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What is pH ?. It’s the relative amount of H + ions in the “soil solution”. H +. H +. H +. H +. H +. H +. H +. H +. pH Scale. pH of some common substances . Concentration of H + ions compared to distilled water . pH. pH. 0. 0. 10,000,000. Battery acid. 1,000,000. 1. 1.
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What is pH? • It’s the relative amount of H+ ions in the “soil solution” H+ H+ H+ H+ H+ H+ H+ H+
pH Scale pH of some common substances Concentration of H+ ions compared to distilled water pH pH 0 0 10,000,000 Battery acid 1,000,000 1 1 Stomach acid 2 2 Lemon juice 100,000 Vinegar 10,000 3 3 Acid Orange juice 4 4 1,000 Tomatoes 5 5 100 Potatoes 10 6 6 Milk 1 NEUTRAL 7 7 Blood (7.35 – 7.45) 1 / 10 8 8 Chlorine bleach 1 / 100 9 9 Base Baking soda 10 10 1 / 1,000 (Alkaline) Household ammonia 1 / 10,000 11 11 Soap solutions 1 / 100,000 12 12 Hair remover 1 / 1,000,000 13 13 Lye 1 / 10,000,000 14 14
Soil pH The Widths of the Bars = the Availability of the Nutrients to Plants NEUTRAL OH- H+ ACID Alkaline 1 2 3 4 5 6 7 8 9 10 11 12 13 0 14 Nitrogen (N) Phos. (P) Potassium (K) Iron Deficiency Iron (Fe) Manganese Deficiency
H+ Ca C O3 H+ (Lime) How do you raise the soil pH? H+ H+ H+ H+ + H+ H+ H+ You Add Lime You must get rid of the H+ ions
H+ H+ How do you raise the soil pH? Leaves as Gas H+ H+ O2 O Ca C O3 H+ H+ H+ H+ H+ (carbon dioxide) H2 (water) pH pH Rises: Soil Becomes Less Acidic A
H+ Ions are Found in Two Places in the Soil H+ H+ H+ H+ Mg2 H H H H - - Ca2 K K - - H - - - - - - H - - H Floating Around in Soil Water (“Soil Solution”) H - H+ - K Clay Particle H - - H+ - - H - K - H H+ - - - - H - - - - H - - K Ca2 K H H H Mg2 H+ Attached to Clay Particles H+ H+
Ca Ca Ca Ca Ca C C C C C O3 O3 O3 O3 O3 (Lime) (Lime) (Lime) (Lime) (Lime) Lime First Affects the “Free” H+ H+ pH Rises: Soil Becomes Less Acidic H+ H+ H+ Mg2 H H H H - - Ca2 K K - - H - - - - - - H - - H H - H+ - K Clay Particle H - - H+ - - H - K - H H+ - - - - H - - - - H - - K pH pH Ca2 K H H H Mg2 H+ H+ H+
pH pH What About the H+ Ions Attached to the Clay Particle? They Can Detach From the Particle to Become “Free” H+Ions H+ Ions = Acid! Mg2 H pH pH H - - H H - Ca2 K K - - H - - - - - - H - H H - - K Clay Particle H - - - - - H K - - H - - - - - H - - - - H K Ca2 K H H H Mg2 pH Drops: Soil Becomes More Acidic
High or Low Reserve Acidity? - - - - H H H H High Reserve Acidity = High Buffering Capacity - - - - - - - - H H - - - - - - - - H H H H H H - - - - - - - - - - - - - - - - - - - - - - K K H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H Mg2 Mg2 - - - - - - - - - - - - - - - - - - Ca2 Ca2 Clay Particle Clay Particle Soil Chemistry: Some Terms High Reserve Acidity: Large number of H ions on particle • “Reserve Acidity”: • The H+ ions attached to the clay particles is the “reserve acidity.” • “Buffer”: • A buffer keeps pH at “status quo.” There is a resistance to being able to change the soil pH. • Buffering Capacity: • Describes the capacity for a particular soil to resist a change in pH. The greater the buffering capacity, the more difficult it is to change the pH.
H - - - - - H K K H Clay Particle - K - H - - - - - - - - - - - - - - - - - - K H K - - - - - - - - - - - - - H H H K Al3 - - - Al3 - - - - - - - - - - K K K H H H H H H H H H H H H H H H H H H H Ca2 Mg2 Ca2 Ca2 Mg2 - - - - - - - - - Ca2 Ca2 Mg2 Ca2 Clay Particle Soil Chemistry: • Soil A: Low Buffering Capacity • Low ratio of hydrogen compared to other elements • Means Low Reserve Acidity • Easy to change pH How Much Lime? • Soil B: High Buffering Capacity • High ratio of hydrogen compared to other elements • Means High Reserve Acidity • Hard to change pH How Much Lime?
What Does “Buffering” Mean to You? Lime Requirements
We want to raise pH to 6.3 Soil A: SOIL TEST LIME RECOMMENDATION: 10 lbs / 1000 sq.ft.
We want to raise pH to 6.3 Soil B: Soils A and B: Same starting pH, Same desired ending pH. Why does it take different amounts of lime? SOIL TEST LIME RECOMMENDATION: 20 lbs / 1000 sq.ft.
