Victoria Master Gardeners Association Advanced Master Gardeners Soils Blocks 7 and Prepared by: Geoff Hughes-Games, PAg 1

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1 1 Prepared by: Geoff Hughes-Games, PAg 1

2 Block lots to cover! Soil ph, CEC - reminders Nutrients deficiencies Ideal nutrient ratios Soil tests/labs results/ test methods What does your soil test mean. Organic fertilizers pro/con Acidification/salt index of various fertilizers N-P-K Calculating applications rates Organic fertilizers meals, minerals, rates of release, organic Composts/manure Mulches Cover crops Lime/gypsum/sulfur 2 Prepared by: Geoff Hughes-Games, PAg 2

3 ph reminder managed soils natural coastal soils ph impacts: nutrient availability microbial (soil bugs ) activity bacterial 7.0 to 7.5 fungal 5.5 to 7.0 ph can be managed 3 Prepared by: Geoff Hughes-Games, PAg 3

4 Cation Exchange Capacity - reminder Relative ability of soil to adsorb exchangeable cations Driven by organic matter and clay (content/type) Order of bond strength: Al 3+ > Ca 2+ > Mg 2+ > K 2+ = NH 4+ > N + Units: meq/100g (milliequivalents charge per 100 gm dry soil) or cmol c /kg (centimoles charge per kilogram of soil) Colloid Approximate CEC (cmol c /kg) Kaolinite 3 15 Montmorillonite 100 Fe/Al oxides 3 Organic Matter Amorphous minerals Prepared by: Geoff Hughes-Games, PAg 4

5 Relationship between ph and CEC 5 Prepared by: Geoff Hughes-Games, PAg 5

6 Factor Affect on Nutrient Availability ph Optimum 6.0 and 7.0 As levels increase or decrease from this level, availability is reduced Organic matter Generally increases the potential availability of micronutrients, bind nutrients, limiting availability Soil texture Coarse soils have less capacity to hold nutrients Fine textured soils tend to bind nutrients in forms not available to plants Leaching from sandy soils Soil compaction in fine soils Nitrogen, sulfur, chlorine and boron are subject to leaching Compacted soils can limit the amount of water and air available, which in turn reduces nutrient release to plant available from OM and minerals Climate Extremes of moisture or temperature will accentuate deficiencies. Excess moisture reduces yield potential and increases leaching of some nutrients Dry conditions discourage root activity and reduce OM breakdown and flow of nutrients to the plant. Cool temperatures reduce OM breakdown and uptake of nutrients phosphate has been estimated to be 3 times more available at soil temperatures of 21 C 13 C, boron deficiencies and nitrate excesses tend to be greatest under cloudy cool conditions Crop removal Greater crop removal also means greater nutrient removal. Specific demands of crops Different crops have different nutrient requirements. Nutrient interactions Soil chemistry is complex. Addition of nutrients will affect existing nutrient levels and added nutrients High phosphate levels may reduce zinc uptake, high calcium levels can decrease boron uptake and copper will influence iron 6 Prepared by: Geoff Hughes-Games, PAg 6

7 More Factors Affecting Nutrient Availability Soil Mobility Nutrients Results Somewhat immobile in soil Mobile in soil Nitrogen, Sulfur, Boron Very immobile in soil Potassium, Calcium, Magnesium Phosphate, Iron, Manganese, Copper, Zinc Greater availability to plant Prone to leaching Moves short distances Low availability High application rates allow for more uptake by root interception (eg. phosphate) Chelating aids in mobility and uptake (micronutrients) Plant Mobility Nutrients Results Mobile in plant Nitrogen, Phosphate, Potassium, Magnesium Deficiency symptoms appear on older leaves as nutrients move to new growth Somewhat immobile in plant Sulfur, Iron, Manganese, Copper, Zinc Deficiency symptoms appear on new growth, nutrients don t translocate Very immobile in plant Boron, Calcium Deficiency symptoms appear on new growth 7 Prepared by: Geoff Hughes-Games, PAg 7

