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Bio-Fertilizers
better source for protection and production of crops
M. Mithal Jiskani
Assistant Professor (Plant Pathology)
Faculty of Crop Protection, Sindh Agriculture University
Tandojam
“It is estimated that one billion people in the world suffer
from hunger and malnutrition. That's roughly 100 times as many
as those who actually die from these causes each year. About
24,000 people die every day from hunger or hunger-related
causes. This is down from 35,000 ten years ago, and 41,000
twenty years ago. Three-fourths of the deaths are children
under the age of five. Famine and wars cause about 10% of
hunger deaths, although these tend to be the ones you hear
about most often. The majority of hunger deaths are caused by
chronic malnutrition. Families facing extreme poverty are
simply unable to get enough food to eat” (www.biofertilizer.com).
 In order to increase crop production for fulfillment of
malnutrition requirements of the day by day increasing
population, the systems is relying exclusively on the use of
chemical fertilizers. Whereas, it is also proved that use of
chemical fertilizers and other pesticides has caused
tremendous harm to the environment by pollution and
contamination in water and soil and common men are suffering
by many means, because of the situation. Therefore, increase
in population, environmental pollution, contamination in water
and soil is the major concerns in today's world and there is a
reason to search for alternative methods of increasing plant
production in an eco-friendly manner, the adequate management
of natural, renewable resources and the reduction of chemical
inputs.
No doubt, all chemical fertilizers support the plant growth
and development, that results higher production, hence are
beneficial if used judiciously, but it is also very true that
the bio-fertilizers are totally safe, now used in most of the
countries because of their environmentally friendly fertilizer
property.
Actually, bio fertilizers are 100% natural and organic
fertilizers that enrich the nutrient quality of soil.
Bio-fertilizers are organisms that help to provide and keep in
the soil all the nutrients and microorganisms required for the
benefits of the plants (www.biofertilizer.com). The bacteria,
fungi and blue-green algae (cynobacteria) are the main sources
of bio-fertilizers. Symbiosis of these organisms with plants
is the most striking relationship, in which the partners
derive benefits from each other, without any damage/hazards.
The disease causing organisms (pathogenic bacteria, fungi etc)
are totally different to that of those which are
non-pathogenic and are used in bio-fertilizers.
The plants and trees (crops and fruit orchards) have a number
of relationships with fungi, bacteria, and algae, the most
common of which are with mycorrhiza, rhizobium, and
cyanophyceae. These are known to deliver a number of benefits
including plant nutrition, disease resistance, and tolerance
to adverse soil and climatic conditions. These techniques have
proved to be successful bio-fertilizers that form a health
relationship with the roots.
Bio-fertilizers are the most advanced bio technology can
increase the output, improve the quality and it is responsible
for agriculture environment. Bio-fertilizers are necessary to
support developing organic agriculture, sustainable
agriculture, green agriculture and non-pollution agriculture.
Bio-fertilizers contain a wide range of naturally chelated
plant nutrients and trace elements, carbohydrates, amino acids
and other growth promoting substances; acts as a soil
conditioner by stimulating microbial activity in the soil
which results in improved air-water relationships in soil,
improved fertility and makes soil less prone to compaction and
erosion. The researchers and growers, regularly using
bio-fertilizers in their fertility program reported increases
in yield, quality, shelf-life and resistance to environmental
stresses such as drought, extreme heat, early frost, pest and
disease problems.
Wu et al. (2005) evaluated the effects of four biofertilizers
containing an arbuscular mycorrhizal fungus (Glomus mosseae or
Glomus intraradices) with or without N-fixer (Azotobacter
chroococcum), P solubilizer (Bacillus megaterium) and K
solubilizer (Bacillus mucilaginous) on soil properties and the
growth of Zea mays. They reported that bio-fertilizer has been
identified as an alternative to chemical fertilizer to
increase soil fertility and crop production in sustainable
farming. This greenhouse study also indicated that the
application of biofertilizer containing mycorrhizal fungus and
three species of bacteria significantly increased the growth
of Z. mays. The use of biofertilizer (G. mosseae and three
bacterial species) resulted in the highest biomass and
seedling height. This was also observed that half the amount
of biofertilizer application had similar effects when compared
with organic fertilizer or chemical fertilizer treatments.
