6. Benefits
1.Nutrient Supply
Organic matter is a reservoir of nutrients that can be
released to the soil. Each percent of organic matter in
the soil releases 20 to 30 pounds of nitrogen, 4.5 to
6.6 pounds of P2O5, and 2 to 3 pounds of sulfur per
year.
The nutrient release occurs predominantly in the
spring and summer, so summer crops benefit more
from organic-matter mineralization than winter crops.
Organic matter is the source of 90-95 percent of the
nitrogen in unfertilized soils.
7. 2.Contribution to CEC
Organic matter contributes to the cation
exchange capacity, often furnishing 30-70
percent of the total amount. The large
available surfaces of humus have many cation
exchange sites that adsorb nutrients for
eventual plant use and temporarily adsorb
heavy metal pollutants ( lead, cadmium, and
the like), which are usually derived from
applied waste waters. Adsorption of these
probably helps clean contaminated water.
8. 3.Chelate
Organic matter acts as a chelate. A ligand is any
organic compound that can bond to a metal
(usually iron, zinc, copper, or manganese) by
more than one bond and form a ring or cyclic
structure by that bonding, called a chelate
(keylate). The soluble chelates probably help
mobilize these micronutrients metal ions
increasing their availability to plants and general
mobility in soils. The chelate mechanisms are not
fully known at present.
11. 1.Water Holding Capacity
2. Organic matter behaves somewhat like a
sponge, with the ability to absorb and hold up
to 90 percent of its weight in water. A great
advantage of the water-holding capacity of
organic matter is that the matter will release
most of the water that it absorbs to plants. In
contrast, clay holds great quantities of water,
but much of it is unavailable to plants.
12. 2. Soil Structure Aggregation
Organic matter causes soil to clump and form soil aggregates, which improves
soil structure. With better soil structure, permeability (infiltration of water
through the soil) improves, in turn improving the soil's ability to take up and
hold water.
Soil structure is defined by the way individual particles of sand, silt, and clay are
assembled. Single particles when assembled appear as larger particles. These are called
aggregates
Classes and Types of soil structure
1. Very fine or very thin;
2. Fine or thin;
3. Medium;
4. Coarse or thick;
5. Very coarse or very thick.
13. 3.Soil Quality
• Soil quality is the capacity of soils
within landscapes to sustain biological
productivity, maintain environmental
quality, and promote plant and animal
health.
• Protecting soil quality like protecting
air quality and water quality should
be fundamental goal of our Nation’s
Environmental Policy
http://www.directs
eed.org/soil_qualit
y.htm
http://www.nrsl.umd.edu/research/NRSLResearchAreaInfo.cfm?ID=14
Poor Good
14. 4. Erosion Prevention
This property of organic matter is not widely known. Data used in the
universal soil loss equation indicate that increasing soil organic matter
from 1 to 3 percent can reduce erosion 20 to 33 percent because of
increased water infiltration and stable soil aggregate formation caused by
organic matter.
Most soil organic matter is in the topsoil. When soil erodes through water
movement, organic matter is removed with it. Appropriate tillage practices
particularly on sloping soils can reduce erosion and organic matter losses
such as contour ploughing.
15. 5. Mulch
When left on top of soil as a mulch, organic matter reduces erosion, shades
the soil (which prevents rapid moisture loss), and keeps the soil cooler in
very hot weather and warmer in winter.
16. 6.Compaction
• Higher organic matter levels tend to reduce the risk of soil compaction. Soil compaction is the
compression of soil due to outside pressure. The effect of soil compaction is an increase in
the density of a soil and a corresponding reduction in the amount of air present in the spaces
between soil particles. This process can be caused by a number of factors and may be
harmful or beneficial depending on the circumstances.
• Reasons to Avoid Soil Compaction
1. Causes nutrient deficiencies
2. Reduces crop productivity
3. Restricts root development
4. Reduces soil aeration through reduce the cultivation.
5. Decreases soil available water
6. Reduces infiltration rate
7. Increases bulk density
8. Increases sediment and nutrient losses
9. Increases surface runoff
10. Damages soil structure ,through reroute the traffic.
• 11. Breakup the hard layers.
• 12.Amend the soil .