8 Plants are made up of Nutrients 8 Prepared by: Geoff Hughes-Games, PAg 8

9 Macro Primary Plant Nutrients Micro Secondary Metals Nitrogen (N) Calcium (Ca) Boron (B) Arsenic (As) Phosphorus (P) Magnesium (Mg) Chlorine (Cl) Cobalt (Co) Potassium (K) Sulfur (S) Copper (Cu) Cadmium (Cd) Iron (Fe) Manganese (Mn) Zinc (Zn) Molybdenum (Mo) Nickel (N) Chromium (Cr) Lead (Pb) Mercury (Hg) Selenium (Se)* Aluminum (Al) Zinc (Zn) Carbon (C) Hydrogen (H) Nickel (N) Molybdenum (Mo) Oxygen (O) Silicon (Si)* Sodium (Na)* Copper (Cu) 9 Prepared by: Geoff Hughes-Games, PAg 9

10 Nutrient movement to roots Movement Nutrients to the root Mass flow Diffusion dissolved nutrients move to plant roots as the plant absorbs water for transpiration. movement of nutrients to the root surface in response to a concentration gradient nitrate, sulfate, calcium and magnesium phosphorus and potassium Root interception growth of a root causes contact with soil colloids which contain nutrients calcium and magnesium into the root Active Passive energy required; the nutrient is moved into the root by a "carrier" molecule or ion no energy required; the nutrient enters with water Facilitated microbial assistance Examples: Rhizobia nitrogen fixing bacteria Mychorrhizal mainly phosphorus moving fungi 10 Prepared by: Geoff Hughes-Games, PAg 10

11 Typical signs of nutrient deficiency 11 Source: accessed Nov. 19, 2017 Prepared by: Geoff Hughes-Games, PAg 11

12 Typical Nutrient Deficiency Symptoms Symptoms N P K Ca S Mg Fe Mn B Mo Zn Cu Over fertilization Yellow Upper Leaves N N N N Y N Y N N N N N N Yellow Middle Leaves N N N N N N N N N Y N N N Yellow Lower Leaves Y Y Y N N Y N N N N N N N Red Stems Y Y Y N N Y N N N N N N N Necrosis N N Y N N Y N Y Y N N Y N Spots N N N N N N N Y N N N N N Growing Shoots Die N N N N N N N N Y N N N N White Leaf Tips N N N N N Y N N N N Y N N Stunted Growth Y Y N Y N N N N N N N N N Deformed New Tips N Y N N N N N N N N N N N Yellow Tips N N N N N N N N N N N N Y Twisted Growth N N N N N N N N Y N N N N Various sources: (all accessed Nov 19, 2017) Western Fertilizer Handbook 9 nd Ed, 2002, Chapter 4 Essential Plant Nutrients Royal Horticultural Society Nutrient Deficiencies Guide to Symptoms of Plant Nutrient Deficiencies AZ Key to Nutrient Deficiencies in Vegetable Crops Nutrient Disorders in Fruit Trees PNW 121E 12 Prepared by: Geoff Hughes-Games, PAg 12

13 Nitrogen (N) cycle 13 losses Source: accessed on Nov 19, 2017 Prepared by: Geoff Hughes-Games, PAg 13

14 Nitrogen Forms: Nitrogen (N) Nitrate (NO 3- ) Ammonium (NH 4+ ) Organic N Atmospheric N (N 2 O, NO, N 2, NH 3 ) Key role for plants: Chlorophyll - photosynthesis amino acids and proteins DNA hormones 14 Prepared by: Geoff Hughes-Games, PAg 14

15 Nitrogen very dynamic and be easily lost environmental and human health concerns Sources: Fertilizer Residual soil N Legumes (fixation) Atmosphere Decomposition of plant and animal residue Mineralization of soil organic matter Irrigation water Losses: Crop removal nitrate/ammonium Leaching nitrate Denitrification N 2, N 2 O, NO Volatilization Ammonium (ph ) 15 Prepared by: Geoff Hughes-Games, PAg 15

