LHAP 105 – Soils Review ENVIRONMENTAL STEWARDSHIP What is the #1 hot topic in sustainability? Water List 2 ways this can be attainedrain gardens, rain barrels , bioswales, permeable pavers, drip irrigation Give 1 example of a renewable resourcepave edge, mulch, crushed concrete for gravel, reusable garden containers What is the urban heat island effect?Cities hotter than surrounding area due to concrete and glass How can we reduce the heat island effect? paint everything white, plant more trees , green areas What is the basis of low impact development? Manage stormwater where it falls What is one example of low impact development? Constructed wetlands, stormwater ponds, raingardens, permeable pavers What are the 3 ethical principles of Permaculture? care of the earth, care of the people, fair share Once example of catch and store energyrain gardens, plant trees, solar panels Once example of integrate rather than segregatework together, plant in groups, take care of the soil microbes Is diversity an example of a permaculture principle? yes - diversity prevents disease and insect infestations and allow for better integration SOIL PROPERTIES AND COMPONENTS What is the name of the layers in a soil profile? horizons What is the composition (include %’s) of an ideal mineral soil? Mineral 45%, organic matter 5%, air 25%, water 25% What are the 3 soil separates that make up the mineral portion of the soil? Sand, silt, clay Choose sand(S), silt (Si) or clay (C) for the following statements _C__ is a secondary mineral composed of silicon and aluminum __S, Si_ is inert __S_ has the best drainage __C_ has high CEC __C_ has high water holding capacity __Si_ is the most erodible __C_ has the best nutrient holding capacity __C_ particles are less than .002 mm in diameter __S_ comes in very coarse, coarse, medium, fine and very fine __C_ the best at forming aggregates __S, Si__ comes from parent material (make sure you can answer some these same questions if given textural classes) Water holding pores are called micropores or capillary pores The 2 forces that hold water in the pore spaces against gravity are cohesion and adhesion Air pores are called macropores Water Storage If all the air pores are filled with air and all the water pores are filled with water the soil is said to be at field capacity When there is water in all the pores the soil is said to be saturated When there is no water in any of the pores the soil is said to be at permanent wilting point Where is water available(Available water) to the plant? Between field capacity and PWP FORMATION What are the 5 soil forming factors? COPT Climate, Organisms, Parent Material, Topography Time What factor has the most effect on vegetation? Climate Aspect refers to …… Topography What parent material is would you see at in old lake bottom deposits? Lacustrine What parent material can be described as unsorted rocks from boulders to fine clays? Glacial Till PHYSICAL PROPERTIES PHYSICAL PROPERTIES What is the textural class of a soil with 25% silt and 37% sand? Clay is 38% Textural class is clay loam If an aggregate is really easy to break what is you guesstimate clay content? Under 20% How are aggregates formed? Wetting and drying, freezing and thawing What makes them stable? Organic matter glues and gums What is ideal structure in the A horizon of a grassland or urban soil? granular What conclusions can you make about columnar structure in the B horizon? High in sodium salts How does prismatic and blocky structure affect root penetration and drainage? Promotes good root penetration and drainage ESSENTIAL NUTRIENTS What are the 3 primary macro nutrients? nitrogen, phosphorous , potassium Is hydrogen considered a plant nutrient? yes How is nitrogen added to the soil?air - electrical fixation (lightning), biological fixation (rhizobium), industrial fixation (fertilizers) organic matter - both plants and animals What are the 2 forms of nitrogen available to plants? NO3- (nitrate) NH4+ (ammonium) What is the difference in plant growth, leaching, plant preference and pH between the 2 forms? NO3- nitrate - more leaching, prefered by plants, raises pH ammonium (NH4+) less leaching, second preference by plants, makes soils more acidic (DON”T HAVE TO KNOW pH) What form of sulfur do plants use? sulfate SO4- How is elemental sulfur converted to sulfate? micro organisms - this is the same as any form of sulfur that converts to sulfate How do plants take up Phosphorous? as an anion (negative) How do plants take up potassium? K+ Which primary macronutrient is least available in our alkaline soils? phosphorous Why? ties up with calcium How would you make this nutrient more available? add organic matterWhat happens to calcium, magnesium and potassium in the soil? used by the plant, tied to exchange sites on clay and OM or in solution Which nutrient is most likely to leach from the soil? Nitrate, potassium, ammonium, calcium - because it’s negative COMPACTION What part of the soil is most affected by compaction? Air pores If a 100 cc volume of soil weighs 126 g what is the bulk density? Dry weight/ volume = 126/100 = 1.26 g/cc Does this indicate compaction in a loam soil or not? no What bulk density is classified as root limiting? Above 1.6 List 2 predesign recommendations to prevent compaction? See list in powerpoint List 2 guidelines during construction to prevent compaction See list in powerpoint List 2 guidelines to ameliorate compaction. See list in powerpoint CHEMICAL FACTORS What is CEC? Cation Exchange Capacity What 2 components in the soil have a high CEC? Clay and Organic Matter What does it mean if the soil test report says the base saturation is 100%? All of the cations on the exchange sites are base cations Ca, Mg, K, Na What assumption could you make in regards to the pH of the above? alkaline At what pH are the following nutrients readily available? Sodium (Na) ___above 8.5___________ Calcium and magnesium __7.2-8.4________ Nitrogen, Phosphorous, Potassium ___neutral________ Micronutrients __slightly acid____________ At what pH do we see iron deficiencies? What does iron deficiency look like? Alkaline pH, interveinal chlorosis Which 2 ions are soluble enough at low pH to become toxic? Iron and aluminum At what pH does deflocculation occur? High as a result of sodium, low as a result of aluminum At what pH are most microorganisms active? 