Microbial inoculum not only increased the nutritional
assimilation of plant (total N, P and K), but also improved
soil properties, such as organic matter content and total N in
soil. The arbuscular mycorrhizal fungi (AMF) had a higher root
infection rate in the presence of bacterial inoculation. By
contrast, the AMF seemed to have an inhibiting effect on the
P-solubilizing bacteria. The nutrient deficiency in soil
resulted in a larger population of N-fixing bacteria and
higher colonization of AMF.
Kumar et al. (2005) isolated broad-spectrum antagonistic
fluorescent pseudomonad strain PUPa3 from the rhizosphere soil
of rice and identified as Pseudomonas aeruginosa on the basis
of biochemical tests and by comparison of 16S rDNA sequences
and studied its antifungal activity and plant beneficial
traits. They reported that the antifungal metabolite produced
by PUPa3 has been identified as phenazine-1-carboxamide (PCN)
on the basis of NMR and MS data. Strain PUPa3 showed a
broad-spectrum antifungal activity towards a range of
phytopathogenic fungi. This bacterium also showed several
plant growth-promoting traits but did not show the traits
attributed to deleterious rhizobacteria. Present study also
reports the production of PCN as well as IAA by a saprophytic
P. aeruginosa strain PUPa3. Because of the production of
siderophore, growth hormone, protease and phosphatase and its
innate fungicidal potential, this strain can be used as
biofertilizer and antagonist against a range of
phytopathogenic fungi that infect rice, groundnut, tobacco,
chili, mango, sugarcane, tea, cotton and banana.
Nuruzzaman, et al. (2003) investigated the effect of
biofertilizers on morpho-physiological characters of okra
applying nine treatments such as T0 (control), T1 (Azotobacterf
biofertilizer), T2 ( Azospirillum biofertilizer), T3 (
Azotobacter+ Azospirillum biofertilizers), T4 (
Azotobacter+Cowdung 5 t ha-1), T5 ( Azospirillum+5 t ha-1
cowdung), T6 ( Azotobacter+ Azospirillum+5 t ha-1 cowdung), T7
(5 t ha-1 cowdung), and T8 (60% N). The experimental results
revealed significant variations among the treatments in
respect of morphological characters. Number of leaves per
plant, stem base diameter, root length, root dry weight, leaf
area index, and crop growth rate were larger in T4, T5, T6,
and T8 than the others. In all the parameters, T8 gave the
similar result with biofertilizers in combination with cowdung
treatments, and T7 was identical with T0 (control). These
experimental results revealed that morpho-physiological
characters of okra could be modified by the application of
biofertilizer+cowdung. However, biofertilizers+cowdung
treatments were comparable to T8 (60% N) in this study. This
suggests that T4 or T6 or T5 were more beneficial in
environmentally friendly okra cultivation and may be used as
an alternative of inorganic N by saving cost of production and
sustaining productivity.
Ozturk, et al. (2003) studied the yield response of a wheat (Kirik)
and a barley (Tokak 157/37) cultivar to inoculation with
Azospirillum brasilense sp. 246 and Bacillus sp. OSU-142 in
relation to three levels of N fertilization (0, 40, and 80 kg
ha-1) under field conditions. Seed inoculation with A.
brasilense Sp246 significantly affected yield and yield
components, both in wheat and barley. On average of years and
N doses, inoculation with A. brasilense Sp246 increased spike
number per m2, grain number per spike, grain yield, and crude
protein content by 7.2, 5.9, 14.7, and 4.1% in wheat and by
6.6, 8.1, 17.5, and 5.1% in barley, respectively, as compared
to control. Inoculation with Bacillus sp. OSU-142
significantly increased kernel number per spike in wheat, but
no significant effect was determined in the other
characteristics. Grain yields and yield components were also
higher at all levels of nitrogen fertilizer in the inoculated
plots as compared to the control. However, these increases
diminished at high fertilizer levels. These results suggest
that application of the growth promoting bacteria A.
brasilense Sp246 may have the potential to be used as a
biofertilizer for spring wheat and barley cultivation in
organic and low-N input agriculture.
Topoliantz, et al. (2002) conducted a biofertilizer
application assay for testing the effects of three different
organic amendments (manioc peels, sawdust and wood charcoal)
and the inoculation of the endogeic earthworm Pontoscolex
corethrurus on pod production of Vigna unguiculata subsp.
sesquipedalis and on soil chemical properties (pH, C, N, total
and exchangeable P and K). Pod production was highest with
manioc peels as available P increased in the soil. Wood
charcoal also had a beneficial effect on pod production as it
decreased acidity and increased the C: N ratio in the soil. In
sawdust-amended soil, pod production did not differ from that
in unamended soil. Inoculation of earthworms at a density of
80 sub-adults m-2 did not significantly affect either pod
production or soil nutrient content directly, although it
increased the positive effect of manioc peels on pod
production. Soil nutrient content, pod production and
earthworm density at the end of the experiment were negatively
correlated with soil moisture and positively with each other.
