Compost and mulch provide many direct and indirect benefits when utilized in landscaping and as a component of systems and treatments designed for carbon sequestration, erosion control, fire remediation, stormwater management, and other uses. The following are some of the benefits.

Agriculture

  • Improves plant growth and health
  • Provides plant nutrients in a stable organic form
  • Increases plant rooting depth
  • Improves physical, biological, and chemical soil properties
  • Reduces erosion
  • Conserves water
  • Mulch reduces weed germination and moderates soil temperature

Air

  • Reduces greenhouse gas (GHG) emissions; sequesters carbon
  • Reduces particulate (PM10 and PM 2.5) dust emissions
  • Compost blankets reduce landfill methane emissions

Climate Change Adaptation

  • Compost and mulch help California adapt to climate change by sequestering carbon, reducing greenhouse gas emissions, conserving water, reducing erosion, reducing flooding and mudslides; reducing energy use; a component of systems that provide natural flood control
  • Systems/treatments that use compost and mulch (e.g., green roofs) insulate buildings, provide acoustic insulation, provide shade, reduce ambient air and building temperatures

Economics

  • Saves money: specific compost and mulch treatments are more cost effective than other systems and treatments that do not use compost and mulch
  • Reduces water and energy use/costs
  • Reduces use/costs of synthetic fertilizers and pesticides
  • Reduces water infrastructure costs

Energy

Soil

  • Intercepts and absorbs falling rain, reducing runoff and associated sediment losses
  • Provides an environment where seeds can germinate and grow to hold soils in place
  • Improves physical, biological, and chemical properties of soils
  • Increases soil organic matter (SOM), aggregate stability, hydraulic conductivity, infiltration rate, water holding capacity, and plant available water
  • Decreases bulk density
  • Reduces erosion
  • Feeds the soil food web, the bacteria, fungi, and other organisms that transform and release nutrients from organic matter

Remediation and Restoration

  • Compost and mulch used to restore riparian zones and watersheds
  • Used to remediate land post-fire
  • Sequesters and breaks down contaminants in soil and water, including chlorinated and non-chlorinated hydrocarbons, wood preservatives, solvents, heavy metals, pesticides, and petroleum products

Sustainable Landscaping

  • Improves plant growth and health
  • Improves aesthetics through attractive organic mulches and by promoting healthy plants
  • Reduces use of synthetic fertilizers and pesticides
  • Conserves water
  • Provides habitat

Water

  • Compost and mulch are important components in stormwater management systems/treatments, including green infrastructure and low impact design (LID)
  • Conserves water and replenishes groundwater
  • Improves water quality by adsorbing contaminants and capturing sediment (see Remediation and Restoration)
  • Reduces rain impact, improves water infiltration and storage, and reduces runoff volume and velocity; reduces runoff of total suspended solids