SOIL FERTILITY IMPROVEMENTDepartment of Agriculture

In – Service Training 30th May 2012

Valentine Michelo

CONTENT

1. TYPICAL SOIL PROFILE

2. WHAT IS SOIL FERTILITY?

3. QUALITIES OF A GOOD SOIL

4. SOIL DEGRADATION

5. FACTORS LIMITING GROWTH IN PLANTS

6. METHODS OF IMPROVING SOIL FERTILITY

Typical Soil Profile

A Horizon (Top Soil)

B Horizon (Sub Soil)

C Horizon (Parent Material)

Bed Rock

25 cm

75 cm

100 cm

Litter

What is Soil Fertility?Capacity of soils to supply essential plant

nutrients (plant food)in amounts and forms that a plant can easily take them up.

A physically, chemically and biologically good soil medium is required for easy nutrient uptake by plants from the soil.

Qualities of a Fertile Soil

Deep Enough for easy Root Penetration.

Good structure for aeration, drainage.

Favourable soil reaction (pH). For most crops a pH range of 5.5 – 6.5 is acceptable).

Qualities of a Fertile Soil

Have good supply of available & reserve plant nutrients

Able to store Soluble Nutrients

Contain Sufficient Organic Matter(SOM)

What is meant by Soil Degradation?

A situation where productivity of the soil declines.

Results of Soil Degradation

Causes of Soil Degradation..

Permanent Flooding

Prolonged Heat (“Kills” the soil)

Physical disturbance

Causes of Soil Degradation(Cont..)

Leaching

Nutrient removal through Harvests

Soil Erosion

HEALTHY SOILS

Fertile soils contain small living Plants & Animals ( Bacteria, Fungi, Worms etc).

Earth worms

Factors Limiting Growth in Plants

1• pH (Soil Reaction).

2• Light

3• Atmosphere(Oxygen, Carbon

dioxide & Humidity)

Factors Limiting Growth in Plants(Contd..)

4• Temperature

5• Nutrients/”Plant Food”

Methods of Improving Soil Fertility

1. Agro forestry

2. Biological Nitrogen Fixation(BNF)

3. Use of Artificial (Inorganic) Fertilizers

Drawbacks of Artificial Fertilizers Excess easily leached out of the soilRequire Adequate knowhow:

What to apply, Amounts to apply, How to apply, Timing of application.

Expensive & May Not be AvailableContain No Organic Matter

Methods of Improving Soil Fertility(Contd..)

4. Use of Organic Fertilizers/Manures(Plant & Animal Material)

Organic Fertilizers/Manures

1

•Farm Yard Manure(FYM)

2

•Green Manures/Improved Fallows

3

•Crop Residues

4

•Mulching

CONCLUSIONSUse of Soil Fertility Improvement techniques

will NOT IN ITSELF raise yields. Other Practices also need to be applied:

Improved SeedGood Farm PreparationRecommended SpacingEarly PlantingPest & Weed ControlAvailability of Adequate Rains & Water for

Irrigation

The End. Thank You..