Despite the strong effect of moisture, this assay demonstrated
an interaction between the earthworm P. corethrurus and the
legume V. unguiculata sesquipedalis mediated by soil nutrient
content and organic matter inputs. We conclude that manioc
peels improved soil P availability and were an interesting
amendment for legume crops.
Bloemberg and Lugtenberg (2001) used plant-growth-promoting
rhizobacteria (PGPRs) as inoculants for biofertilizer
application, phytostimulation and biocontrol and reported that
the interactions of PGPRs with their biotic environment, for
example with plants and microorganisms, are often complex.
Substantial advances in elucidating the genetic basis of the
beneficial effects of PGPRs on plants have been made, some
from whole-genome sequencing projects. It emphasizes
developments in the field of microbial control of
phytopathogenic fungi.
Jeyabal and Kuppuswamy (2001) reported that investigations
were made to recycle agricultural and agro-industrial wastes
for the production of vermicompost using earthworms (Eudrilus
eugeniae), in a rice-legume (black gram) cropping. The study
showed that the integrated application of vermicompost,
fertilizer N and biofertilizers viz., Azospirillum and
phosphobacteria increased rice yield by 15.9% over application
with fertilizer N alone. The integrated application of 50% N
through vermicompost, 50% via fertilizer N and biofertilizers
recorded a grain yield of 6.25 and 0.51 t ha-1 in the rice and
legume, respectively. These yields were 12.2 and 19.9% higher
than those obtained with 100% fertilizer N alone. On average,
integrated application increased the N, P and K uptake by
15.3, 10.7 and 9.4%, respectively in rice over fertilizer N
alone. Organic carbon content in the residual soil after rice
was not depleted due to integrated application. The studies
indicate that integrated nutrition comprising vermicompost,
fertilizers N and biofertilizers could be applied to
rice-legume cropping system to achieve higher yields and
sustain soil health.
Galal et al. (2000) studied the potential of biofertilizers,
when the quantities of commercial fertilizers were reduced,
for optimal wheat production. N fertilizer was applied in
three treatments with one control, i.e. zero, full, half and
one-quarter rates, in the presence or absence of inocula.
Azospirillum brasilense strain Sp245 was used as a
biofertilizer. Generally, inoculation increased the
accumulation of shoot dry matter and grain yield by about 35%,
relative to the control treatment. Similar trends were
observed in the case of N and P uptake by shoots and grains,
as well as the efficient use of both, where inoculation
increased the acquisition of the two elements as compared with
the uninoculated plants. The obtained data showed that N2
fixed by shoots and grains ranged from 2 to 10 kg N ha-1 and
from 8 to 19 kg N ha-1, respectively. With respect to fixed
N2, the best treatment was inoculation combined with the
one-fourth dose of N, followed by inoculation combined with
half of the recommended N dose. Most of the fixed N was
utilized by grains and the results clearly reflected the
negative effect of high N fertilizer rates on biological N
fixation. It is obvious that inoculation, in general, enhanced
the N fertilizer utilized by both shoots and grains of wheat
plants. In conclusion, the application of biofertilization
technology to a coarse-textured soil with low fertility had a
positive effect on plant growth, N gained from the air and
enhancement of fertilizer N uptake (apparent recovery
fraction).
Victor and Reuben (2000) studied the effects of nitrogenous
(inorganic) fertilizers, organic manures and blue-green algae
(BGA) biofertilizer on mosquito populations (Diptera:
Culicidae) in Oryza sativa fields, with particular attention
to Culex vishnui, C. pseudovishnui and C. tritaeniorhynchus.
The application of urea, a nitrogenous fertilizer, in rice
fields significantly increased the grain yield and the
population densities of mosquito larvae and pupae (anophelines
as well as culicines) in a dose-related manner. Fields treated
with inorganic fertilizers (N, P, K) had significantly higher
population densities of mosquito immatures than fields treated
with organic manures (farmyard manure and green manure).
Without nitrogenous fertilizer, BGA increased paddy yield
without enhancing mosquito production. Therefore, the use of
BGA with less nitrogenous fertilizer is recommended, which is
beneficial economically and agronomically to the farming
community and also significantly reduces mosquito production
in rice fields.