16 Nitrogen Deficiency slow growth - stunted yellow or pale green colour (chlorosis) dead on tips or margins leaves (necrosis) starts with mature leaves 16 Prepared by: Geoff Hughes-Games, PAg 16

17 Phosphorus (P) cycle Source: accessed Nov. 19, Prepared by: Geoff Hughes-Games, PAg 17

18 Phosphorus roles Roles in plant: energy transfer cell membranes seed/root development enzyme regulation DNA Issues: low availability low mobility environmental damage 18 Prepared by: Geoff Hughes-Games, PAg 18

19 Phosphorus forms Soluble P Orthophosphate (PO 4 3- ) Organic P Labile P Organic Inorganic Stable (non-labile) P Tightly bound to or in soil particles Organic Inorganic Organic [Humus][ PO 4 3- ] Residues Inorganic (ph) [Calcium][ PO 4 3- ] [Aluminum][ PO 4 3- ] [Iron][ PO 4 3- ] [Clay][ PO 4 3- ] 19 Prepared by: Geoff Hughes-Games, PAg 19

20 Phosphorus Deficiency slow growth - stunted plants purple colouration on foliage of some plants (old/new) poor seed/fruit development delayed maturity dark green 20 Prepared by: Geoff Hughes-Games, PAg 20

21 Potassium (K) cycle Source: accessed Nov. 19, Prepared by: Geoff Hughes-Games, PAg 21

22 Potassium Roles in Plant: photosynthesis and respiration rate enzyme/energy transfer and storage cell division and enlargement osmotic pressure/turgor transfer of heredity traits winter survival/ drought stress fosters nitrate-nitrogen (N) uptake and protein synthesis seed formation Issues: low availability not a concern environmentally or human health can be an animal health concern 22 Prepared by: Geoff Hughes-Games, PAg 22

23 Potassium Deficiency slow growth tip and marginal chlorosis necrosis starts with mature leaves small fruit/shriveled seeds weak stems and stalks poor winter survival 23 Prepared by: Geoff Hughes-Games, PAg 23

24 Soil Food Web what is your plant choice? Fungal dominated VS Bacteria dominated 1. Most perennials, shrubs and trees prefer their nitrogen in ammonium form and do best in fungal dominated soils. 2. Aged, brown mulches support fungal growth. 3. Mulch laid on the surface tends to support fungi. 4. Coarse, dryer mulches support fungal activity. 5. Kelp, humic and fulvic acids and phosphate rock dusts help fungi grow. 6. The roots of most conifers as well as hardwood trees form mycorrhizae with Ectomycorrhizal fungi. 7. Most vegetables, annuals, grasses, perennials, shrubs and softwood trees form mycorrhizae with Endomycorrhizal fungi. 1. Most vegetables, annuals and grasses prefer their nitrogen in nitrate form and do best in bacterially dominated soils. 2. Fresh, green mulches tend to support bacterial populations. 3. Sugars help the bacteria multiply and grow. 4. Mulch worked into the soil tends to support bacteria. 5. If you wet and grind mulch thoroughly, it speeds up bacterial colonization. These rules (from Teaming with Microbes ) argue that the levels bacteria or fungi drive the food web and the plant ecology. 24 Prepared by: Geoff Hughes-Games, PAg 24

25 4 R s of Nutrient Management Right: Source Rate Time Placement plant available matches soil character crop sensitivity interactions between sources compatibility if blending non-nutritive elements soil supply availability form all sources crop demand fertilizer efficiency seasonal variability nutrient budget (crop/soil/environment) economics crop uptake soil nutrient supply release of nutrients from fertilizers weather logistics soil root dynamics variability of soil cultivation system potential loss mechanisms Source: (accessed Nov 19, 2017) 25 Prepared by: Geoff Hughes-Games, PAg 25

26 Mineral fertilizers raw or processed Organic sources Nutrient sources livestock manures crop residues composts organic residuals mined sources 26 Prepared by: Geoff Hughes-Games, PAg 26

