Agriculture Reference
In-Depth Information
the dry matter accumulation by 99 %, while it was 94 % by strain CDB 35. Grain
yields of inoculated maize increased by 85 % and 64 %, following EB 67 and CDB
35 application, respectively. When applied as mixture with arbuscular mycorrhizal
(AM) fungi
G. intraradices
, the PSB
Pseudomonas fluorescens
had a positive
impact on plant growth, nutrient uptake, grain yield, and yield components in
maize plants. Composite inoculation of the two cultures significantly increased
grain yield, yield components, harvest index, grain N and P, soil available P, and
root colonization percentage under water stress conditions. However, some of the
assayed characteristics under well-watered conditions were nonsignificantly higher
in chemical fertilizer treatment compared to those observed for dual inoculation
treatments. However, the effect of sole application of
P. fluorescens
(Pf) was poor
relative to the composite application of AM fungus with PSB or single application
of AM fungi. The measured parameters of inoculated plants were in general higher
than uninoculated plants under water-deficit stress conditions. In addition, the
characteristics determined for co-inoculated plants grown under severe water-
stressed conditions were significantly lower than co-inoculated plants grown
under well-watered and moderate-stressed conditions. This finding suggested that
PSB can interact positively with other organism like AM fungi as observed in this
study and can be used to facilitate plant growth and P uptake by maize plants,
leading to plant tolerance improving under water-deficit stress conditions
(Ehteshami et al.
2007
). In another study, Yazdani et al. (
2009
) investigated the
effect of PS bacteria such as
A. coroocoocum
,
A. brasilense
,
P. putida
, and
B. lentus
on yield and growth components of
Zea mays
where they observed an increase in
row number, ear weight, grain number/year, grain yield, biological yield, and
harvest index relative to control.
8.5 Conclusion
Nitrogen and phosphorus are the two essential nutrients for plant growth and
development. The extensive use of chemical fertilizers to provide these nutrients
in agriculture is currently under debate due to environmental concern, and questions
are raised regarding the consumer's health. Recent advancements in the field of
biofertilizers offer an opportunity to environmentally friendly and sustainable
agricultural practices to reduce dependence on chemical fertilizers and thereby
decrease adverse environmental effects. Phosphate-solubilizing bacteria in associ-
ation with N
2
fixers and AM fungi can lead to increased legume growth through a
range of mechanisms which could be of great practical value in sustainable,
low-input agricultural cropping systems that rely on biological processes to main-
tain soil fertility and plant health. Although there are numerous reports highlighting
interactions among P-solubilizers, N
2
fixers, and mycorrhizal fungi, the underlying
mechanisms behind these associations are in general not conclusive. Moreover, the
development of effective microbial inoculants for raising the productivity of
legumes remains a major scientific challenge. And hence, functional properties of
