Abiotic Disorders: Soil and Fertilizer Components Janet Hartin UCCE Environmental Horticulturist San Bernardino, Los Angeles, and Riverside Counties

Mineral matter Organic matter Air Water Major Components

Physical Properties of Soil Soil texture Soil structure Soil color Bulk density

USDA Textural Triangle

Soil Textures

Examples of Soil Structure

Compaction Can Destroy Soil

Where Does Compost Fit In?

What is composting? Grass clippings Food scraps Leaves Using the natural process of decay to change organic wastes into a valuable humus-like material called compost Compost

Compost Promotes Soil Health Supplies organic matter to soil Attracts earthworms Stimulates beneficial soil microorganisms Increases soil and nutrient water holding capacity in sandy soils/drainage in heavy soils

Compost Supplies Some Plant Nutrients Compost is not a fertilizer, but does contain plant nutrients Nitrogen and phosphorus are mostly in organic forms – Released slowly to plants – Not readily leached from the topsoil Compost contains small amounts of nutrients that are essential for plant growth

When is Compost Ready? Compost is mature when It is dark brown It is crumbly, loose, and humus-like It has an earthy smell It contains no readily recognizable feedstock The pile has shrunk to about 1/3 of its original volume

Simple Tests to Ensure Compost Readiness Bag test: Compost left in a plastic bag should remain fresh-smelling after two days! Germination test: Make sure that seeds actually germinate in it!

Using Finished Compost Soil amendment – This is the main use of compost. – Mix evenly into soil at least 6 inches deep for annuals and 12 inches for shrubs. Add at least 30% by volume. – Do not add compost to tree planting sites!

Avoid Root-Bound Trees!

Fertilizers and Plant Nutrition

Essential Plant Nutrients Macronutrients – Required in relatively large amounts. Micronutrients – Required in small amounts. – Minor or trace elements.

Macronutrients Fall into one of three categories: – Non-Mineral Elements – Primary Nutrients – Secondary Nutrients

Non-Mineral Elements (C) Carbon (H) Hydrogen (O) Oxygen

Primary Nutrients (N) Nitrogen (P) Phosphorus (K) Potassium

Secondary Nutrients (Ca) Calcium (Mg) Magnesium (S) Sulfur

Micronutrients (Fe) Iron (Cu) Copper (Zn) Zinc (B) Boron (Mo) Molybdenum (Mn) Manganese (Cl) Chlorine

Function & Deficiency Symptoms of Nutrients

Nitrogen Function – Promotes growth of leaves and stems. – Gives dark green color and improves quality of foliage. – Necessary to develop cell proteins and chlorophyll.

Nitrogen Deficiency Symptoms – Sick, yellow-green color. – Short stems, small leaves, pale colored leaves and flowers. – Slow and dwarfed plant growth.

Phosphorus Functions – Stimulates early formation & growth of plants. – Provides for fast & vigorous growth and speeds maturity. – Stimulates flowering & seed development. – Necessary for the enzyme action of many plant processes.

Phosphorus Deficiency Symptoms – Decrease in growth. – Slow maturity. – Older leaves are purplish color.

Potassium Functions – Used to form carbohydrates & proteins. – Formation and transfer of starches, sugars, & oils. – Increases disease resistance, vigor, & hardiness.

Potassium Deficiency Symptoms – Mottled, spotted, streaked or curled leaves. – Scorches, burned, dead leaf tips & margins.

Potassium Deficiency Symptoms – Mottled, spotted, streaked or curled leaves. – Scorches, burned, dead leaf tips & margins.

Calcium Functions – Improves plant vigor. – Influences intake & synthesis of other plant nutrients. – Important part of cell walls.

Calcium Functions – Improves plant vigor. – Influences intake & synthesis of other plant nutrients. – Important part of cell walls.

Magnesium Functions – Influence the intake of other essential nutrients. – Helps make fats. – Assists in translocation of phosphorus & fats.

