Soil organic increment

1. Soil Organic
Increment
Submitted To,
Dr. Shakil Ahmed
Presented By,
Atika Noor
Mphil-01
Mphil Botany 1st Semester
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2.  Introduction
 Soil composition
 The Global carbon cycle
 Components of Organic matter
Contents
 Crop residues
 Animal manure
 Humus
 Green manure
Carbon sources
Component of plant residues
Decomposition of organic matter
Factor controlling rate of
decomposition
Factors affecting organic matter
content
Benefits of soil organic matter
Influences of organic matter on soil
properties
Conclusion
References
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3. Soil organic matter is a complex and
varied mixture of organic substances.
It can be defined as any material
produced originally by living organisms
(plant or animal) that is returned to the
soil and goes through the
decomposition process.
Organic matter makes up just 2–10%
of the soils mass.
Introduction:
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4. Influence of Organic Matter on Soil:
Organic materials in soil exert a dominant influence on soil
Physical
Chemical
Biological properties
especially in the surface horizons
Soil organic matter provides much of soil cation exchange
capacity and water holding capacity.
Soil organic matter are largely responsible for the formation and
stabilization of soil aggregates
Soil organic matter also contains larger quantities of plant
nutrients.
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5. Composition of Organic Matter
 Soil microorganisms and fauna make up a relatively small portion of total soil organic
matter (1-8%).
 Cellulose generally accounts for the largest proportion of fresh organic material
•decays rapidly
•need N for decay
 Lignin decomposes slowly
•nutrients bound in lignin forms are not available for plant growth
•seldom find calcareous soils with high organic matter.
 Polysaccharides decompose rapidly in soils and serve as an immediate source of C for
microorganisms.
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6. Global
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7. Cycling of Carbon In an Ecosystem.
Plants take in
carbon
dioxide from
atmosphere
Respiration
which added to
soil as soil litter
(including crop
residues)
Some plant
material may be
eaten by animals
(including
humans)
Once deposited in
the soil these plant
and animal tissues
are metabolized
(digested) by soil
organisms
Microbial
metabolism in
the soil
produces some
organic
compounds
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8. Crop residues
Animal manure
Humus
Green manure
Components Of Organic Matter
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9. Two types of agricultural crop residues.
Field residues are materials left in an agricultural
field or orchard after the crop has been harvested
These residues include stalks stems, leaves,
and seed pods
Process residues are materials left after the crop is
processed into a usable resource
Crop Residues:
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Fig: Crop Residues

10. Animal Manure:
Organic matter derived from
animal feces.
Farmyard manure (FYM) or
Farm slurry (liquid manure)
 Source of carbon, Nitrogen and
Urea and other organic
components to soil.
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Fig: Farmyard Manure.

11. Fully decomposed, most reactive and
stable organic matter
Humus is the dark organic matter that
forms in the soil when plant and animal
matter decays
It is also used to describe a topsoil horizon
that contains organic matter
Increase water holding capacity and good
storing nutrients to soil.
Humus:
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12. In agriculture, green manure is created by
leaving uprooted or sown crop parts on a
field
The plants used for green manure are
often called cover crops
Leguminouas plants such as clover are
often used for this, as they fix nitrogen
using Rhizobia bacteria in specialized
nodes in the root structure
Roughly fallen leaves to soil.
Green Manure:
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Fig: Green crop manure

13. The water content of most plant residues is 75%.
The dry matter 25% which consists of elemental composition
mainly of carbon 42%, oxygen 42% and hydrogen 8%.
 And Organic compounds found in plant residues include
Carbohydrates
Fats
Lignin
Proteins
Sugar and starch
Composition of Plant Residue
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14. Decomposition Of Organic Matter:
 Decomposition is a biological process that
includes the physical breakdown and
biochemical transformation of complex
organic molecules of dead material into
simpler organic and inorganic molecules
 The ultimate products of decomposition
are simple molecules, such as carbon
dioxide and water
 The rate of decomposition of organic
matter depends on the soil's
temperature, moisture, aeration, pH and
nutrient levels.
Decomposition
processes
3. Chemical
Hydrolysis oxidation
reduction
1.
Biological
2. Enzymatic
Protein molecule
Catalyst
Increases
reaction rate
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15.  Environmental
conditions in the soil.
 Neutral pH,
 Aeration,
 Sufficient soil moisture,
 Warm temp (25-350 C)
 Quality of added
residues as a food
source for living
organisms
 Physical factors
influencing residual
quality such as when
they are out of reach
of soil organisms,
particle size
Factors Controlling Rates Of Decomposition
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16. 1.Type of
vegetation
Grassland with
high percentage.
Forest with
lower one.
2. Drainage
Soil organic
matter is usually
higher in poorly-
drained soils
because of limited
oxidation, which
slows down the
overall biological
decomposition
process.
3. Tillage
Soils that are tilled
frequently are often low
in organic matter.
Plowing and otherwise
tilling the soil increases
the amount of air in the
soil, which increases
the rate of organic
matter decomposition.
Factors Affecting Organic Matter Contents
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17. Enhances aggregate stability,
improve water infiltration and
soil aeration
Improves water holding
capacity
Reduces the stickiness of clay
soils making them easier to till
Reduces surface crusting,
facilitating seedbed preparation
Physical Benefits of Soil Organic Increment
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Fig: Enhances aggregate stability