17. 7. Reduced Surface Crusting
• Higher organic matter levels tend to reduce
the risk of soil capping particularly on fine
textured soils through an improved soil
structure.
18. 8.Porosity
• Porosity or pore space refers to the volume of soil voids that can be filled by water
and/or air. It is inversely related to bulk density. Porosity is calculated as a
percentage of the soil volume:
• Bulk density x 100 = % solid space
Particle density
• 100% – % Solid Space = Percent Pore Space
• Loose, porous soils have lower bulk densities and greater porosities than tightly
packed soils. Porosity varies depending on particle size and aggregation. It is
greater in clayey and organic soils than in sandy soils. A large number of small
particles in a volume of soil produces a large number of soil pores. Fewer large
particles can occupy the same volume of soil so there are fewer pores and less
porosity.
• Pores of all sizes and shapes combine to make up the total porosity of a soil.
Porosity, however, does not tell us anything about the size of pores.
•
19. HUMUS
• Newly-formed humus=
• a) combination of
resistant materials from
the original plant tissue,
• b) compounds synthesized
as part of the
microorganisms' tissue
which remain as the
organisms die. (Fulvic and
Humic Acid)
• humus is mostly resistant
to further microbial
attack- N and P are
protected from ready
solubility
Leaf Humus
20. 9.Humus
Humus buffers the soil against a rapid change in
acidity, alkalinity, and salinity; and damage by
pesticides and toxic heavy metals.
Rachel says, "Humus is as good as it gets,
nutritionally. However, humus cannot support
healthy life on its own. It should make up only a
certain percentage of ideal soil. Colorado State
University has compiled a comprehensive guide
to identifying the composition of your soil, which
will help you figure out how much humus you
need."
21. Ingredients of Humus
• Healthy humus contains everything a plant needs
to thrive. Nitrogen and oxygen are present in
abundance, along with various amounts of
potassium, magnesium and other minerals.
Adding 1 cubic foot of clay every 3 or 4 months
will help infuse trace metals and other inorganic
compounds as well as naturally regulating the
acidity of the humus soil. In all, humus contains
more than 25 minerals and nutrients that plants
need for proper growth.
22. Humus is Alive
• Humus is not just soil, it is a community of living
things. Organic matter is a breeding ground for
many types of microbes, including bacteria and
fungi which break down plant material, and for
other microorganisms that help plants roots
absorb necessary nutrients. Earthworms have
long been known to loosen the soil for plant
roots. Recent research indicates that earthworms
may serve to eliminate unwanted pathogens from
the soil as well.
23. Stable Organic Matter -Humus
• Thus, soil organic
compounds become
stabilized and resistant to
further changes by
microorganisms
• Stabilized organic matter
acts like a sponge and can
absorb six times its
weight in water
24. Humus consists of different humic substances:
1.Fulvic acids: the fraction of humus that is soluble in water under all pH
conditions. Their colour is commonly light yellow to yellow-brown.
2.Humic acids: the fraction of humus that is soluble in water, except for
conditions more acid than pH 2. Common colours are dark brown to black.
3.Humin: the fraction of humus that is not soluble in water at any pH and that
cannot be extracted with a strong base, such as sodium hydroxide (NaOH).
Commonly black in colour.
25. Functions of humus:
1. Improved fertilizer efficiency , Nutrients in organic matter are not readily
leached from the soil.
2. longlife N - for example, urea performs 60-80 days longer;
3. improved nutrient uptake, particularly of P and Ca;
4. stimulation of beneficial soil life;
5. provides magnified nutrition for reduced disease, insect and frost
impact;
6. salinity management - humates “buffer” plants from excess sodium;
7. organic humates are a catalyst for increasing soil C levels.
8. Supply plant-available phosphorus and plant-available sulfur when soil
humus is present (25% or more)
9. Furnish 30% to 70% of a soil’s cation exchange capacity. The higher a
soil’s cation exchange capacity, the greater its ability to hold onto
nutrients until needed by the plant and microbes.
