Soil in the Vegetable Garden: Its’ characteristics, preparation & management Mitchell Mote Extension Agent UT / TSU Extension Rutherford County

An introduction to how soil is formed and the various components in soil

GENERAL SOIL CHARACTERISTICS

Introduction y

What is Soil? ◦ the basic material of the gardener’s art ◦ has some characteristics of it’s parent material p ◦ not “dirt” (dirt is soil out of place)

Desirable soil characteristics The abilityy to supply pp y the necessaryy elements to plants in adequate quantities when needed (fertility) ( y) y Deep enough to insure adequate rooting for p plant stabilityy and pproduction y Stability: resist washing or blowing away y

The Formation of Soil y

y

y

Soil is formed over many years by the physical or chemical weathering of rock. Parent material refers to those rocks or deposits from which a soil develops. Deposits from wind and water also influence soil development

Soil Profile Most soils M il are arranged in 3 distinct l layers or hhorizons. i y The principle horizons are collectively called the soil profile. y

A = Topsoil

B = Subsoil

C = Parent Matter

The Formation of Soil y

The USDA Natural Resources Conservation Service lists 8 Major Land Resource Areas in Tennessee

Nashville or Central Basin (that’s us) The Nashville or Central Basin is predominately hilly and steep with widely scattered tracts of rollingg land y Soils range from shallow to deep over rock y Pasture and forest occupy the largest acreage y

Soil Composition (Of a Good Soil)

y y y y

Water & Air - 50% (by volume) Soil Mineral Matter - 48.5% (¨) Livingg Organisms g - .5% ((¨)) Organic Matter - 1% (¨)

Water & Air Saturation

Fi ld Capacity Field C it

Permanent Wilting Point

Living Organisms

.5%

Organic Matter (OM) Enhances development of structure. structure Stabilizes soil structure. structure Source of nutrients

(OM contains 5% N and 0.5% P & S)

Large nutrient and water holding capacity

1% Eatt M E More Chicken

Soil Physical Properties – difficult to change y y y y y y y y

Landscape Position Slope Rooting Depth Color D i Drainage Presence of Rock Fragments Soil Texture Odor – may be a chemical property

Soil Texture y

y y

y

The mineral portion of the soil is made up of a mixture of 3 base particles; sand, silt and clay. Their proportions in the soil determine texture They differ in size and composition Sand and silt are larger; mostly crushed quartz, f ld feldspar, mica, i hhornblende bl d & augite i (silt ( il can’t ’ bbe seen without a microscope) Clay is much smaller, smaller particles not visible without extreme magnification; composed mostly of minerals formed by the chemical breakdown of sand and silt

Soil Texture y

The Size of Soil Particles

Medium Silt

Fine Sand

Coarse Clay

Soil Texture Loam- a mixture of sand, silt and clay in relatively e at ve y equa equal co concentration ce t at o that’s t at s considered ideal for agricultural uses. y Soil texture classifications are based on the percentages of sand, silt and clay y 12 texture classes have been established y

100 90

Percent Clay

Soil

80

10 Percent 20 Silt

70

30 40

60

Textural

50

50

Triangle g

60

40 30

70 80 90

20 10

100 100

90 80 70 60

50 40 30

Percent Sand

20 10

Soil Texture 3 soil textural groups; can be determined with the finger test y Finger g Test- wet soil sample p to the consistency of putty; form a ½”-¾” diameter ball; press the ball between thumb/finger & try to form a ribbon y Coarse texture- won’t form a ribbon y Medium texture- short ribbon, breaks easily y Fine texture- ribbon holds together well y

Importance of Soil Texture y

Soil texture affects: ◦ ◦ ◦ ◦ ◦ ◦

Water and nutrient holding capacity Water infiltration rate Water movement in the soil p Root penetration Ease of tillage More

Available Water Holding Capacity (AWHC) of Soil Textural Groups Texture off Soil S i Coarse

Average AWHC C (inches/inch of soil) 0 05 0.05

Medium

0.20

Fine

0.15

Soil Chemical Properties – more readily manipulated

Soil Chemical Properties Two chemical p properties p are easyy to measure accurately and are fairly easy to manipulate: p y pH y Nutrient levels

Essential Plant Nutrients ((18)) Micronutrients: Non-Mineral: Non Mineral: Carbon - C H d Hydrogen -H Oxygen - O

Primary or Macronutrients: Nitrogen - N Phosphorus - P Potassium - K

Zinc - Zn Chlorine - Cl Boron - B Molybdenum - Mo Copper - Cu

Secondary:

Iron - Fe

Calcium - Ca

Manganese – Mn

Magnesium g - Mg g

Cobalt – CO

Sulfur - S

Nickel - Ni

Function of Elements y y

NITROGEN – Promotes rapid vegetative growth PHOSPHORUS – Stimulates root growth& blooming & aids

i seed in d formation. f i y POTASSIUM - Increase vigor & disease resistance. Increase stalk & straw strength. Increase grain & seed quality. y CALCIUM - Improves root formation, straw stiffness and vigor. y MAGNESIUM - Helps uptake of other elements & aids chlorophyll formation, phosphorus metabolism.

