T17+Slides

T17+Slides - 4 Must provide adequate drainage Leach salts...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Saline and Sodic Soils Saline Soils Saline soils – too much salt! Electrical conductivity > 4 dS/m Major components of soluble salts Cations: calcium, magnesium, potassium Anions: chloride, sulfate, bicarbonate Sodic Soils Sodic soils – too much sodium! Exchangeable sodium percentage: ESP >15% ESP = Ca 2+ + Mg 2+ + K + + Na + Na + ×100 Na-feldspar + H 2 CO 3 = Na + + HCO 3 - + kaolinite Origin of Salts Chemical Weathering Fossil Salts Irrigation Water Groundwater Eolian Inputs Precipitation Inputs
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 ET > Precipitation No leaching Restricted Drainage Improper Irrigation Salts lower the osmotic potential Direct toxicity Sodium, lithium, chloride, boron Trace element deficiencies ( pH) Sodium destroys soil structure Salt lowers ψ o Ψ o <-15 bars Sodium destroys soil structure Calcium promotes soil structure Reclamation of Saline Soils Must provide adequate drainage Leach salts Dispose of drainage waters, if necessary Reclamation of Sodic Soils Addition of calcium amendment (CaSO
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 4 ) Must provide adequate drainage Leach salts Dispose of drainage waters, if necessary 3 Furrow Irrigation Sprinkler and Drip Irrigation Infrared photograph showing salt effects – red colors indicate healthy vegetation Drain tiles for leaching and removal of salts Owens Dry Lake Bed Soils contains much salt and shallow anoxic groundwater Drainage and leaching of salts allows growth of native, salt tolerant vegetation 4 San Luis Drain was initially discharged into the Kesterson Wildlife Refuge Potentially toxic trace elements (Se, As, B, Mo) concentrate in water, salts, and food web (algae, brine shrimp) San Joaquin River Irrigation: <0.7 dS/m Non-irrigation: <1 dS/m Possible San Joaquin Valley Solutions Export salts in San Joaquin River Extend the San Luis Drain On-farm evaporation basins Water conservation and drainage reuse Take land out of production...
View Full Document

This note was uploaded on 01/27/2011 for the course SSO 10 taught by Professor Randydahlgren during the Fall '10 term at UC Davis.

Page1 / 4

T17+Slides - 4 Must provide adequate drainage Leach salts...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online