10. Reduce Soil Erosion
11. Organic matter is a carbon (food) supply for beneficial soil microbes.
29. 1.Soil Biota
• The soil contains a vast array of life forms
ranging from submicroscopic (the viruses), to
earthworms, to large burrowing animals such
as gophers and ground squirrels. Microscopic
life forms in the soil are generally called
the "soil microflora" (though strictly speaking,
not all are plants in the true sense of the
word) and the larger animals are
called macrofauna
30. 2.Soil Microorganisms
• Soil microorganisms occur in huge numbers
and display an enormous diversity of forms
and functions. Major microbial groups in soil
are bacteria (including actinomycetes), fungi,
algae (including cyanobacteria) and protozoa.
31. 3.Nutrient Cycling by Soil Microbes
• Soil microbes exert much influence in
controlling the quantities and forms of various
chemical elements found in soil. Most notable
are the cycles for carbon, nitrogen, sulfur and
phosphorus, all of which are elements
important in soil fertility, and as we know
today, may be involved in global
environmental phenomena.
32. 4. Bioremediation
• Bioremediation may be defined as the controlled
use of microorganisms for the destruction of
chemical pollutants. A large number of processes
have been developed to handle various wastes
and for the cleanup of spilled organic materials.
At the heart of all of these processes lies the
premise that the metabolic activities of bacteria
or fungi can be used to degrade many of the
organic chemicals of commerce (solvents,
pesticides, hydrocarbon fuels, etc.).
33. Functions of Soil Micro organisms
S.no Function Microorganism Involved
1 Maintenance of soil structure Bioturbating invertebrates
and plant roots,
mycorrhizae and some
other micro-organisms
2 Regulation of soil hydrological processes Most bioturbating
invertebrates and plant
roots
3 Gas exchange and carbon sequestration
(accumulation in soil)
Mostly micro-organisms
and plant roots, some C
protected in large compact
biogenic invertebrate
aggregates
34. Functions of Soil Micro organisms
S.no Function Microorganism Involved
4 Soil detoxification Mostly micro-organisms
5 Nutrient cycling Mostly micro-organisms
and plant roots, some soil-
and litter-feeding
invertebrates
6 Decomposition of organic matter Various saprophytic and
litter-feeding invertebrates
(detritivores), fungi,
bacteria, actinomycetes
and other micro-organisms
35. Functions of Soil Micro organisms
S.no Function Microorganism Involved
7 Suppression of pests, parasites and diseases Plants, mycorrhizae and
other fungi, nematodes,
bacteria and various other
micro-organisms,
collembola, earthworms,
various predators
8 Sources of food and medicines Plant roots, various insects
(crickets, beetle larvae,
ants, termites),
earthworms, vertebrates,
micro-organisms and their
by-products
9 Symbiotic and asymbiotic relationships with
plants and their roots
Rhizobia, mycorrhizae,
actinomycetes,
diazotrophic bacteria and
various other rhizosphere
micro-organisms, ants
36. Functions of Soil Micro organisms
S.no Function Microorganism Involved
10. Plant growth control (positive and negative) Direct effects: plant roots,
rhizobia, mycorrhizae,
actinomycetes, pathogens,
phytoparasitic nematodes,
rhizophagous insects,
plant-growth promoting
rhizosphere micro-
organisms, biocontrol
agents Indirect effects:
most soil biota
40. Compost
• Compost is natural, inexpensive and good for the environment. By using
food scraps and garden vegetation as compost, you:
41.
42.
43.
44.
45.
46. Compost
• Compost use can result in a variety of environmental benefits. The
following are a few of the most important benefits
• 1. Compost enriches soils
• 2.Compost helps cleanup contiminated soils
• 3. Compost helps prevent pollution
• 4.Using compost offer economic benefits.
• 5. Compost contains macro and micronutrients often absent in synthetic fertilizers.
• 6. Compost releases nutrients slowly—over months or years, unlike synthetic
fertilizers Compost enriched soil retains fertilizers better. Less fertilizer runs off to
pollute waterways.
• 7. Compost buffers the soil, neutralizing both acid & alkaline soils, bringing pH
levels to the optimum range for nutrient availability to plants.
47.
48.
49.
50.
51.
52.
53.
54.
55. Compost binds soli particles
1. Compost helps sandy soil retain water and nutrients.
2. Compost loosens tightly bound particles in clay or silt soil so roots can spread,
water drain & air penetrate.