According to reports, bio-fertilizers contain a variety of
beneficial micro-organisms and enzymes which accelerates and
improves plant growth and prevent plants from pests and
diseases. Completely fermented organic matters, present in
bio-fertilizers improve the physical properties of soils,
enrich air aeration, water and nutrients retention capacity
and reduce acidity. Considerable amount of 3 major elements
such as N, P, K, Mg and trace elements increases fertilizer
efficiency in soil as well as minimize leaching due to
rainfall. The hardpans problems in soil due to excessive
application of agrochemicals and chemical fertilizer also
overcome and health and hardiness in a wide variety of plants
also improved with bio-fertilizers, by supplying the
beneficial microorganisms, humic acid and organic fungi and
actinomyces, humic and fulvic acids to the plant root zone.
The beneficial microorganisms present in bio-fertilizers
reduce plant stress and disease by competing with plant
pathogens; whereas, humic acid is a plant bio-stimulant and
can increase soil fertility, enhance mocrobial activity and
reduce water evaporation.
Bio-fertilizers provide both the macro as well as micro
nutrients, required for healthy growth. Therefore, improves
yields and the quality of agricultural crops, reduces the
overall cost of fertilizer and the number and type of
pesticide sprays, based on yield, because increased plant
vigor and a greater resistance to disease, insect attack and
frost due to increased protein, found within the plant.
Bio-fertilizers are free of unpleasant odors, is a naturally
balanced complete plant food, improved seed germination and
thicker root development, increased bloom set, size of flowers
and fruit and the storage life of fruits and vegetables by
retarding the loss of protein, chlorophyll and RNA in produce.
Now a day, bio-fertilizers are widely used in several
countries with excellent results in all kinds of plants and
trees. The studies on all concerned aspects are still needed
in Pakistan, however, there is a dire need to make
availabilities of bio-fertilizers and transfer technology to
the growers at their door step, whatever has been done
locally.
References:
Bloemberg, G. V. and B. J. J. Lugtenberg, 2001. Molecular
basis of plant growth promotion and biocontrol by
rhizobacteria. Current Opinion in Plant Biology, 4 (4):
343-350
Galal, Y. G. M., I. A. El-Ghandour, S. S. Aly, S. Soliman and
A. Gadalla, 2000. Non-isotopic method for the quantification
of biological nitrogen fixation and wheat production under
field conditions. Biology and Fertility of Soils, 32 (1):
47-51
Jeyabal, A. and G. Kuppuswamy, 2001. Recycling of organic
wastes for the production of vermicompost and its response in
rice-legume cropping system and soil fertility. European
Journal of Agronomy, 15 (3): 153-170
Kumar, R. S., N. Ayyadurai, P. Pandiaraja, A.V. Reddy, Y.
Venkateswarlu, O. Prakash and N. Sakthivel, 2005.
Characterization of antifungal metabolite produced by a new
strain Pseudomonas aeruginosa PUPa3 that exhibits
broad-spectrum antifungal activity and biofertilizing traits.
Journal of Applied Microbiology, 98 (1): 145-154
Nuruzzaman, M., M. Ashrafuzzaman, M. Z. Islam and M. R. Islam,
2003. Field efficiency of biofertilizers on the growth of okra
(Abelmoschus esculentus [(L.) Moench]). Journal of Plant
Nutrition and Soil Science, 166 (6): 764-770
Ozturk, A. and O. Caglar, 2003. Yield response of wheat and
barley to inoculation of plant growth promoting rhizobacteria
at various levels of nitrogen fertilization. Journal of Plant
Nutrition and Soil Science, 166 (2): 262-266
Topoliantz, S., J. F. Ponge, D. Arrouays, S. Ballof and P.
Lavelle, 2002. Effect of organic manure and the endogeic
earthworm Pontoscolex corethrurus (Oligochaeta:
Glossoscolecidae) on soil fertility and bean production.
Biology and Fertility of Soils, 36 (4): 313-319
Victor, T. J. and R. Reuben, 2000. Effects of organic and
inorganic fertilizers on mosquito populations in rice fields
of southern India. Medical and Veterinary Entomology, 14 (4):
361-368
Wu, S. C., Z. H. Cao, Z. G. Li, K. C. Cheung and M. H. Wong,
2005. Effects of biofertilizer containing N-fixer, P and K
solubilizers and AM fungi on maize growth: a greenhouse trial.
Geoderma, 125 (1/2): 155-166
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