Ecological Landscaping Association's 2013 Conference & Eco-Marketplace February 27, 2013 Geoff Kuter, Ph.D. Agresource Inc. www.agresourceinc.com
Since 1984, providing organic waste management services to municipal and corporate clients. Land application of biosolids, wastewater and water treatment residuals from municipal and industrial sources. Operation of regional composting facility in Ipswich MA. Compost marketing services for municipal and private facilities. Agresource Inc. 100 Main St. Amesbury MA 01913 www.agresourceinc.com
Compost Marketing Services Facilities in: New England, New York and New Jersey distributed into PA, MD and VA. Composts from: Municipal Biosolids, Leaf and Yard Wastes, Food Wastes and Food Processing Residuals, and Manures
Compost The product generated from recycling organic residues (wastes) into usable and valuable products. Compost is a soil amendment with various uses and numerous benefits.
Composting Facilities Agresource Inc. 100 Main St. Amesbury MA 01913
Composting Process Temperatures favoring the growth of thermophilic microbes (35 to 60 C or 105 to 160 F). Under aerobic (the presence of oxygen) conditions. Controlled process.
Compost Temperatures Temperatures adequate for sufficient time to kill pathogens and destroy weed seeds (55 C for 3 days). Not too high as to slow microbial growth or generate fires.
Benefits of Composting Recycle wastes in to a more usable product: COMPOST Carbon in residuals ( wastes ) is returned to the soil Landfill disposal generates methane a powerful greenhouse gas Incineration generates CO2; carbon not conserved
What is Compost? Compost is a soil amendment that: Provides organic matter Supplies nutrients Stimulates microbial activity Compost is not: Top soil or loam Fertilizer Pesticide or a biological control agent
The Benefits of Using Compost Improve soil physical properties by adding Organic Matter Increase water holding capacity Improve physical structure (soil pore space) Lower soil bulk density Reduce water use for irrigation Improve water infiltration into soil surface Reduce erosion
The Benefits of Using Compost Add nutrients and improve nutrient holding capacity Increase Cation Exchange capacity Provides nutrients in organic or slow release form Reduce use of fertilizer Improve nutrient availability Decrease loss of nutrients due to leaching Improve plant growth and survival
The Benefits of Using Compost Environmental benefits associated with sustainable landscape practices Wastes are recycled Carbon is returned to soil Metals such as lead are made less available Organic contaminants are degraded by microbial activity Soil compaction reduced & water infiltration improved Reduction in green house gas emissions Contaminated soils are made safer Less storm water run-off
Compost Use Recommendations For many landscape projects 20 to 25 % compost (by volume) added to the existing soil will provide multiple benefits Adding 1 to 2 inches of compost and tilling into the top 4 to 6 inches of soil before planting or mixing one part compost to 3 to 4 parts of soil.
Successful Use of Compost 1. Understand design goals and project objectives 2. Knowledge of existing soil conditions and site environment 3. Familiarity with composts that are available
Compost Quality Not all composts are the same Moisture content Texture and particle size Organic matter content ph, soluble salts, and nutrients
Compost Quality Product characteristics depend upon: Feedstocks: Biosolids vs. Food Wastes vs. Manures Bulking Agents: Wood chips vs. Sawdust vs. Leaves Type of processing: Screened vs. Unscreened Age: Active vs. Aged
Types of Compost (by type of feed stocks) Leaf and Yard Compost Biosolids Compost Manure Compost Food Waste Compost Wood Ash Paper fiber (SPF)
Compost Properties Organic Matter: Undecomposed residuals, active and dead microbes (Biomass) and the products of decomposition (Humic matter) Nutrients: macro (NPK) and and micro nutrients Ash and grit
Organic Matter and Organic Carbon Organic matter measured as % Volatile Solids; Material that is oxidized when the compost is burned. % Organic matter + % Ash = 100 % Organic Carbon is % of the volatile solids that is in the form of Carbon (C). Organic Carbon is 54% of the Organic Matter Organic Carbon is used to calculate C:N ratio
Raising Soil Organic Matter Percentage to Raise OM Compost Inclusion Rate by 1% need 8% by volume 2% 15% 3% 22% 4% 27% 5% 32% 6% 37% All rates based on addition of AGRESOIL COMPOST to typical soil weighing 2,600 lbs/cu. yd.
