optimum crop
yields. Such synthetic chemicals are, however, not completely used up by plants
and, hence, persist in different forms in soil. From here, they leach deep into the
grounds and disrupt the composition and functions of beneficial rhizosphere micro-
organism (Ai et al.
2012
), soil matrix (Ai et al.
2013
; Lemanski and Scheu
2014
)
and via food chain, the human health (Ayala and Rao
2002
). Furthermore, the
chemical fertilizers are used either alone, for example, single super phosphate
(Maheshwari et al.
2011
), or as mixture (Malhi et al.
2007
), for example,
diammonium phosphate (DAP), for enhancing crop production in different soil
ecosystems. The excessive use of agrochemicals is, however, posing some serious
threats to the very sustainability of the environments and is being considered as one
of the major problems around the world. So, due to the alarmingly very high costs
of fertilizers and some acute environmental hazards associated with the use of
synthetic fertilizers (L´pez-Bellido et al.
2013
), it has become increasingly impor-
tant to find some low-cost alternative like the use of renewable resources which
could both be inexpensive and could minimize the environmental threats (Bashan
1998
; Vessey
2003
; Adesemoye and Kloepper
2009
). In this context, the discovery
of plant growth-promoting rhizobacteria (Kloepper et al.
1986
; Ahemad and Khan
2011b
; Ahmad et al.
2013
; Oves et al.
2013
) and the preparation from PSM
(microphos) have provided some relief to the poor agronomic practitioners largely
due to: (i) low-cost technology with a high cost-benefit ratio, (ii) easy and abundant
availability of PSM, (iii) enhances plant growth and crop yields through increased P
supply and other growth regulators, (iv) reduces the environmental pollution caused
from the manufacturing of the fertilizers and chemicals used, (v) improves soil
health and conditioning, (vii) protects plants from pathogens damage and (viii)
helps plant to grow under stressed conditions. Therefore, the discovery of PSM and,
hence, the production of microphos have attracted greater attention of agronomists
