the use of biofertilizer in developing countries is not a clear matter, this presentation is presented to expose the value and how to use biofertilizers.

1. The Use Biofertilizers as an
Element of Soil Health
Sustainability
By
Buyegi George

2. Introduction
Bio-fertilizers are substances that colonizes
rhizosphere or the interior of the plant.
They make use of soil living microorganisms and
supply important nutrients such as nitrogen and
phosphorus (Bhattacharjee and Dey 2014).

3. Intro………
Plants need such nutrients for their growth and
development.
Therefore bio-fertilizers add these nutrients through
Nitrogen (N) fixation, phosphorus (P) solubilisation,
mobilizing and stimulation of plant growth through
plant growth promoting substances (Bhattacharjee and
Dey 2014; Siddiqui 2006).

4. Intro……………..
Bio-fertilizers are not harmful to the soil or
plants, they are renewable and environmental
friendly,
They can be used as an alternative to chemical
fertilizers.
They restore the soils natural nutrient cycle
They build soil organic matter and
Promote plant growth and enhance soil health and
sustainability.

5. Types of bio-fertilizers
Nitrogen fixing biofertilizer; Rhizobium,
Azotobacter, Azospirillum, Algal biofertilizes.
Phosphorus solubilising biofertilizer; Bacillus,
Pseudomonas, Aspergillus.
Phosphorus mobilizing biofertilizer; Mycorrhiza.
Plant growth promoting biofertilizer;
Pseudomonas

6. Nitrogen Fixing Biofertilizers
Nitrogen is highly needed in growth and
development of plants.
A soil with nitrogen is a healthy soil.
Biofertilizers ensure availability of
nitrogen in the soil for the plants to up
take.

7. Rhizobium
Rhizobium fixes nitrogen (N) from 50- 100
kg/ha (Mahdi et al. 2010), they fix nitrogen for
leguminous plants such as soybean, groundnuts
and fodder legumes such as Medicago sativa.
Rhizobium can fix atmospheric nitrogen in
symbiotic interaction with legumes therefore,
once legume plants are unavailable in the field
the fixation of N by rhizobium is limited.

8. Rhizobium…
Rhizobium colonizes the roots of a plant and form
nodules using strains of rhizobia which in turn act as
ammonia production factories (Mahdi et al. 2010).
Rhizobium inoculation is an agronomic practice that
ensure the availability of N in the soil, it is used
instead of application of N fertilisers.
It increases yield especially in soils that N is limited

9. Azotobacteria
They are mostly found in neutral and alkaline soils.
Unlike Rhizobium, Azotobacteria occur in non-
leguminous plants such as rice, maize, sugarcane,
vegetables and plantation crops subsequently they do
not produce visible nodules.
They colonize roots and can penetrate the root tissues
and live in harmony with the plant.
The isolated culture of Azotobacter fixes about 10 mg
nitrogen g-1 of carbon source under in vitro conditions
(Mahdi et al. 2010).

10. Azotobacteria
With strain of Azotobacteria, anti-fungal
antibiotics are produced and these inhibit the
growth of pathogenic fungus in the roots
resulting to prevention of seedling death.
Azotobacteria protect plants from Fusarium,
Alternaria and Helminthosporium pathogens
(Mahdi et al. 2010).

11. Azospirillum
They fix 20-40% of N/ha and produces
substances for growth regulation.
They form an interaction with most of the C4-
dicarboxyliac pathway of photosynthesis plants.
Mohammadi & Sohrabi (2012) explains that
Azospirillum can fix atmospheric nitrogen
without symbiosis, therefore these biofertilizers
are non-symbiotic.

12. Azospirillum
Uses ammonium salts as a nitrogen source
(Gharib, Moussa, and Massoud 2008).
They can grow and fix nitrogen in salts and
organic acids and therefore inoculation of such
biofertilizers is recommended for maize,
sugarcane, sorghum, pearl millet (Mahdi et al.
2010).
They can increase up to 30% of yield

13. Acetobacteria
It is found mainly in sugarcane and fixes up to
70% of the N requirements in sugarcane (Rai
2005).
They are non-symbiotic and grows inside the root
as well as stems to some extent.
Fixes the atmospheric nitrogen and this benefits
the crop (Deshmukh, Khobragade, and Dixit
2007).

14. Phosphorus solubilising and mobilizing
biofertilizer
Phosphorus is another important nutrient that
is limited in its availability to plants
following nitrogen.
This is because, plants can only uptake
soluble Phosphorus while the available one is
usually insoluble.

15. Therefore, phosphorus solubilizing biofertilizers
converts insoluble phosphorus into soluble form
HPO4
2- and H2PO4 by secreting acid, this soluble
P will be available, and it is mainly done in the
rhizosphere.
This is an alternative to phosphorus fertilizers.
Bacteria are the most phosphorus solubilizing
agents when compared to Fungi

16. Strains from bacterial genera Pseudomonas,
Bacillus, Rhizobium and Enterobacter along
with Penicillium and Aspergillus fungi are
the most powerful P solubilizers.
Bacillus can form a stable and extensive
biofilm and secrete many antifungal
compounds, such as surfactin, bacillomycin
and macrolactin, that protect plants against
attack by soil-borne pathogens.