Adding Compost to Reach Specified SOM Levels Rate of compost addition can be calculated from % OM and Bulk Density (Compost 0.56 T/CY; 60% TS and 45% OM) 16.0% 14.0% % OM of soil mix with compost 12.0% 10.0% 8.0% 6.0% 4.0% 1% OM 2% OM 3% OM 4% OM 5% OM 2.0% 0.0% 0% 20% 40% 60% percent compost in mix
As % Soil Organic Matter Increases: Plant Available Nutrients Increase Level of Nutrients Depend on Type of Compost (e.g. Biosolids vs. Leaf) At High Levels of SOM Addition of Compost May Result in Excessive Nutrients
Lawn Comparison
Compost Uses Examples of product use: Establishing lawns and turf Root zone mix for sports fields Top dressing lawns and sports fields Planting beds Tree and shrub planting mix Wetland construction and remediation Green roof media Infiltration basins for storm water management Root zone mix for constructing golf greens Potting media component
Choosing The Right Compost for the Right Use Finer texture for topdressing (<1/2 inch acceptable; <3/8 inch preferable) Coarser texture for mulch (< 1 inch) ph, soluble salt: highly dependent on plant choice and application rates Aged for potting mixes Avoid compost with high silt/clay for sports field mixes Low nitrogen and phosphorus near water resources
General Guidance A soil analysis should be completed by a reputable laboratory to determine any nutritional requirements, ph, and organic matter adjustments that may be necessary. Once these are determined, the soil can be appropriately amended to a range suitable for the particular plants being established. The nutrients contained in compost should be considered when applying fertilization. They will typically offset nutrient requirements, thereby reducing application rates.
Lawns and Turf
Sports Field Construction Agresource Inc. 100 Main St. Amesbury MA 01913
Optimizing Organic Content in Soil Specifications 3% to 10% often specified 3% unnecessarily low for lawn areas 10% too high for lawns 5% to 8% for lawns, reduces risk, and saves water 4% to 6% for sports fields Balance organic content with infiltration rate
All Composts are Not the Same Comparison of Different Composts on Infiltration Rate All Mixes: 80% Sand: 20% Compost Silt Clay Total Infiltration Rate Compost A 3.33 % 1.06 % 4.39 % 16 In/Hr Compost B 6.07 % 0.69 % 6.76 % 12 In/Hr Compost C 5.43 % 2.03 % 7.46 % 4.6 In/Hr
Topdressing Agresource Inc. 100 Main St. Amesbury MA 01913
Town of Upton MA: Topdressing For Sports Fields Maintenance Annual topdressing Core aeration and over seeding. Reduced use of fertilizers, improved water holding, and faster seed germination.
University Research Programs DETERMINING THE IMPORTANCE OF LEAF COMPOST TOPDRESSING WHEN MANAGING ATHLETIC FIELDS ORGANICALLY Brian J. Tencza and Jason J. Henderson Department of Plant Science and Landscape Architecture University of Connecticut Preliminary results of multi-year study show positive results on turf color, plant cover, and soil properties from annual topdressing with compost
What About Phosphorus? Compost used on established turf must be used in compliance with state regulations regarding Phosphorus fertilizers. Soil must be tested to show need for P. In most states (with the exception of CT) composts and organic products are exempted. Composts and organic products can be used when making repairs or seeding.
Tree and Shrub Planting Agresource Inc. 100 Main St. Amesbury MA 01913
Planting Beds Agresource Inc. 100 Main St. Amesbury MA 01913
Wetlands Agresource Inc. 100 Main St. Amesbury MA 01913
Manufactured Wetland Soil High Organic Matter Content 20% organic content, (=12 % org. carbon) US Army Corp of Engineers Due to relatively high rates of compost require composts with low nutrient levels.
Wetland Soil Properties Wetland with quality soil produces: More rapid plant establishment Higher rate of plant survivability Increased floodwater retention Soil with SOM content of 20% will hold 4.89 gallons/cubic foot
Green Roof
Green Roof Functions Reduce heat island effects Capture and filter rainwater and reduce flow to storm water systems Soil Media Must: Support plant growth Allow for rapid infiltration of water Hold water but meet maximum bulk density when saturated
Infiltration Basins and Rain Gardens
Infiltration Basins and Rain Gardens Designed to treat storm water Rapid water infiltration Ability to filter and absorb nutrients Soils Must: Provide for rapid infiltration Have adequate Organic Matter to support plant growth and absorb nutrients
Bioretention Basin Soil Mix Goals: 1. Rapid Infiltration Rate 2. OM at 3 to 5 % Infiltration % OM Sand 24 in./hr 0.2 Mix 1 0.3 in./hr 5.3 (1:1; Sand:Compost) Mix 2 1.1 in./hr 3.4 (2:1; Sand: Compost)
What about the bugs? Composts contain diverse communities of different microorganisms. Laboratory studies and controlled field trials demonstrate that the compost microbes can suppress various soil borne pathogens There is little evidence that the differences in microbial populations will result in better plant growth The benefits of using compost to improve soil, physical and biochemical, are significant enough to justify using compost
Conclusions Composts can be used in a variety of applications as part of sustainable landscaping. Benefits include reduced use of water and fertilizer. Carbon added to soil improves soil structure. Not all composts are the same. Match the compost to the intended use. Choose suppliers that can provide consistent products and provide test results.