Why should we all care about barren lands?

1. They are expanding in arid and semi-arid regions
2. Little or no forage production (no agricultural uses)
3. Low-quality habitat for wildlife
4. Poor aesthetics
5. Likely hot spots of dust production

Soil Aerosols

Malm et al. (1994) Journal of Geophysical Research

We can’t not talk about water erosion

Belnap et al. (2011) Ecohydrology

Arizona Department of Public Safety

Field et al. (2012) The ecology of dust. Frontiers in Ecology Environment

New solutions are needed!

Currently available BMPs for barren lands

q    Mechanical treatment (e.g., berms)

Underlying soil structural instability is not fixed

 Currently available BMPs for barren lands

q    Synthetic polymers (e.g., Soil Sement, Gorilla-Snot®)

Not guaranteed beyond 3 years;

Do not promote plant growth

Soil Sement applied next to Interstate-10 between Tucson and Phoenix, AZ

 Currently available BMPs for barren lands

q    Critical area planting

Limited success with “plant-centric” practices in arid regions,

likely because soil health is not improved

Motivating Research Question for the Remainder fo My Talk

• Can we improve the long-term success of stabilizing and

revegetating barren arid soils by explicitly considering

organic matter and the soil microbiome?

• Are organic matter and soil biology missing ingredients for

“jump starting” barren systems in the Desert Southwest?

Ground zero for needing soil "probiotics?"

Water-Stable Soil Aggregate

Macroaggregate separation by wet sieving                                                               

Barren lands are aggregate-poor

Blankinship et al. (In prep)

Extracellular Polymeric Substances (EPS)

  Enmeshment by Fungi 

Obligatory Box & Arrow Diagram

Obligatory Box & Arrow Diagram

Benefits of Using Organic Amendments in Dust Mitigation Projects 

q  Promotes soil structure directly

q  Improves microclimate by covering soil and slowing H2O

q  Carbon source for carbon-starved soil microbes

q  Nutrient source for potentially nutrient-starved plants

Wood Mulch

Compost + Mulch

Compost + Biochar

Augmenting the Soil Microbiome Directly

• Managing existing soil microbes
• Boosting with probiotics

Managing Existing Soil Microbes for Water-Stable Aggregate Formation

Chloroform Sterilization

Boosting the Soil Microbiome with Probiotics

• Inoculation with commercially available products

Boosting the Soil Microbiome with Probiotics

Inoculation with commercially available products

• Which ones work best for “bioengineering” soil aggregates?
• Which ones promote plant growth in barren ecosystems?
• Which products are economically viable?
• How much/often to apply?
• What time of year to apply?

Boosting the Soil Microbiome with Probiotics

• Inoculation with commercially available products
• Bio-crust “farming"