27 Fertilizer Bag Labels Guarantee: Governed by Federal Fertilizers Act % nitrogen % phosphate % potash Nitrogen as N Phosphate = units of Phosphorus (P) 1 kg P = 2.3 kg phosphate (P 2 O 5 ) Potash = units of Potassium (K) 1 kg K = 1.2 kg potash (K 2 O) 27 Prepared by: Geoff Hughes-Games, PAg 27

28 Fertilizer sources non-organic Considerations: Salt index Acidification index Contaminants Trace elements Release rates analysis chemical compound Ammonium sulfate Calcium nitrate salt index acidification 69 very acid 53 alkaline urea 75 acid Potassium chloride Potassium sulfate Treble super phosphate 116 neutral 46 neutral 10 neutral 28 Prepared by: Geoff Hughes-Games, PAg 28

29 Nutrient content of non-organic fertilizers N P 2 O 5 K 2 O S Ammonium sulfate Urea Muriate of Potash Sulphate of Potash Triple super phosphate Diammonium phosphate Blends w/ or w/o micro nutrients Slow release Soluble or liquid % Depends on crop and season May be sulfur, polymer or resin coated or integrated Maybe readily soluble or available in liquid 29 Prepared by: Geoff Hughes-Games, PAg 29

30 Examples of other organic materials used in gardens spent mushroom media animal manure composted or raw Compost (various sources of raw materials) wood ash (bottom of fly) packaged products seed / vegetation meals animal based (blood, bone, fish) meals kelp guano microbial preparations green manure / cover crops byproducts treated (e.g., biosolids) 30 Prepared by: Geoff Hughes-Games, PAg 30

31 Nutrient content of organic materials N P 2 O 5 K 2 O duration rate % dry weight months Pounds / 100 ft 2 Alfalfa meal Soya meal Bone meal Blood meal Green sand Rock phosphate 0 30* yrs 2.5 Spent mushroom compost < 1 20 < Wood ash yrs 3.5 Sea soil (Original) 2.1 <1 <1-32 L/9 ft 2 Kelp (1 lb dry = 9 lb wet) Sulphate of potash magnesia Fish meal Prepared by: Geoff Hughes-Games, PAg 31

32 Manure nutrient contents Solid Manure Type D.M. Available N Available P Available K 2 0 Materials % kg/tonne (or g/kg) Horses average Sheep average Beef 30% Beef 18%-30% Dairy 18%-30% Dairy 30% Poultry layers Poultry broilers Hog **** Values vary with diet, bedding, housing, climate, breed, storage 32 Prepared by: Geoff Hughes-Games, PAg 32

33 Has the soil been sampled and tested? What parameters, by whom and how? Most common to look for nutrients, salts, ph, organic matter. You can start with Look, feel, smell, (taste) Plant growth then Quick test (reliable?) Lab test (time and cost) 33 Prepared by: Geoff Hughes-Games, PAg 33

34 Why Soil Test? Too look for: nutrients contaminants biological activity soil quality 34 Prepared by: Geoff Hughes-Games, PAg 34

35 Example soil test what does it mean? 35 Prepared by: Geoff Hughes-Games, PAg 35

36 Analysis mg/kg = ppm High N Very High OM, P, Ca Med High S Low K High ph Low EC Lab Recommendation: Nitrogen 1.5 lb/1000 ft 2 Potassium 2.7 lb/1000 ft 2 36 Prepared by: Geoff Hughes-Games, PAg 36

37 Cd Reduction; Nitrate- Nitrogen LOI (τ ) Mehlich 3 Ammonium Acetate Ammonium Acetate Ammonium Acetate Ammonium Acetate Ammonium Acetate DTPA DTPA DTPA DTP A 1:1 water:soil Soluble Salts Soil test data Method Units mg/kg; NO 3 -N ppm % mg/kg; ppm P mg/kg; ppm K mg/kg; ppm S mg/kg; ppm Ca mg/kg; ppm Mg mg/kg; ppm Na mg/kg; ppm Zn mg/kg; ppm Fe mg/kg; ppm Mn mg/kg; ppm Cu mmho/cm ph Buffer ph N OM P K S Ca Mg Na Zn Fe Mn Cu Salts Max Min Median Average Target >10 <100 <250 >20 >650 >100 **<18 >2.5 >50 <15 >0.5 <1.0 Ca:Mg Ca:K Mg:K CEC % H % K % Ca % Mg % Na Max Min Median Average Target Prepared by: Geoff Hughes-Games, PAg 37

