Lecture 34
Download
1 / 14

Lecture 34 - PowerPoint PPT Presentation


  • 73 Views
  • Uploaded on
  • Presentation posted in: General

Lecture 34 Leaching requirements - irrigation and drainage water quality recycling of drainage water for irrigation. Extensive areas of land in the arid and semi arid regions of India have gone out of cultivation due to the rise of water table and accumulation of salt.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Lecture 34

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Lecture 34

Leaching requirements - irrigation and drainage water quality recycling of drainage water for irrigation


  • Extensive areas of land in the arid and semi arid regions of India have gone out of cultivation due to the rise of water table and accumulation of salt.

  • Excessive irrigation and poor water management are the chief causes of water logging and salt build-up.

  • An accumulation of salts in soils leads to unfavorable soil-water- air relationships and decreases crop production.

  • Gradually, the land goes out of cultivation, unless remedial measures are under taken.


LEACHING

Leaching is the process of removal of soluble material by the passage of water through soil.

LEACHING REQUIREMENT

It is the minimum amount of irrigation water that must be drained through the crop root zone to control the soil salinity at the given specific level.


  • LEACHING METHODS

  • By ponding an appreciable depth of water on the soil surface by means of dikes or ridges

  • Rectangular checks and level borders are used when the land is flat.

  • Contour checks can be used when the land slope is considerable.

  • The effectiveness of leaching by furrows is limited.

  • Sprinkling is an effective method for leaching, especially when soils are cracked or are highly permeable.

  • Intermittent ponding is superior to continuous ponding for effective leaching.


  • The efficiency of leaching depends on

  • The amount of water applied,

  • Uniformity of water distribution, and

  • The adequacy of drainage


For surface irrigation method including sprinkler

Where,

ECw = Electrical conductivity of the irrigation water, dS/m

ECe = Electrical conductivity of the soil saturation extract for a given crop proportional to the tolerable degree of yield loss


For drip irrigation method

Where,

ECw = Electrical conductivity of the irrigation water, dS/m

Max.ECe =MaximumtolerableElectrical conductivity of the soil saturation extract for a given crop


  • Salinity management techniques

  • Frequent irrigation

  • Crop selection

  • Preplanting irrigation

  • Higher Seed rate

  • Blending with good quality irrigation water

  • Irrigation rotation with good and poor water

  • Land grading

  • Deep ploughing and subsoiling

  • Drainage

  • Rain water management


  • Drainage water use

  • Used for irrigation by mixing with canal water

  • Dispose off the water by gravity/ by lift irrigation

  • Evaporation tanks

  • Bio-drainage

  • Brackish water fish culture


HE WHO PROVIDES WATER DESERVES TWO NOBEL PRIZES

ONE FOR PEACE AND THE OTHER FOR SCIENCE

-John F. Kennedy-


LET US WORK TOGETHER TO MANAGE AVAILABLE WATER


Thank you...

Water is precious… conserve it…


ad
  • Login