YEAR 2 SEM 1

·       Introduction.

Ø  Definitions.

Ø  Importance of irrigations.

Ø  Basic plant’s needs.

Ø  Conditions requiring irrigation.

Ø  An inventory of irrigation schemes in Kenya

·       Planning for a small scale farm irrigation system

Ø   Identification of potential area.

Ø   Objectives.

Ø   Survey and data collection etc.

 

·       Plaint , soil water  relationship

Ø  Need for irrigation

Ø  Terminology used in soil moisture e.g.available moisture, Unavailable moisture and Effective root zone.

Ø  Permanent wilting point

Ø  Readily available moisture

Ø  Readily available factor and influence of different soil type.

 

·       Term used in crop water requirements:

Ø  Evaporation

Ø  Transpiration

Ø  Potential evapotranspiration

Ø  Actual evapotranspiration

Ø  Reference evaporation

·       Estimating irrigation water:

Ø  Metrological factors

Ø  Crop factors

Ø  Effective rainfall

Ø  Ground water contribution

Ø  Soil storage

Ø  Leaching fraction

Ø  Irrigation efficiency

 

·       Irrigation requirements:

Ø  Use of tables and charts

Ø  Net irrigation requirement

Ø  Gross irrigation requirement

Ø  Irrigation intervals

 

·       Measurement of irrigation water:

Ø  Reasons for measuring water

Ø  Methods of measuring irrigation water by:

§   Wells

§   Metro gates

§   Phrasal

 

·       Irrigation   pumps

Irrigation principles of pumps:

Ø  Piston pumps

Ø  Diaphragm types

Ø  Sub-mersible type

Ø  Hydram type

Ø  Rotary pump

 

·       Selection requirement of the pumps:

Ø  Power  requirements

Ø  Pump efficiency

Ø  Area to be irrigated

Ø  Quality of water

 

·       Water application factors:

Ø  Type of soil

Ø  Topography

Ø  Quality   and quantity of water

Ø  Crop type

Ø  Farming practices

Ø  The government policy

Ø  Economics

 

·       Irrigation methods:

Ø  Border irrigation

Ø  Check basins

Ø  Furrow irrigation

Ø  Sprinkler irrigation

Ø  Drip irrigation

 

·       Irrigation problems:

Ø  Salt problems

Ø  Alkalinity

Ø  Salinity

Ø  Siltation and water table

 

·       drainage

 

Reasons for drainage

Ø  Control of salts

Ø  High water table

Ø  Unfavorable slopes

 

Drainage systems

Ø  Open drainage.

Ø  Covered drainage.

Ø  Sub-surface drainage.

 

Reference books

1.     Irrigation principles and practices by Israelson and Hanson.

2.     Irrigation Theory and practice by A.M Michael.

3.     Elementary soil and water Engineering 3^rd Edition by G.O Scwab and R..K. Frevert

Learning outcomes

       i.          Definition of irrigation.

     ii.          Water sources for plant.

   iii.          Basic water needs for plants.

   iv.          Describe plant, soil and water relationship.

     v.          State factors for selection of pumps, channels and pipes.

   vi.          Describe different irrigation methods and techniques.

 vii.          State factors to consider in planning a small scale farm irrigation system.

viii.          State different types of drainage systems.

   ix.          Explain a given technique of land reclamation.