3. Compost alters soil structure, making it less likely to erode, and prevents soil
spattering on plants—spreading disease.
4. Compost can hold nutrients tight enough to prevent them from washing out, but
loosely enough so plants can take them up as needed.
5. Compost makes any soil easier to work.
56. Compost brings and feeds diverse life
in the soil
• Compost bacteria break down organics into plant available nutrients.
Some bacteria convert nitrogen from the air into a plant available nutrient.
• Compost enriched soil have lots of beneficial insects, worms and other
organisms that burrow through soil keeping it well aerated.
• Compost may suppress diseases and harmful pests that could overrun
poor, lifeless soil.
57. Compost increases soil’s ability to retain water & decreases
runoff.
1. Compost encourages healthy root systems, which decrease runoff
2. Compost can reduce or eliminate use of synthetic fertilizers
3. Compost can reduce chemical pesticides since it contains beneficial
microorganisms that may protect plants from diseases and pests.
4. Only a 5% increase in organic material quadruples soils water holding
capacity.
58. Compost and pH
• The composting process is relatively
insensitive to pH within the range commonly
found in mixtures of organic materials, largely
because of the broad spectrum of
microorganisms involved. The preferred pH is
in the range of 6.5-8.0. pH does become a
consideration with raw materials containing a
high percentage of nitrogen. A high pH, above
8.5, encourages the conversion of nitrogen
compounds to ammonia
59. Compost and time
• The time required to transform raw materials
into compost depends on many factors.
Proper moisture content, C:N ratio and
frequent aeration ensure the shortest
composting period. A well-managed
composting operation should produce quality
compost within four months
60. Co-composting
• Co-composting refers to composting that includes more than one organic
material. Some co-composting operations determine the portions of each
material by trial and error to obtain a compostable mixture. The trial and
error method could cause problems later. To obtain the best ingredients
for composting within the optimum time period without excessive odors,
follow a mixing procedure based on the physical and chemical
characteristics of the composting materials.
61. Compost enriches surface area
• Grinding, chipping, and shredding materials increases the surface area on
which the microorganism can feed. Smaller particles also produce a more
homogeneous compost mixture and improve pile insulation to help
maintain optimum temperatures .If the particles are too small, however,
they might prevent air from flowing freely through the pile.
62.
63. Compost and moisture content
• Microorganisms living in a compost pile need
an adequate amount of moisture to survive.
Water is the key element that helps transports
substances within the compost pile and makes
the nutrients in organic material accessible to
the microbes. Organic material contains some
moisture in varying amounts, but moisture
also might come in the form of rainfall or
intentional watering.
64. Compost provides oxygen flow
• Turning the pile, placing the pile on a series of pipes,
or including bulking agents such as wood chips and
shredded newspaper all help aerate the pile. Aerating
the pile allows decomposition to occur at a faster rate
than anaerobic conditions. Care must be taken,
however, not to provide too much oxygen, which can
dry out the pile and impede the composting process.
• A minimum oxygen concentration of 5% within the
pore spaces of the composting material is
recommended for a wellmanaged compost facility (air
contains about 21% oxygen).
65.
66. Compost and temperature
• Microorganisms require a certain temperature
range for optimal activity. Certain
temperatures promote rapid composting and
destroy pathogens and weed seeds. Microbial
activity can raise the temperature of the pile’s
core to at least 140° F. If the temperature does
not increase, anaerobic conditions (i.e.,
rotting) occur. Controlling the previous four
factors can bring about the proper
temperature.
67. Types of home-composters to buy or make
1. plastic bins with ventilation holes or slits
2. plastic bins without ventilation
3. metal drums with holes punched in the side
and the base removed
4. rotating drum units (tumblers)
5. enclosures made from timber (planks or
sleepers), bricks or chicken wire.
68. Tips for composting
1. Choose a shady spot in the garden to start
your compost heap or to position your
compost bin.
2. Add to your compost in layers of food
scraps, garden clippings and paper.
3. Keep your compost moist, but not wet, and
aerate it about once a week
4. Dig it into your garden or spread it on top as
mulch. Your compost should be ready when
it is dark and crumbly, after about four
months.
