Welcome to the Lower Colorado River Multi-Species Conservation Program
Lower Colorado River Multi-Species Conservation Program Balancing Resource Use and Conservation

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Vegetation and Habitat

      Research and Monitoring - Soil Studies

Testing the soil amendment in the laboratory in 2010 showed that a mix of 5% amendment in sand (right) is significantly better had holding moisture than pure sand (left) - Denver Technical Science CenterTesting of the soil amendment will continue at the Beal Riparian and Marsh Restoration where soils are extremely sandy - Reclamation - AshleeRudolphReclamation employees add water the troughs to test the water holding capacity of Lassenite Pozzolan at Reclamation's Denver Technical Science Center in April 2010. - Denver Technical Science Center

Soil Studies

In 2006, Reclamation's Denver Technical Service Center conducted a literature and product search of various soil amendments that would possibly improve habitat restoration capabilities at sites containing sandy soils. This study tests the most promising soil amendment that emerged from that work, Lassenite Pozzolan. Lassenite is mined in northern Nevada and has been marketed for use in golf course construction, largely in the deserts of Saudi Arabia. Testing by the distributor has shown it increases the moisture holding capacity of sand and, unlike organic materials, does not breakdown chemically. However, Lassenite has not been tested at lower application rates, at deeper rooting depths, or as a means to facilitate moving irrigation water across large expanses of sandy soils.

In 2009, a study was funded to examine the use of Lassenite to improve sandy soil conditions at some restoration sites. Through a series of experiments under laboratory conditions, Lassenite will be tested to determine its potential to:

  1. Increase the water retention of sand,
  2. Decrease travel time of irrigation water across and through sand,
  3. Persist within the root zone of plants,
  4. Increase the wicking of moisture to the surface of sandy soils in specific locations within restoration sites.

If results are positive in these areas, Lassenite has the potential for lowering irrigation frequencies and amounts and therefore pumping costs. The addition of Lassenite to soils could then be included in site preparation plans.

For additional information on this project, please refer to Work Task C42: Experiments and Demonstration of Soil Amendments for Use in Restoration Sites (PDF). Find Technical Reports for this Work Task here.

Updated December 30, 2015