Elements functions cont. cont y

SULFUR - Amino acids, vitamins. Promotes dark green color.

y

Boron – Aids carbohydrate transport and cell division.

Copper – Enzymes, light reactions. y Iron – Chlorophyll formation. y Manganese g – Oxidation-reduction reactions. y

y

Hasten germination and maturation. Zinc – Auxins, enzymes.

Elements functions cont. cont Molybdenum y – Aids nitrogen g fixation and nitrate assimilation. y Coba Cobaltt – Essential sse t a for o nitrogen t oge fixation. at o . y Nickel – Grain filling, seed viability. y Chlorine – Water use. use y Oxygen – Hydrogen – Carbon are compounds d off mostt plants. l t y

Soil pH Soil ppH refers to the amount of hydrogen y g (H) ions or acidity found in soils. y Acid c levels eve s increase c ease as basic bas c nutrients ut e ts (Ca, Mg, K) are replaced from the soil by y g hydrogen y Basic nutrients are removed by plants, leached or eroded leached, y Acid forming (N) fertilizers increase acid levels y

Soil pH The pH scale ranges from 0-14; most TN soils range from 4.5-7.5 y 7 is neutral; 7 is basic y Nutrient availability is directly affected by pH. H y

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ________________________________________ ACID/SOUR

ALKALINE/SWEET

Soil pH and Its Effects on Nutrient Availability

An introduction to the few things we can do to enhance a soils’ productivity

BASIC SOIL MANAGEMENT

It s difficult to plot a course for a It’s journey if you don’t know where you’re ’ starting t ti point i t iis. It’s equally difficult to effectively manage your garden’s garden s soil if you don’t have some basic information about it to begin with.

Soil Testing A way to measure the soil’s soil s chemical properties that we can manipulate y “Don’t Don t Guess, Guess Soil Test! Test!” y

◦ A basic soil test can be conducted through your county Extension office. office ◦ Charge: $7/sample (for basic soil test) ◦ Takes about 2 weeks to receive the results. results ◦ A basic soil test will indicate the pH value, Phosphorus (P) and Potassium (K) content, content Calcium (C) and Magnesium (Mg) content

S il Testing Soil T ti y

When to sample: ◦ Soils can be analyzed at any time of the year, however fall is a desirable time because: x Fields are drier and more accessible and the lab is not as busy. (*Soil samples must be dry when submitted to the lab.) x Testing in fall allows recommended rates of lime to be applied well in advance of spring planting (giving it a chance to work before planting)

S il Testing Soil T ti y

H How Of Often: ◦ Before planting a new garden or landscape area; then: h x Lawns/Gardens/Ornamental beds—every 3 – 5 years or if you suspect a problem. problem

Soil Sampling for a Good Soil Test y

What is a ggood soil test? ◦ One that is accurate!

y

How do you insure a good soil test? ◦ Collect a representative sample!

Soil S il Sampling Sam lin for f raG Good d SSoilil Test y

Tools Needed: ◦ A soil probe, shovel or spade ◦ Bucket ◦ Soil test form ◦ Soil sample box

Soil S il Sampling Sam lin for f raG Good d SSoilil Test y

For lawns and gardens, sub-samples should be collected at random from 8-12 locations. ◦ Areas of contrasting soils, problem spots or portions of the field where crop response is significantly different should be sampled separately. separately

Sample to a depth of 6” y Place each sub sub-sample sample in the bucket y Mix sub-samples well when they’re all collected; remove plant material & other debris; pull out about a cup to submit to the lab for testing y

Soil Sampling for a Good Soil Test y

Properly p y Select the Sampling p g Area. ◦ The area should not exceed 10 acres. ◦ Areas of contrasting soils, problem spots, etc. should b sampled be l d separately l if possible. ibl

X

Collect Adequate Sub Sub--samples

Collect Good Sub Sub--samples Uniform cores are important!

What About Sampling Raised and Other Beds? y

That’s a ggood question, q let’s talk about it!

Additional Steps to a Good Soil Test Fill out the information sheet accuratelyy (look at your example now) y For o each eac sample sa p e listed ste in the t e left e t column, co u , you may request recommendations for up p to 4 crops y Use crop codes listed on the back of info sheet (if yours isn isn’tt there there, write it in & be specific that it’s for a garden) y Info on sample boxes should correspond to the info sheet y

Let’s look at a soil test report and try y to interpret p it!

Wh t if pH What H Needs N d to t be b Adjusted? Adj t d? ◦ Various lime sources are used to raise soil pH when it falls below the recommended ranges ◦ Most common and economical in TN is agricultural limestone; can be calcitic (Ca) or dolomitic (Ca, Mg) ◦ UT recommends using elemental sulfur to adjust soil pH downward (to more acid range) when it is above the recommended ranges. ranges (Iron sulfate and aluminum sulfate can also be used.)