69. Composting is easy
1. Choose a shady spot in the garden to start your
compost heap or to position your compost bin.
There are many types of composting bins
available – some require mixing and some don’t
2. Add to your compost in layers of food scraps,
garden clippings and paper.
3. Keep your compost moist, but not wet and
aerate it about once a week.
4. When your compost is dark and crumbly
(about four months) dig it into your garden or
spread it on top as mulch.
70. What to put in your compost
1. Compost needs a ratio of three 'brown'
(carbon-rich) to approximately one ‘green’
(nitrogen-rich) amounts of material. You can
also add egg shells, tea bags and even dust
from the vacuum cleaner to your compost.
2. Brown: leaves, twigs, sawdust, shredded
paper.
3. Green: fruit and vegetable peelings, grass
clippings, soft prunings and leaves.
71. What u not add in compost
1. diseased plant material,
2. meat scraps and bones,
3. dairy products,
4. bread,
5. cake or
6. pet droppings.
72. Composting Process
• Composting converts Composting converts
organic waste such as leaves, kitchen scraps
and garden wastes…, into a valuable product
whi h h d i th hich, when used in the garden,
results in healthier plant growth healthier
plant growth when added to garden soil
73.
74.
75. How the Composting Process Works
1.Organisms involved in the composting
process
2.Variable components in the composting
process
3.Types o f ma terials (feedstocks) that can be
composted
4.Home composting systems
5.Uses of compost
76.
77. Compost conserve resources
1. Water
2. Energy and fuel
3. Composting could save your money
4. Compost reduces green house gases
5. Compost improves soil quality
84. 1.Burning of natural vegetation and crop
residues
• Burning destroys the litter layer and so diminishes the amount of organic matter returned to
the soil. The organisms that inhabit the surface soil and litter layer are also eliminated. For
future decomposition to take place, energy has to be invested first in rebuilding the microbial
community before plant nutrients can be released. Similarly, fallow lands and bush are
burned before cultivation. This provides a rapid supply of P to stimulate seed germination.
However, the associated loss of nutrients, organic matter and soil biological activity has
severe long-term consequences.
85. 2. Overgrazing
• Overgrazing destroys the most palatable and useful species in the plant
mixture and reduces the density of the plant cover, thereby increasing the
erosion hazard and reducing the nutritive value and the carrying capacity
of the land.
86. 3. Removal of crop residues
• Many farmers remove residues from the field for use as animal feed and
bedding or to make compost . Later, these residues return to contribute to
soil fertility as manures or composts. However, residues are sometimes
removed from the field and not returned. This removal of plant material
impoverishes the soil as it is no longer possible to recycle the plant
nutrients present in the residues
87. 4.Tillage Practices
• Tillage is one of the major practices that reduces the organic matter level in the
soil. Each time the soil is tilled, it is aerated. As the decomposition of organic
matter and the liberation of C are aerobic processes, the oxygen stimulates or
speeds up the action of soil microbes, which feed on organic matter.
• Tillage induced flush of decomposition of organic matter ( Source Glanz
1995)
Type of tillage Organic matter lost in 19 days ( kg/Hect)
Mouldboard plough + disc harrow (2x) 4300
Mouldboard plough 2230
Disc Plough 1840
Chiesel Plough 1720
Direct Seeding 860
88. 5.Drainage
• Decomposition of organic matter occurs more slowly in poorly aerated
soils, where oxygen is limiting or absent, compared with well-aerated soils.
For this reason, organic matter accumulates in wet soil environments. Soil
drainage is determined strongly by topography - soils in depressions at the
bottom of hills tend to remain wet for extended periods of time because
they receive water (and sediments) from upslope. Soils may also have a
layer in the subsoil that inhibits drainage, again exacerbating waterlogging
and reduction in organic matter decomposition
89. 6. Fertilizer and pesticide use
• Initially, the use of fertilizer and pesticides enhances crop development
and thus production of biomass (especially important on depleted soils).
However, the use of some fertilizers, especially N fertilizers, and pesticides
can boost micro-organism activity and thus decomposition of organic
matter. The chemicals provide the microorganisms with easy-to-use N
components. This is especially important where the C: N ratio of the soil
organic matter is high and thus decomposition is slowed by a lack of N.