Magnesium Deficiency Symptoms – Interveinal chlorosis. (Yellowing of leaves between green veins) – Leaf tips curl or cup upward. – Slender, weak stems.

Sulfur Functions – Promotes root growth and vigorous vegetative growth. – Essential to protein formation.

Sulfur Deficiency Symptoms – Young leaves are light green with lighter color veins. – Yellow leaves and stunted growth.

Iron Functions – Essential for chlorophyll production. – Helps carry electrons to mix oxygen with other elements.

Iron Deficiency Symptoms – Mottled & interveinal chlorosis in young leaves. – Stunted growth & slender, short leaves.

Copper Functions – Helps in the use of iron. – Helps respiration.

Copper Deficiency Symptoms – Young leaves are small and permanently wilt. – Multiple buds at stem tips.

Zinc Functions – Plant metabolism. – Helps form growth hormones. – Reproduction.

Zinc Deficiency Symptoms – Retarded growth between nodes (rosetted) – New leaves are thick & small. – Spotted between veins, discolored veins.

Boron Functions – Affects water absorption by roots. – Translocation of sugars.

Boron Deficiency Symptoms – Short, thick stems tips. – Young leaves of terminal buds are light green at base. – Leaves become twisted & die.

Boron Deficiency Symptoms – Short, thick stems tips. – Young leaves of terminal buds are light green at base. – Leaves become twisted & die.

Manganese Functions – Plant metabolism. – Nitrogen transformation.

Manganese Deficiency Symptoms – Interveinal chlorosis. – Young leaves die.

Complete vs. Incomplete Fertilizers Complete Fertilizers – Contain all 3 primary nutrients (nitrogen, phosphorus, & potassium) Examples: – – –

Complete vs. Incomplete Fertilizers Incomplete Fertilizers – DO NOT have all 3 primary nutrients. Examples: – – –

Organic vs. Inorganic Fertilizers Organic Fertilizers – Come from plant or animal matter & contain carbon compounds. Examples: – Urea – Sludge – Animal Tankage

Organic vs. Inorganic Fertilizers Advantages of Organic Fertilizers – Slow release of nutrients. – Not easily leached from soil (less potential to result in water pollution). – Add organic components to soil.

Organic vs. Inorganic Fertilizers Disadvantages of Organic Fertilizers – Expensive – Low nutrient content – Take longer to show effects

■ Alfalfa Meal Average NPK analysis: ■ Blood Meal Average NPK analysis: ■ Bone Meal Average NPK analysis: Varies from about to about , also contains about 24 percent calcium. ■ Coffee Grounds Average NPK analysis: ■ Compost Average NPK analysis: to 4-4-4; about (25 percent organic matter). ■ Cottonseed Meal Average NPK analysis: N-P-K Content of Some Organic Products

■ Eggshells (adds calcium mostly) Average NPK analysis: About ■ Epsom Salts Average analysis: 10 percent magnesium, 13 percent sulfur. ■ Feather Meal Average analysis: Nitrogen 7 to 12 percent. ■ Fish Emulsion Average NPK analysis: 5-2-2, also contains sulfur. ■ Mushroom Compost Average NPK analysis: About ■ Soybean Meal Average NPK analysis: ■ Worm Castings Average NPK analysis:

Choosing a Fertilizer

General Rules Method used should be…. – Practical – Effective – Cost Efficient Method used affects nutrient availability for plant use. Fertilizer must be dissolved and reach plant roots.

Banding Placing a band of fertilizer about 2 inches to the sides & about 2 inches below seed depth. Do NOT place below seeds because fertilizer will burn roots.

Sidedressing Placing a band of fertilizer near the soil surface and to the sides after seedlings emerge from the soil.

Topdressing Mixing fertilizer uniformly into the top one to two inches of growing media around the plant.

Perforating Placing fertilizer in 12 – 18” holes drilled 18 – 24” around the canopy drip line of fruit trees. Cover the holes & the fertilizer slowly dissolves.