18.  Provides food for the living
organisms in the soil
 Enhances soil microbial
biodiversity and activity which can
help in the suppression of
diseases and pests
 Enhances pore space through
the actions of soil microorganisms
Biological Benefits of Soil
Organic Increment:
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Fig: Healthy Soil with Organic Increment.

19.  Increases the soil’s CEC or its ability to hold onto and
supply over time essential nutrients such as calcium,
magnesium and potassium
 Improves the ability of a soil to resist pH change; this
is also known as buffering capacity
 Accelerates decomposition of soil minerals over time,
making the nutrients in the minerals available for plant
uptake.
Chemical Benefits of Soil Organic Increment
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20. 20

21. If plant and animal residues and wastes added to
soil then they protect the soil surface from solar
energy and rain droplets.
Increased buffering capacity
Reduction of evaporative water losses
Less water needed for irrigation
Greater plant production
Increased water availability to plants
Influences Of Soil Organic Increment On
Soil Properties
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Conti….

22. Increased water infiltration
Less surface runoff water losses
Less water pollution
Enhanced microbial function
such as N fixation,
decomposition
Less fertilizers use required
Moderation soil temperature
extremes
Increased water holding capacity
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Conti….
Fig: water Holding Capacity in Different Soils

23. Increased competition and
antagonism against plant pests
More adsorption of organic
compounds
Inactivation of toxins, pesticides
Production of humic substance
Increased adsorption capacity
More stable pH
More retention of Ca, Mg, K and
micronutrients
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Conti…. Fig: Ionic Exchange in Organic Soil

24. Darker soil color due to humic
substance
Increased gas exchange
Better aeration and oxygen supply to
roots
Increased aggregate stability
Less soil erosion
Less land degradation
Increased metal ion chelation
Increased mineralization
Increased availability of Fe, Mn, Cu, Zn
Soil without
organic
increment
Soil with
organic
incremnt
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25. Cover Crops
Increase Nutrient
Cycling
Increase Water
Conservation
Increase Organic
Matter
What we have
to do…!!!
Put the skin back on
the soil using no-till
and mixed species
cover crops, which will
decrease erosion and
inputs.
Be innovative and
tenacious
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26.  Organic matter is a complex and dynamic soil component
that exerts a major influence on soil behavior, properties and
function in ecosystem.
 Because of enormous amount of carbon stored in soil
organic increment and dynamic nature of this soil
component and soil management may be important tool for
moderating the greenhouse effect.
 Soil organic matter contributes to soil productivity in many
different ways.
 Soil organic increment improves soil structure, water-
holding capacity, soil stability, nutrient storage and oxygen-
holding capacity, plant growth, and yield etc.
Conclusion:
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27.  Abbas, T. S., Ahmed, R., Anwar, M. M., Khan, M. R., Bilal, R. M., and Pervez, M.A. 2009.Effect of
humic acid on some morpho-physiological and bio-chemical attributes of Kinnow Mandarin (Citrus
reticulata Blanco). Horticulture Science, 44(4): 1034.
 Asik, B. B., Turan, M. A., Celik, H., and Katkat, A. V. 2009. Effects of humic substance on plant growth
and mineral nutrient uptake on wheat (Triticum durum cv. Salihli) under salinity conditions. Asian Journal
of Crop Science, 1(2):87-95.
 Barber, S. A. 1984. Soil Nutrient Bioavailability: A Mechanistic Approach. New York: Wiley.
 Bell, M.J., Moody, P.W., Connolly, R.D. & Bridge, B.J. 1998. The role of active fractions of soil organic
matter in physical and chemical fertility of Ferrosols. Aust. J. Soil Res., 36: 809-819.
 Bell, M.J., Moody, P.W., Yo, S.A. & Connolly, R.D. 1999. Using active fractions of soil organic matter as
indicators of the sustainability of Ferrosol farming systems. Aust. J. Soil Res., 37: 279-287.
 Brady, N. C. 2008. The Nature and Properties of Soils. New York: Macmillan Publishing Co., 14 edi.
S591.B79.
 Jain, T.B., Graham, R.T. and Adams, D.L. 1997. Carbon to organic matter ratios for soils in Rocky
Mountain coniferous forests. Soil Science Society of America Journal 61: 1190-1195.
References:
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