90. Summerfallow
•
Summerfallowing accelerates the loss of organic
matter. Aeration of the soil associated with
tillage, and the increase in soil temperature and
moisture results in increased organic matter
decomposition. Since little In the way of residues
are added to the soil, a net loss of organic matter
occurs. Research has shown that as the frequency
of fallow increases, the amount of soil organic
matter decreases
94. 1. Compost
• Composting is a technology for recycling organic materials in order to
achieve enhanced agricultural production. Biological and chemical
processes accelerate the rate of decomposition and transform organic
materials into a more stable humus form for application to the soil.
Composting proceeds under controlled conditions in compost heaps and
pits.
Composting of manure and other materials will:
1. help stabilize nutrients
2. reduce the amount to spread (volume can be reduced by 30%-60%)
3. produce a better-smelling final product
95. 2.Cover Crops
1. They prevent erosion by anchoring soil and lessening the impact of raindrops.
2. They add plant material to the soil for organic matter replenishment.
3. Some, e.g. rye, bind excess nutrients in the soil and prevent leaching.
4. Some, especially leguminous species, e.g. hairy vetch, fix N in the soil for future use.
5. Most provide habitat for beneficial insects and other organisms.
6. They moderate soil temperatures and, hence, protect soil organisms.
96. 3.Green Manure
• Green manures are grown to add nutrients and organic
matter to the soil. Green manures are incorporated into the
soil while green or shortly after flowering.
97. 4. Crop Rotation
• Crop rotation is an integral part of the crop production system. The greatest
benefit to a good crop rotation is increased yields. A well-planned crop rotation
will help with insect and disease control and aid in maintaining or improving soil
structure and organic matter levels. Using a variety of crops can reduce weed
pressures, spread the workload, protect against soil erosion and reduce risk.
Legume crops in the rotation have become more valuable with the increased cost
of nitrogen. Research and experience have proven that a good crop rotation will
provide more consistent yields, build soil structure and increase profit potentia
100. 6.Zero Tillage
• Avoiding mechanical soil disturbance implies growing crops without mechanical
seedbed preparation or soil disturbance since the harvest of the previous crop.
The term zero tillage is used for this practice synonymously with terms such as no-
till farming, no tillage, direct drilling, and direct seeding.
101. 7. Agro forestry and Alley Cropping
• Agroforestry is a collective name for land-use systems where woody perennials
(trees, shrubs, palms, etc.) are integrated in the farming system (FAO, 1989). Alley
cropping is an agroforestry system in which crops are grown between rows of
planted woody shrubs or trees. These are pruned during the cropping season to
provide green manure and to minimize shading of crops (FAO, 1993).
102. 8. Balanced Ferilization
• Fertilizers should be applied in sufficient quantities and in balanced
proportions. The efficiency of fertilizer use will be high where the organic
matter content of the soil is also high. In very poor or depleted soils, crops
use fertilizer applications inefficiently. When soil organic matter levels are
restored, fertilizer can help maintain the revolving fund of nutrients in the
soil by increasing crop yields and, consequently, the amount of residues
returned to the soil.
103. 9. Improved Vegetative Stands
• In many places, low plant densities limit crop yields. Wide plant spacing is often
practised as “a way to return power to the soil” or “to give the soil some rest”, but
in reality it is an indicator that the soil is impoverished. Plant spacing is usually
determined by farmers in relation to soil fertility and available water or expected
rainfall (unless standard recommendations are enforced by extension). This means
that plants are often spaced widely on depleted soils in arid and semi-arid regions
with a view to ensuring an adequate provision of plant nutrients and water for all
plants.
104. 10. Protection from fire
• Burning affects organic matter recycling significantly. Fire destroys almost
all organic materials on the land surface except for tree trunks and large
branches. In addition, the surface soil is sterilized, loses part of its organic
matter, the population of soil microfauna and macrofauna is reduced, and
no ready-to-use organic matter is available for rapid restoration of the
populations.