38 How much nutrients are needed? Calculating based on soil test? Or just guessing? 38 Prepared by: Geoff Hughes-Games, PAg 38

39 Practices and Philosophy Sampling techniques Lab testing methods Kelowna, Bray P1, Mehlich 3, Olsen (bicarbonate) Ammonium Acetate, Modified Kelowna, Mehlich 1 Colorimetric / quick tests Recommendation philosophy Sufficiency Level of Available Nutrient (SLAN), or Crop Nutrient Requirement (CNR) Build-Up and Maintenance - building soil fertility level to the high category with additions of specific nutrients whose indexes were interpreted as medium or lower per the soil test. Basic Cation Saturation Ratio (BCSR) concept or Cation Ratio Concept - focus on the cations K, Mg, and Ca by attempting to maintain desired ratios of these cations on the soil cationexchange complex desirable distribution of exchangeable nutrients is 65% Ca, 10% Mg, 5% K, and 20% H resulting desired ratios of 6.5Ca:1Mg, 13Ca:1K, and 2Mg:1K. Source and form of nutrients Local vs imported Synthetic vs organic 39 Prepared by: Geoff Hughes-Games, PAg 39

40 Steps to Calculating Fertilizer Application Rate Example is for a 40-foot by 100-foot garden area, using a fertilizer 1. Calculating size of area to be fertilized ft. long X ft. wide = square feet Example: 40 feet X 100 feet = 4000 square feet 2. Calculating fertilizer application rate lb. nutrient per sq. ft = pounds fertilizer / sq. ft. % nutrient in fertilizer Example: 1 lb. nutrient per 1000 sq. ft = 5.5 pounds. fertilizer / 1000 sq. ft. 18% nutrient in fertilizer 3. Calculating pounds of fertilizer to apply lawn or garden application rate = pound of fertilizer area X per garden or lawn sq. ft. pounds fertilizer pounds fertilizer X = garden or lawn sq. ft. garden or lawn Example: 4000 sq. ft. 5.5 pounds fertilizer 22 pounds fertilizer X = lawn 1000 sq. ft. lawn 40 Prepared by: Geoff Hughes-Games, PAg 40

41 Soil Food Web compost and management? 1. Compost will inoculate the soil food web. 2. Compost can be used to inoculate beneficial microbes into soils and introduce, maintain or alter the soil food web in an area. 3. Compost/added nutrients, can make teas that are fungal dominated, bacterially dominated or an even ratio of both. 4. Compost teas are very sensitive to chlorine and preservatives. 5. Applications of synthetic fertilizers kill off or damage the soil food web. 6. High NPK additives should be avoided. 7. Use compost tea reduce impact of chemical spraying or soil drenching. 8. Excessive soil turning destroys or severely damages the soil food web. 9. Use endomycorrhizal fungi compost when planting or transplanting seeds of annuals and vegetables. These rules (from Teaming with Microbes ) argue that compost is the answer to maintain or improving the soil food web. Prepared by: Geoff Hughes-Games, PAg 41

42 4 2 Compost and Composting Prepared by: Geoff Hughes-Games, PAg 42

43 Composting The controlled biological oxidation and decomposition of organic matter based on time and temperature criteria defined by raw materials and end use 43 Prepared by: Geoff Hughes-Games, PAg 43

44 Composting Material sources: yard waste food waste farm wastes (manure or vegetation) wood waste municipal solids wastes (organic) biosolids or processing wastes or combinations 44 Prepared by: Geoff Hughes-Games, PAg 44

