Slide 1 Organic Matter The Organic Component to Soils Slide 2 https://www.no-tillfarmer.com/articles/6042-shoot-for-higher-organic-matter-by-relying-on-residue?v=preview Slide 3 provides a source of energy for soil organisms supplies most of the natural soil nitrogen, half of the phosphorus a major portion of sulfur, and many organic compounds Organic matter a Major Component Slide 4 contributes to the CEC (the reservoir for plant-available nutrient storage) enhances soil structure needed for gaseous diffusion, water movement & storage, root penetration & extension (soil for projects are usually low in OM so supplementation is often necessary) Organic matter a Major Component Slide 5 https://www.pitchcare.com/news-media/soil-organic-matter-is-good.html (SOM) Slide 6 Changing Forms of SOM Slide 7 1. Additions Fresh Residue - dead roots and leaves and other plant parts bodies of animals ( macro and micro) Slide 8 2. Transformations Active organic matter - Soil organisms continually change organic compounds from one form to another. They consume plant residue and other organic matter, and then create by-products, wastes, and cell tissue Slide 9 3. Microbes feed plants Some of the wastes released by soil organisms are nutrients that can be used by plants. Slide 10 Stabilization of Organic Matter Stable Organic Matter - Eventually, soil organic compounds become stabilized and resistant to further changes (HUMUS) Slide 11 Dead Plant Material animal & other organic substances Soil Organic Matter includes: Slide 12 Organic compounds This is what can be used as food by microorganisms Soil Organic Matter includes: Slide 13 Root Exudates: soluble sugars, amino acids and other compounds secreted by roots ( these are easily digested by bacteria) Soil Organic Matter includes: Slide 14 Lignin: hard to degrade some fungi can use this as food Soil Organic Matter includes: Slide 15 Humus: not readily decomposed physically protected within aggregates (binding agent) chemically too complex to be used by microorganisms Soil Organic Matter includes: Slide 16 Types of Organic Matter WOOD PRODUCTS Chipped wood and bark, shredded leaves, sawdust if properly composted and screened - can be very good Slide 17 Plant Residues Many products are very coarse(unscreened) for a mix component Wood chips, bark, and shavings used alone are best for mulching rather in a mix mulches - we do not want fast decomposition Slide 18 Plant Residues Sawdust is very raw - do not use it alone - high C:N ratio ( discussed later in this presentation) so decomposes slowly - do not use in a mix unless fully composted Slide 19 Type of Organic Matter FOOD(kitchen)WASTE a wide variety of materials are being marketed( worm castings, sea kelp) Slide 20 Types of Organic Matter PLANT DEBRIS Slide 21 Manures manures require composting to reduce C:N ratio, odour and pathogens desirable when finely screened horse and cow are preferred (contains bedding material) over sheep and hog Slide 22 Manures Poultry manure is considered “hot” best mixed with other manures or composting Slide 23 Standards - Biosolids in Canada – Canadian Council of Ministers of the Environment Guidelines in US - must meet EPA Part 503 Grade A “exceptional quality” CCME Guidelines CFIA Compost Regulation Slide 24 StandardsCarbon:Nitrogen Ratio plant tissue and farm manure 20:1 stems of cereal crops (straw) 100:1 sawdust 400:1 soil organisms 4:1 to 9:1 Slide 25 Carbon:Nitrogen Ratio material decomposes faster when the nitrogen is available to the decomposing microorganisms Slide 26 Carbon:Nitrogen when the compost is added to the soil, it should have a C:N of about 33:1 this ensures that there is Nitrogen for the plant roots as the material decomposes further high C:N ratio - nitrogen drawdown Slide 27 StandardsSoil Reaction pH as organic matter decomposes the pH changes as well as the C:N ratio High C:N ratio materials are usually acidic (4.5 - 6.0) as C:N narrows during composting the pH tends to rise. (usually 6.0 - 7.0) Slide 28 StandardsStability stability refers to the stage of compost decomposition CO2, heat, and water vapour are produced a stable residue results - when little further decomposition occurs Slide 29 Stability to measure stability measure the heat evolution from a moist sample (self - heating test) Measure CO2 evolution from a sample as produced by the microorganisms on oxygen uptake Slide 30 StandardsMaturity Criterion: measures the acceptability of a compost for planting growth - screening procedures such as seed germination tests and subsequent plant growth and survival pot tests and root elongation tests Slide 31 Maturity These tests detect the presence of: volatile fatty acids*, alcohols*, soluble salts, heavy metals, or ammonia * these are produced under anaerobic conditions Slide 32 Soil Organic Matter = HUMUS + Active organic matter Active organic matter is available to organisms. Bacteria use simple organic compounds (root exudates, fresh plant residue). Fungi use more complex compounds (fibrous plant residues, wood) Soil organisms convert soil organic matter to humus - a STABLE form of carbon sequestered in soils for decades, even centuries! Slide 33 Organic matter vs Humus Slide 34 Humic Acid C187H186O89N9S1 Slide 35 Properties of Humus Slide 36 Odour descriptive rather than quantitative factor stable compost should produce no unpleasant odour. They should smell a bit “musty” not sufficiently stable (cured) if smell like rotten eggs (H2S), ammonia, or other strong odour Slide 37 Organic Content may vary from 30 - 70% with a moisture content varying from 30 - 60% more than 50% is desirable with moisture of 40 to 50%. Bulk density should range from 450 to 550 kg per m3 Slide 38 Mineral Content the mineral content may range from 0 - 1.5% and reported as ash residue anything greater than this range will indicate other mineral impurities Slide 39 Coarseness related to the screen size used by the processor 25 mm screen vs 13 mm screen and smaller the coarseness permitted depends on the use (topdressing of turf should 6 mm screen) Slide 40 CEC CEC increases as the material decomposes Slide 41 Nutrient Contents nutrient contents of compost are low compared to commercial fertilizer materials more valuable contribution to the soils physical properties compost nutrient content ranges because of varying feedstock and processes used Slide 42 Company Mixes https://eaglelakelandscape.com/ Earthly Matters - Coaldale ( vermicompost) Annelida - https://annelida.ca/ ( vermicompost) Edmonton Eagle Lake - Strathmore