105. 11. Crop residue management
1. Add soil organic matter, which improves the quality of the seedbed and
increases the water infiltration and retention capacity of the soil, buffers
the pH and facilitates the availability of nutrients;
2. sequester (store) C in the soil;
3. provide nutrients for soil biological activity and plant uptake;
4. capture the rainfall on the surface and thus increase infiltration and the
soil moisture content;
5. provide a cover to protect the soil from being eroded;
6. reduce evaporation and avoid desiccation from the soil surface.
106. 12. Integrated Pest Management
• As with balanced fertilization, proper pest and disease management
results in healthy crops. Healthy crops produce optimal biomass, which is
necessary for organic matter production in the soil. Diversified cropping
and mixed crop-livestock systems enhance biological control of pests and
diseases through species interactions. Through integrated production and
pest management farmers learn how to maintain a healthy environment
for their crops.
107. 13. Applying animal manure or other
carbon-rich wastes
• Any application of animal manure, slurry or other
carbon-rich wastes, such as coffee-berry pulp,
improves the organic matter content of the soil. In
some cases, it is better to allow a period of
decomposition before application to the field. Any
addition of carbon-rich compounds immobilizes
available N in the soil temporarily, as micro-organisms
need both C and N for their growth and development.
Animal manure is usually rich in N, so N immobilization
is minimal. Where straw makes up part of the manure,
a decomposition period avoids N immobilization in the
field.
108. 14.Mulch or permanent soil cover
• One way to improve the condition of the soil is to mulch the area requiring
amelioration. Mulches are materials placed on the soil surface to protect it
against raindrop impact and erosion, and to enhance its fertility (FAO,
1995). Crop residue mulching is a system of maintaining a protective cover
of vegetative residues such as straw, maize stalks, palm fronds and stubble
on the soil surface
109. 15. REDUCED SOIL EROSION AND
IMPROVED WATER QUALITY
• When the soil is protected with mulch, more water infiltrates into the soil
rather than running off the surface. This causes streams to be fed more by
subsurface flow rather than by surface runoff. The consequence is that the
surface water is cleaner and resembles groundwater more closely
compared with areas where erosion and runoff predominate. Greater
infiltration should reduce flooding by increased water storage in soil and
slow release to streams. Increased infiltration also improves groundwater
recharge, thus increasing well supplies.
110. 16.Reduced water logging
• However, in case of waterlogging, organic matter plays also an important
role. The bioturbating activity of the macrofauna leaves various so-called
conducting macropores in the soil, which are responsible for the drainage
of water to deeper soil layers.
111. 17. INCREASED BIODIVERSITY
• Conventional agriculture tends to reduce
aboveground and belowground diversity.
Thus, it brings about significant changes in the
vegetation structure, cover and landscape.
The change in vegetal cover during the
conversion of forest and pastures to cropping
affects plants, animals and micro-organisms
112. 18. Manures
• Livestock manure is an excellent source of organic matter for the soil.
Applying manure to the soil will provide other benefits, such as a greater
diversity and activity of organisms and better soil structure.
113. 19.Sanitation measures
• Sanitation measures can be used to help prevent the introduction of pests onto
the farm, to prevent the movement of pests within the farm, and to remove
overwintering or breeding sites for pests on the farm.
• Start with pest-free plants; inspect plants brought onto the farm to prevent the
introduction of pests.
• Removal or incorporation of crop residue can eliminate overwintering sites for
some pests.
• Infested plants should be removed and composted, buried, or otherwise destroyed
as soon as possible.
• .
114. 19.Sanitation measures
Removal of weeds and natural vegetation bordering crops may eliminate alternate
hosts for some insect pests. Bear in mind that these areas may also harbor natural
enemies; therefore, the grower must carefully assess the potential threat from
pest insects in these areas before mowing or removing any plants.
When working in an infested area, clean equipment and clothes before going to
another area of the farm. Pests such as whiteflies and spider mites can be carried
on workers' clothes and spread to new areas.
115. 20.Liming
The main purpose of liming is to raise soil pH
and supply calcium and sometimes
magnesium for plant growth. Other benefits
from liming acid soils include increased biotic
activity, enhanced mineralization of nutrients
from soil organic matter, improved soil
structure, decreased potential for aluminum
toxicity, and increased availability of other
nutrients, especially phosphorus.