17. Most species of Bacillus can effectively inhibit
the mycelial growth of Fusarium oxysporum.
Pseudomonas species are known to increase the
number of nodules, dry weight of these nodules,
yield components grain yield, nutrients
availability especially phosphorus, and uptake are
also increased in crops such as soybean.
 Siddiqui (2006) reports that Pseudomonas
species reduced Trichodorid nematodes density in
potato by 56% to 74%.

19. phosphorus mobilization
 The activity of phosphorus
mobilization can be carried out
by Mycorrhiza which are the
root fungus.
 Between plants and Mycorrhiza
there is a symbiotic interaction
whereby the fungus obtains
needed carbohydrates from the
plant and in exchange the plant
gets the necessary nutrients
especially phosphorus
nutrients
carbohydrates
Stress resistance
Benefit for both partners

20. Plant growth promoting biofertilizer
Most of the microorganisms are used in plant growth
promotion.
The symbiotic relationship between bacteria, fungi with
their host plants mentioned before are all promoting
growth.
There are two categories of relationship namely
rhizospheric and endophic.
Rhizospheric relationship happens in the rhizosphere and
roots of the plant and the host plant form visible nodules
to the plant.

21. Endophic relationship occur in the tissues of the plant
and they do not form visible nodules.
These relationships are beneficial to both plants and
microorganisms as they live with harmony by
supporting each other’s lives.

22. These biofertilizers differ in their mechanism
of plant growth promotion but generally
influence growth via P solubilisation, nutrient
uptake enhancement, or plant growth
hormone production (Bhattacharjee and Dey
2014).
Some of the microorganisms promote growth
by inhibiting pathogen infection.

23. Benefits of using biofertilizers.
They are environment friendly unlike chemical
that usually pollute the environment and
eventually kills the microorganisms in the soil.
They protect plants from plant pathogens
example are the Azotobacteria and Bacillus
biofertilizers.
They increase yield for most crops by assuring
availability of necessary nutrients to the plant.

24. benefits,……………
Accelerate plant growth through good interaction
with the plant.
Soils retain fertility because, soil will be free from
chemicals.
They are cheap when compared to chemical
fertilizers
They may protect the plants from stressful
conditions such as drought

25. What are the limitations of
using Bio-fertilizers?

26. Conclusion
The use of bio-fertilizers is essential for soil health.
When compared to chemical fertilizers it is better to
use bio-fertilizers.
Bio-fertilizers makes sure nutrients are up taken by
the plants. Some nutrients that are limited for plants
are made available by the bio-fertilizers.
Nitrogen is limited in most soils but with
biofertilizers it is made available through nitrogen
fixing microorganism.

27. Conclusion…….
Apart from nitrogen, phosphorus also which
is usually in insoluble form is converted to
soluble form, a form that is available for
plants to uptake. All these promote soil health
sustainability and plant growth.
Moreover, plants are even protected from
notorious pathogens through biofertilizers.

28. Summary of biofertilizers classification

29. REFERENCES
 Bhattacharjee, Ritika, and Utpal Dey. 2014. “Biofertilizer, a Way towards Organic
Agriculture: A Review.” African Journal of Microbiology Research 8(24): 2332–42.
 Deshmukh, AM, RM Khobragade, and PP Dixit. 2007. Handbook of Biofertilizers and
Biopesticides. http://agris.fao.org/agris-search/search.do?recordID=US201300128985.
 Gharib, Fatma A., Lobna A. Moussa, and Osama N. Massoud. 2008. “Effect of Compost and
Bio-Fertilizers on Growth, Yield and N Essential Oil of Sweet Marjoram (Majorana
Hortensis) Plant.” International Journal of Agriculture and Biology 10(4): 381–87.
 Mahdi, S. Sheraz et al. 2010. “Bio-Fertilizers In Organic Agriculture.” Journal of Phytology
2(10): 42–54.
 Mohammadi, Khosro, and Yousef Sohrabi. 2012. “BACTERIAL BIOFERTILIZERS FOR
SUSTAINABLE CROP PRODUCTION : A REVIEW.” ARPN Journal of Agricultural and
Biological Science 7(5): 307–16.
 Rai, M K. 2005. Microbial Biofertilizers. ed. M. K. Rai.
 Siddiqui, Zaki A. 2006. PGPR: Biocontrol and Biofertilization Biocontrol and
Biofertilization.

30. Thanks

31. In general, there are 6 major steps in making bio
fertilizer:
I. Choosing active organisms, For example, decide
to use whether organic acid bacteria or
nitrogen fixer or the combination of some
organisms.
II. Isolation and selection of target microbes,
A step of separating target microbes from their
habitat.
Usually organism are isolated from plant roots.

32. III. The isolated organisms will be grown on
Petri plate, shake flask and then glasshouse
to select the best candidates.
IV. It is also important to decide form of bio
fertilizer product wisely so that the right
carrier material can be determined. If it is
desired to produce bio fertilizer in powder
form, then tapioca flour or peat are the right
carrier materials.

33. IV. Selection of propagation method, mainly
to find out the optimum condition of
organism. This can be achieved by
obtaining growth profile at different
parameter and conditions.
V. Prototype is made and tested
VI. Bio fertilizer is tested on large scale at
different environment to analyze its
effectiveness and limitability at different
surrounding