Soil Management in San Diego-

Urban Composting

Building Better Soils

Healthy Soils Support

Healthy Plants

Building Better Soils

Characteristics of “Healthy Soils”

• Granular Structure• Organic matter suitable for plant

palette• Nutrient and water reservoirs are

sufficient to meet plant needs• Friable, good tilth

Building Better Soils

“Unhealthy Soils”• Compacted, poor structure• Heavy salt load• Insufficient organic matter present

for good plant growth, increased water holding capacity and to support soil life

• Plants subject to increased pathogen and pest pressure

Building Better Soils

Building Better Soils

Challenges of San Diego Soils

• High Salts• Low Organic Matter• Variable pH• Sporadic Rainfall• Salty Water• Human Activity

Building Better Soils

Chemical Characteristics• pH• Salinity• Nutrients

Building Better Soils

Soil & Water ChemistryTotal Salts in the Soil/Water Solution

Beneficial– Potassium, Calcium , Magnesium– Sulfates, Nitrates

Damaging– Sodium– Chloride– Boron in excess

Building Better Soils

Soil pHHydrogen Ions in the Soil Solution

Building Better Soils

Chemical Characteristics• pH• Salinity• Nutrients

Building Better Soils

Physical Characteristics• Texture

– Percent of Sand, Silt and Clay– Percent of Organic Matter

• Structure– Arrangement of Particles

• Compaction• Drainage

Building Better Soils

Soil Texture

Building Better Soils

Building Better Soils

Importance of Soil StructureMicro-Aggregates

– clay microstructures, silt-size microaggregates, particulate organic matter, plant and fungus debris, and mycorrhizal fungus hypha

– Relatively stable – Building blocks for macro-aggregates

Building Better Soils

Importance of Soil StructureMacro-Aggregates• Bound by fungi hyphae, root fibers, and

polysaccharides • Reduce bulk density of the soil • Are less stable than micro-aggregates,

easily subject to compaction

Building Better Soils

Importance of Soil StructureMacro-aggregates provide macro-pores

– Drainage– Ability to leach– Air space– Reduces water molds and root rot

Building Better Soils

Building Better Soils

Use of Organics in Agriculture

• Compost• Mulch• Compost Tea

Building Better Soils

Organic Mulch Reduces Soil Compaction

• Using mulch helps reduce compaction. It acts like a sponge to absorb weight and water

• Shatters rain drops • Supplies food for microbes, which

encourages micro and macro aggregation

Conservation & Source Reduction

• The first and most important step!

• Saves the most money, reduces infrastructure costs, reduces demand for energy and resources.

Resource or Waste

What do we do with what's left over?

Bottles, Cans, and Paper

Transfer

Broker

Recycling Facility

End User

Waste

Transfer

Landfill

Organics

El Corazon Compost Facility

Back to Local Soils

Collection

Zero Waste OpportunityProducts and Services

El Corazon Method

Challenges and Barriers

Grinding for Size Reduction

Pathogen Reduction ProcessThe Title 14 “Process to Further

Reduce Pathogens” is a natural activity that uses the heat generated by microbial activity to kill both plant and human pathogens.– 131° F for at least 15 days– Turn at least 5 times during this process– Water and nitrogen must be present in

sufficient quantities

Using PRFP to Mitigate Pesticides, Weed Seeds and

Insect Larvae

• Many pesticide residues, weed seeds and insects are controlled during the same time frame

• More resistant pesticides residues may require longer composting periods

Screening

Building Better Soils

Quality Control

• Laboratory Analysis– Nutrients– pH– Metals– Pathogens

Building Better Soils

Quality Control

• On-Site Analysis– pH– Moisture– Oxygen– Solvita– Mineral Nitrogen– Microscope

Building Better Soils

Soil Sampling• Composite Samples• At least 2 quarts• Use a soil tube

Community Involvement

Building Better Soils

Follow us on Facebook!

www.AgriServiceInc.com

Thank You!