Soil Flora - Hemant Mahra Bsc.Ag IAAS, TU

3. 1.Soil Macroflora (Roots of higher plants)
 The dead plant contribute to the formation of soil
organic matter which provides food, energy and
nutrients to microorganisms and also higher plants –A
process of cycling of plant nutrients
Decay of plant roots add O.M. to soil, thereby changing
soil properties viz. soil aggregation, CEC, water & nutrient
retention capacity, etc. of soil.
While proliferating, the roots exert tremendous pressure
on surrounding particles. When roots decay, the vacant
space makes room for water & air to move it as well as
more food to the microbes, influencing thereby microbial
activity of soil.

5. 2.Microflora
 Micro flora of soil is an integral part of soil organic
matter.
 Soil bacteria and fungi are the start of the soil food
web that supports other organisms.
 Bacteria constitute the most abundant groups of
microorganisms in soil and the fungal population of
soils constitutes a very heterogenous group of
organisms.

9.  They are known for rapid proliferation. size varies from 0.5
to 1 micron (diameter) & 1 to 10 micron(length).
They have flagella & are motile.
They are most abundant in soil. 300 to 3000 kg of live
weight of bacteria/ha, 0.01 to 0.4% of total soil mass.
Shape may be round (cocci), rod like(bacilli) or spiral
(spirilla). In the soil the rod shaped ones seem to
predominate.
Bacterial population vary from few billion to three trillion in
each kilogram of soil.

14.  Actinomycetes
 Thread/filamentous. Next to bacteria in abundance
Prokaryotic in nature, classified with bacteria
Form mycelium and asexual spores like fungi
Cell wall composition same as bacteria i.e. peptidoglycan
Transitional group between bacteria & fungi
Active in degrading more resistant organic compounds

17.  Fungi
 A fungus is any member of the group of eukaryotic
organisms that includes microorganisms such as yeasts
and molds, as well as the more familiar mushrooms.
 These organisms are classified as a kingdom, which is
separate from the other eukaryotic life kingdoms of
plants and animals.
 Fungi (singular: fungus) are a kingdom of usually
multicellular eukaryotic organisms that are heterotrophs
(cannot make their own food) and have important roles
in nutrient cycling in an ecosystem.

18.  The five true phyla of fungi are the Chytridiomycota
(Chytrids), the Zygomycota (conjugated fungi),
the Ascomycota (sac fungi), the Basidiomycota (club
fungi) and the recently described Phylum
Glomeromycota.
 Fungi reproduce both sexually and asexually, and they
also have symbiotic associations with plants and
bacteria.
 Fungi dominants in acid soil
 Prefer acid medium (4.5 to 6.5). Some fungi can tolerate
even pH 9.0

24.  Algae is a simple, non-flowering, and typically
aquatic plant of a large group.
 It includes the seaweeds and many single-celled
forms.
 Algae are photosynthetic creatures, contain
chlorophyll but lack true stems, roots, leaves, and
vascular tissue.
 They are neither plant, animal or fungi.
 Many algae are single celled, however some species
are multicellular.
 Algae are protists with characteristics that resemble
those of plants. They are most commonly found in
aquatic environments
 Algae

28. There are seven major types of algae, each with distinct
characteristics:
 Euglenophyta (Euglenoids) are fresh and salt water
protists. Some euglenoids are autotrophic while others
are heterotrophic.
 Chrysophyta (Golden-brown algae and Diatoms) are
the most abundant types of single-celled algae
(approximately 100,000 different species).
 Pyrrophyta (Fire algae) are single-celled algae. They are
found in both the oceans and in fresh water. They use
flagella to move around.

29.  Chlorophyta (Green algae) typically live in freshwater.
Green algae have cell walls made of cellulose and are
photosynthetic.
 Rhodophyta (Red algae) are mostly found in tropical
marine environments. These eukaryotic cells do not
have flagella and centrioles, unlike other types of algae.
 Paeophyta (Brown algae) are among the largest species.
Examples include both seaweed and kelp.
 Xanthophyta (Yellow-green algae) are the least common
species of algae. They are single-celled and both
cellulose and silica make up their cell walls.