Broadcasting Spreading fertilizer to cover the entire production area.

How much Fertilizer do Landscape and Edible Plants Need? Most vegetables: -0.5 to 2 lbs of nitrogen per 100 feet of row. -Ammonium phosphate ( ) is a good choice if compost hasn’t been worked into the soil -When seedlings are 3-4” reapply

Before planting fruit trees place one of the following in the bottom of the planting hole and cover with 1-2 inches of soil: 1 lb treble super phosphate (0-45-0) 2 lb single super phosphate (0-25-0) 2 pounds fine phosphate rock* 3 ½ pounds bone meal* 7 to 8 pounds well composted/aged manure* * Blend with backfill to avoid burning the roots. Plant the tree. Then, spread an equal amount of one of the above on the soil surface around the tree.

Nitrogen Application – Fruit Trees Amount of nitrogen to Apply Per Tree Per Year Season Orange Juice Can Lbs. of Ammonium Sulfate Lbs. of Actual N 1st (after planting) ½ can (twice) nd 1 can (twice) rd3 cans th5 cans th7 cans th8 to 10 cans to 1.0

Landscape Tree Fertilization -Not more than.5 lb N per inch trunk circumference -OK to wait until minor symptoms develop

Lawn Fertilization Total: 4-5 lbs N/year -2-3 lbs N as ammonium sulfate -2-3 lbs N as a ratio fertilizer

Lawns: NPK Ratio twice a Year

Why Have Garden Soil Tested? Most Important Reasons: -To determine pH (too high can tie up micronutrients) -To determine salt content (plant injury) Other Reasons: -To determine texture (sand, silt, clay) and water holding capacity (although you can do this easily yourself using a jar of water) - To determine nutrient content (too much or too little)

There is no Need to Test Levels of Nitrogen Since it is so Mobile! -Results will be invalid by the time you receive the results -Apply nitrogen based on MG Handbook recommendations for various types of plants

How to Conduct a Soil Test -Identify homogeneous areas of your yard -Collect between 6-10 soil samples within each area and mix them together thoroughly -Sample depth should be between 6” and 1’ depending on type of plant and root zone -Submit about 1 pint (2 cups) to a reputable soil testing lab

Tips -Avoid fertilizing or adding soil amendments just prior to testing -Make sure compost and other organic soil amendments are broken down and stable before their addition -Consider water quality as well. It may need to be tested

Tips (con’d) Most nutrient-related problems can be controlled simply by reducing pH and EC levels. - High pH (above 7.5) can tie up nutrients such as zinc, iron, and manganese. - Add elemental sulfur or fertilizer with nitrogen sulfate to reduce a high pH - Add organic matter to your soil or garden in raised beds amended with organic matter and/or peat

Refer to Table Below for Rates

Electrical Conductivity -Measures how easily an electrical current can pass through the soil -High EC value indicates high salt levels -Many plants are sensitive to salt contents as low as 3-4 dS/m. Most are sensitive to ECs above 8 dS/m -Salts include cations and anions that are essential plant nutrients (such as potassium and nitrate) as well non-essential elements such as sodium

High Levels of Sodium

A Few Very Salt-Sensitive Plants -Crape myrtle -Plum -Apple -Pear -Desert Willow

A Few Salt-Tolerant Plants -Honey locust -Honey Mesquite -Chilean mesquite -Salt Cedar -Salt grass

This Website Lists Salt Tolerances of Several Plants

How Can you Reduce Levels of Harmful Salts? -Leach below the root system (apply water slowly for several hours) -If high EC is due to sodium, apply gypsum to displace sodium with calcium (you still need to leach the sodium out though!)

The Michigan State University Soil Test Website Allows You to Type in Test Results (pH, nutrient levels, CEC, etc. for Specific Recommendations in Landscapes and Gardens Msusoiltest.com

Thank You! Janet Hartin (951)