H - - - - - H K H K Clay Particle - K - H - - - - - - - - - - - - - - - - - - K K H - - - - - - - - - - - - - H H H K Al3 - - - Al3 - - - - - - - - - - K K K H H H H H H H H H H H H H H H H H H H Ca2 Mg2 Ca2 Ca2 Mg2 - - - - - - - - - Ca2 Ca2 Ca2 Mg2 Clay Particle Soil Chemistry: Soil A: 10 lbs. of Lime Soil B: 20 lbs. of Lime
What About Sulfur and pH? Sulfur Sulfur Sulfur 7.5 pH 7.8 7.0 6.5 Biological What's Happening? Chemical Physical
What About Sulfur and pH? Sulfur Gypsum H2SO4 + CaCO3 H2O + CO2 + CaSO4 Sulfuric Acid Lime / Calcite Soil Microbe pH
What About Sulfur and pH? Apocalyptic Result! Tens of Millions of Tons of Sulfur! Not Really!
What About Sulfur and pH? Acid-Loving Plants on Limestone/Calcite Soils Do Require Constant Applications of Acidifiers
The Soil Test * To convert lb/A (pounds per acre) to ppm (parts per million), divide by 2. Example: 100 lb/A = 50 ppm
Soil Additives: A Few Points • Gypsum • Calcium Sulfate: CaSO4 • A source of calcium (Ca) that does not affect soil pH • Used in place of Dolomitic Lime: CaMg(CO3)2 • Epsom Salt • Magnesium Sulfate: MgSO4 • A source of magnesium (Mg) that does not affect pH • Used in place of Dolomitic Lime
Macronutrients Nitrogen [N] Phosphorus [P] Potassium [K] Calcium [Ca] Magnesium [Mg] Sulfur [S] Micronutrients Iron [Fe] Manganese [Mn] Copper [Cu] Zinc [Zn] Molybdenum [Mo] Boron [B] Chlorine [Cl] Nickel [Ni] Fertilizer: Plant Nutrients Based on how much the plant uses, NOT on importance to plant health
The Rule of Limiting Factors How can we get information about the concentration of these nutrients in our soil?
SOIL TEST! * To convert lb/A (pounds per acre) to ppm (parts per million), divide by 2. Example: 100 lb/A = 50 ppm
Soil Testing Tips Soil Probe
As Soil Man Says: Don’t Guess Soil Test!
The Fertilizer Grade Fertilizer “Grade” Super-Special Plant Fertilizer • The Fertilizer Grade is the percent (%) by weight of: • Nitrogen (N) • Phosphorus (P) • Potassium Oxide (K) • 5% N; 10% P; 5% K 5 – 10 – 5 ACME Fertilizer Company
Fertilizer Calculations • A fertilizer recommendation calls for ½ lbs. of Phosphorus to be applied per 1,000 sq.ft. • You have a fertilizer with a grade of 5 - 10 – 5 • How much of this fertilizer must be applied per 1,000 sq.ft. to meet the recommendation? Recommended lbs. of Nutrient / 1000 sq.ft. (Convert lbs. to Decimal Form) 0.5 lbs. 5 lbs. of 5 - 10 – 5 per 1000 sq.ft. lbs. of the Fertilizer to apply per 1000 sq.ft. = % of the Nutrient in the Fertilizer (Convert % to Decimal Form) 0.10
I know nothing about steroid use Back to Physical Properties
Body-Building the Soil A Soil Structure
Building Soil: • It’s Like Building a House • Soil Texture • Soil Consistency • Soil Structure
Textural Triangle SILT CLAY SAND Building Soil: Some Terms and Concepts • It’s Like Building a House • Soil Texture • Soil Consistency • Soil Structure
Building Soil: • It’s Like Building a House • Soil Texture • Soil Consistency • Soil Structure
Soil Consistency • Describes the general organization of the soil • A particular soil consistency is often a temporary condition • Consistency uses the following categories: • Loose • Friable • Firm • Extremely Firm
Building Soil: • It’s Like Building a House • Soil Texture • Soil Consistency • Soil Structure
What is Soil Structure? It’s the FINAL Form of the Soil
Soil with Structure: Granular Blocky Columnar Platy
Soil Structure • Bad News: • Once soil structure is destroyed, it cannot be re-created to it’s original form • Good News: • Good soil structure can be recovered – if you understand how soil properties interact to create it.
Biological Soil Properties:They Are Not Independent! Chemical Physical
Clay and Flocculation: Mg++ Ca++ Polyvalent Cations Fe+++ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - "Flocculation" means "bringing together" - - - - - - Fe+++ - - - - - - - - - - - - - - - - - - Mg++ - - - - - - - - - - - - - - - Clay Particle Clay Particle Clay Particle Electrostatic Bonds
Clay and Humus: - - - - Humus Particle - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Fe+++ - - - - - - - - - - - - Mg++ - - - - - - - - - - Clay Particle Clay Particle Electrostatic Bonds
Flocculation The Beginning of Soil Structure Floccule Electrostatic Bonds
Soil Properties:They Are Not Independent! Biological Chemical Physical
Soil Biological Properties
Secrets of the Soil Forest Soils… ...the Holy Grail of soils
The Living Soil • What’s in 1 Cup of Healthy Forest Soil? • Arthropods: • 50,000 • Nematodes: • 100,000 • Protozoa: • 20 million • Bacteria: • 200 billion • Fungi: • 60 miles of fungal hyphae “If a healthy soil is full of death, it is also full of life: worms, fungi, microorganisms of all kinds ... Given only the health of the soil, nothing that dies is dead for very long.” -- Wendell Berry SQUIRMEES Source: Serita Frey, Univ. of New Hampshire
Soil Particles: Mineral and Organic Micropore Spaces Bacteria Fungal Hyphae Microbial “Glue” The Living Soil REMEMBER: It's not Super Glue! Microbial Glue: Sticks the Soil Particles Together SQUIRMEES