Arid Land Research Fund

Improving the effectiveness of rehabilitation techniques at multiple scales!

Project #2

Assessing seed coatings for successful Indian ricegrass restoration.

Research Objective

  • Determine seed coating efficacy for germination & establishment
    • Four seed coatings
    • Irrigated (simulated rainfall) and non-irrigated treatments
    • Determine role of soil temperature at two depths, (5 cm and 10 cm) on success of both irrigated and non-irrigated plots

Relevance

  • Approximately 40% of the world’s rangelands are desertified. To combat desertification and improve understanding of how to restore very dry lands, use of seed coatings is being explored
  • Indian ricegrass, an important perennial grass in the US Southwest, has been significantly reduced since settlement by over-grazing. It is proved difficult to reestablish – seed-coatings hold promise to be the solution

Restoration Challenges

  • Arid lands with very little topsoil and precipitation are very challenging to restore
    • Low germination and establishment of native species
    • High failure rate
    • Increased erosion

Vast arid desert landscape with a large horizon.

Desert landscape with weeds.

Seed Coatings

Coatings help seedlings break through crusts, delay or hasten germination, improve germination and establishment.

Stages of seedlings growth.

A large group of planted seeds.

Several trenches of seedlings.

Study Area

  • Both sites south of Tonopah, NV
  • Potential Study Site #1 is a better fit than Alternative Study Site #2
    • Alternative Study Site #2 has steep slopes, limited access and is not representative of larger area
  • Very low precipitation
  • Historically dominated by Indian ricegrass

A map showing several potential study sites.

Potential Study Site #1

(2 Separate Locations)

The west side of the first potential study site.

West side of Highway 95 (preferred)

  • Loamy 5-8 ecological site
  • Representative of majority of acres in the area
  • Has likely experienced topsoil loss
The east side of the first potential study site

East side of Highway 95 (not preferred)

  • Sandy 5-8 ecological site
  • Represents only a small number of acres
  • Much more influenced by current off-road recreation use

Plot Design

Plot design with a split plot for irrigated and non-irrigated treatments. Each seed treatment will be replicated six times.

A visualization of a plot design and an inner look at the replicates that are contained within it.

Possible Benefits

  • Best case scenario
    • Use of seed treatments greatly increases seedling germination and establishment on the non-irrigated sites leading to breakthroughs in arid last restoration and reclamation in arid environments (5-8 inches of precipitation annually).
  • Possible scenario
    • Findings document that irrigation is only necessary for a short period of time to boost seedling germination and establishment with treated seeds.
  • Possible scenario
    • Substantial differences are seen between seed treatments and one treatment outperforms the rest.
  • Poor outcome scenario
    • Irrigation is shown to be critical in all stages of life for germination, establishment and survival of Indian ricegrass.
  • Worst case scenario
    • Nothing works.

Budget & Schedule

Years 1-5

  1. $56,000
  2. $47,000
  3. $47,000
  4. $22,000
  5. $22,000

Total: $194,000

To make a donation to the fund

Please contact Christina Sarman

 

Who do I contact for more information?

Tamzen K. Stringham, Endowed Professor of Rangeland Science
Tamzen