6-8 Where does phosphorous get tied up? 7.2- 8.4 and below 5.5 How would you acidify a soil high in pH? Add sulfur How would you increase the soil pH? Add lime What is active acidity? Amount of hydrogen in soil solution Define buffer capacity. What does EC measure? Define buffer capacity. Ability of soil to resist a change in pH. Determined by how many exchange sites are on the particles What does EC measure? Electrical conduction determines soluble salts in solution What does a really low EC indicate? Really low soluble salts which means really low fertility What do excess sodium salts in the soil do … To the soil _deflocculation causing problems with drainage and root penetration, tie up of other nutrients To the plant _reverse osmosis resulting in wilting, toxicity How do saline soils affect plant material? Reverse osmosis resulting in wilting, may cause nutrient deficiencies or ‘physiological drought’ How do you test for carbonates? Mild acid What effect do carbonates have on soil chemistry? Will tie up nutrients like P, Fe, Mn How would you ameliorate carbonates in the soil? Add organic matter What does SAR stand for? Sodium adsorption ratio Explain SAR Relationship between Ca and Mg to sodium BIOLOGICAL PROPERTIES What do microorganisms do in the soil? Break down OM, convert nutrients to plant available forms What conditions do they need? Air, water, food, neutral pH, no toxins, What is the function of rhizobium? Convert N2 to NH4 What is the function of mycorrhizae? Increase nutrient absorbing potential of plants What roll do microorganisms play in the nitrogen and sulfur cycle? Convert to plant available forms NH4 and NO3 What is ideal C:N ratio? 33:1 Give an example of an organic component with a high C:N ratio (400:1) sawdust What happens if the organic matter is too high in carbon? They steal nitrogen - Nitrogen drawdown or nitrogen deficiency in the plant material What would break down last? Glucose, sugars, proteins, lignin lignins What is stable organic matter called? humus What is the purpose of a bioassay or other seed germination test? Test for toxins in organic matter What does CCME look at when qualifying compost? Heavy metal content, foreign material, toxins, pathogens SOIL SAMPLING How many core samples would you take in an average lawn area? 1 10 30 50 100 How deep would you sample for a lawn area? 10-15 cm How are samples handled before they go to the lab? Air dry or cool T F sample the whole area no matter what the soil texture or topography When can you sample problem soils? anytime WATER QUALITY What 2 pieces of information do you need to determine water quality ? EC and SAR What is a high SAR? Anything over 9 is limiting. 12 is toxic What minerals are in hard water? Calcium and magnesium What mineral is predominant in soft water? sodium Amendment strategies for poor quality water? Use as little water as possible by mulching, rain capture etc How does soil temperature affect plants and water organisms? Too warm temperatures will destroy or change water organisms including fish Too cold will affect tropical plants used to warmer temperatures What does turbidity measure? Sediment What is one way to remove suspended sediment in pond construction? The use of Forebays or filters Which level of government is responsible for drinking water distribution and waste water treatment? Municipal The” Water for Life” policy is federal, provincial, municipal EPEA( Environmental Protection and Enhancement) is a Federal, Provincial, Municipal Act responsible to protect water from things like pesticides and industrial emissions. What are the 2 federals Acts (listed in the module) that the Federal Government is responsible for? Fisheries Act and Navigable Waters Protection Act What causes Eutrophication? Runoff of excessive amounts of nutrients into a body of water. Usually nitrates and phosphates. Causes dense plant life (algae) decreasing oxygen and resulting in death of animal life. CONTAINER MEDIA Which media component is used as a base and has a really low pH? peatmoss Which media component is sometime substituted for peatmoss but is easier to wet and more renewable? COIR - coconut fibre Which media component may require a wetting agent as an amendment because of its hydrophobicity? peatmoss Which media component would increase the bulk density of the mix? sand or mineral soil Which media component will crush if over mixed? perlite Which media component, composed of expanded mica, has a med-high CEC? vermiculite Which media component is used almost exclusively for hydroponics or in slabs for vegetable production? rockwool What does it mean when a media component is stable? won’t break down quickly In what application would you use fritted trace elements? when creating a mix When would you use chelated trace elements? when a nutrient deficiency is detected - fast release What is the purpose of adding dolomitic limestone to your mix? increase pH and add magnesium What media component, used to increase air spaces, may contain high amounts of fluoride? perlite