45 Composting Process starting carbon to nitrogen (C:N) ratio [30:1]* moisture [50-60%]* particle size (ideal 1.5 to 8 cm L/W and less than 5 (D)* variable size distribution [impacts oxygen content]* ph 5.5 to 8.5 Temperature: up to 40 C mesophilic bacteria, 40 C to 65 C thermophilic bacteria Volume (backyard 1 m 3 ) aeration (turning or blowers) [impacts oxygen content]* 45 Prepared by: Geoff Hughes-Games, PAg 45

46 4 6 Composting Process Passive prepare materials chip/grind premix layer Active prepare materials routine turning moisture management Prepared by: Geoff Hughes-Games, PAg 46

47 Compost Temperature Temperature is driven by type of organisms active in pile Controlled by moisture, aeration, ph and raw materials (i.e., C:N ratio) Control of pathogens and weeds requires heating 47 Prepared by: Geoff Hughes-Games, PAg 47

48 Compost: Do s, Don t and Maybes Do use green & brown chip, shred, grind use range of particle sizes mix/turn control moisture turn regularly Don t add putrescible stuff (meat, dairy, pet feces) avoid containments (oil, paint, plastic) dry/wet compact pile 63 Prepared by: Geoff Hughes-Games, PAg 48

49 Quality general for standard landscape uses: Compost Quality (MetroVan) 49 Prepared by: Geoff Hughes-Games, PAg 49

50 Compost and Soil metals limits - OMRR For sales of compost: Federal Fertilizers Act and CCME BNQ guidelines Accessed Nov 19, Prepared by: Geoff Hughes-Games, PAg 50

51 Pathogen Survival Human and Animal Pathogens in Manure Merle E. Olson, Microbiology and Infectious Diseases, University of Calgary Source: accessed Nov 19, Prepared by: Geoff Hughes-Games, PAg 51

52 5 2 Using organic materials? mulch or incorporate Compost Use Rates: Garden beds: 1 2 incorporated to 6 8 Turf top dress: Soil mix: 20 50% inclusion Mulch: 2 3 Other materials: Dependent on material (wood chips, bark, shavings, straw, etc.) Prepared by: Geoff Hughes-Games, PAg 52

53 5 3 Using organic materials? mulch or incorporate Incorporate (as fertilizer or conditioner) if building a soil or planting bed to improve structure, water holding capacity, and nutrient content C:N Ratio - less than 40:1 for incorporated materials Mulch yard waste, wood waste, high C:N ratio compost, etc. particle size: larger than 2.5 cm should not be deeper than 5 to 7 cm will reduce evaporation by as much as 70% Prepared by: Geoff Hughes-Games, PAg 53

54 5 4 Using organic materials? mulch or incorporate Compost Rates: Garden beds: 1 2 incorporated to 6 8 Turf top dress: Soil mix: 20 50% inclusion Mulch: 2 3 Other materials: Dependent on material Prepared by: Geoff Hughes-Games, PAg 54

55 Cover Crops type grass cereal legume brassica other broadleaf annual vs perennial winter survival weedy pest / disease bridge nutrient management 55 Prepared by: Geoff Hughes-Games, PAg 55

56 Increasing soil ph lime (CaCO 3 ) neutralizes acidity lime also supplies Calcium (Ca), which is often deficient in acid soils Dolomite lime also supplies Magnesium (Mg) comprised 50% calcium carbonate, and 40% magnesium carbonate apply lime based on: Apply lime based on: a soil test type of crop being grown for gardens without a soil test: 25 kg/100 m 2 /year 56 Prepared by: Geoff Hughes-Games, PAg 56

57 Decreasing soil ph use finely ground sulfur (S) or pelletized with clay for gardens without a soil test 5 to 10 kg S/100 m 2 for sandy soils 20 to 25 kg S/100 m 2 for clayey soils must be well mixed incorporate to 30cm for trees and shrubs ammonium sulfate, aluminum sulfate and iron sulfate will decrease soil ph slowly while supplying N, Al, Fe 57 Prepared by: Geoff Hughes-Games, PAg 57

58 58 Prepared by: Geoff Hughes-Games, PAg 58