ADJUSTING THE SOIL PH LEVEL y

y

Apply lime to reduce soil acidity. Use no more than 50 lbs. per 1,000 sq. ft. per application. If more is needed, make split applications li ti 6 months th apart. t EExpectt llong adjustment period. Apply sulfur to increase soil acidity. acidity Use 2 lbs. lbs per 1,000 sq. ft. for each 0.1 unit change in the pH level. Apply 3 months before planting. Expect extremely short adjustment period. 1/3 more

needed on fine textured soil;; 1/3 less on coarse textured.

Now let’s feed the plants by adding fertilizer

Fertilizer Materials y y y

Complete p vs. Incomplete p Fertilizer Slow Release vs. Quick Release Fertilizers Organic Fertilizer

Understanding a Fertilizer Bag/Label y

Fertilizer Materials: ◦ The analysis on the bag refers to how much of each nutrient there is in that particular fertilizer, expressed as a percentage. ◦ All fertilizers are labeled with 3 numbers that represent the % of nitrogen (N), phosphorus (expressed as P₂O₅) and Potassium (K₂0). ◦ Simply Si l put, the h numbers b represent N N, P, PK

Fertilizer Analysis y

A fertilizer bagg should list: ◦ Percentages of: x N x P2O5 x K2O ◦ Sources of Nutrients x Urea or Ammonium Nitrate x Triple Super Phosphate x Muriate of Potash ◦ Amount (wt.) of Fertilizer

y Complete Fertilizer Fertili er: ◦ A fertilizer which contains N, P & K (the primary nutrients) ◦ Common examples are: 6-12-12, 10-10-10, 12-12-12,, 15-15-15 etc. y Incomplete Fertilizers: ◦ Will be missing one or more of the primary nutrients. ◦ Examples: 34-0-0 (ammonium nitrate), 46-0-0 (Urea), 18-46-0 (diammonium phosphate), 0-0-60 (muriate of potash) etc.

y

Slow Release Fertilizers: ◦ Contain one or more essential nutrients (usually N) which are released over an extended time (several weeks or more) ◦ Advantages include: fewer applications, applications low burn potential. potential ◦ Disadvantages include: delayed plant response ◦ Examples include sulfur coated urea (SCU), polymer coated urea (PCU), (PCU) and d many more

y

Quick Release Fertilizers: ◦ Highly water soluble, nutrients are released and become readily available to the plants quickly ◦ Advantages Ad t iinclude: l d quick i k response bby th the plant l t ◦ Disadvantages include: greater burn potential, may have to apply more frequently ◦ Examples include ammonium nitrate and many more

y Organic fertilizers: the nutrients contained in the product are derived solely from the remains of a once-living organism; usually not very nutrient i dense d x Examples: cotton-seed meal, blood meal, bone meal

◦ Inorganic I i or synthetic th ti fertilizers f tili : nutrients contained in the product are derived from inorganic materials (minerals); normally very nutrient dense compared to organics x Examples: urea urea, 13-13-13 13-13-13, etc. etc

Methods for Applying Fertilizers Broadcastingg y Banding y Fertilization of Planted Area only y Side dressings y Foliar F li FFeeding di y

HOW SHOULD FERTILIZER BE SPREAD ? y

Gravity Flow

y

Centrifugal

y

Hand

We ve manipulated the soils’ We’ve soils chemical properties with f tili fertilizers and d liliming i materials, t i l but can we do anything y g about the physical properties?

Using Soil Conditioners The best materials to add to your soil are compost and manure. y The addition of this organic matter will: y

◦ ◦ ◦ ◦

Improve overall soil texture/structure Improve drainage Improve water holding capacity Provide some nutrients

Using Soil Conditioners y y

y

Well-rotted Well rotted animal manure is the very best material to use, but it can be difficult to obtain. Compost is the ideal way to return as much organic matter as possible back to the soil, followingg natures example. p All amendments should be well-rotted and dug into the top layer of soil. Avoid using organic matter that is “hot” or not decomposed (like fresh mulch, sawdust, or fresh manure) this material t i l can bburn your plants. l t

Using Soil Conditioners Horse Manure y Pig Manure y Sheep Manure y Chicken Manure y Alternatives include: y

◦ Spent p mushroom compost, p , composted p ppine bark, (composted anything), cotton-seed hulls, leaves, rotten saw dust

Typical Composition of Manures: Manures vary greatly in their content of fertilizing nutrients. The kind of feed used, the percentage and type of litter or bedding, the moisture content, and the age and degree of rotting or drying can all modifyy the composition. p In the case of the commercially y dried p pulverized manures, some nitrogen g is lost in the process. The following data is representative of typical analyses from widely scattered reports. Approximate Composition, Per Cent Pounds per Ton Moisture Nitrogen Phosphoric Acid Potash Fresh Manure with Normal Quality of Bedding or Litter Cow 86 11 3 10 Duck 61 22 29 10 Goose 67 22 11 10 Hen 73 22 18 10 Hog 87 11 6 9 Horse 80 13 5 10 Sheep 68 20 15 8 Steer or feed yard 75 12 7 11 Turkey 74 26 14 10 Dried Commercial Products Cow, East 10 42 63 61 West 16 18 15 31 Hen, East (with litter) 16 56 57 30 West (droppings) 8 83 63 31 (with litter) 13 41 37 23 Hog, West 10 45 42 20 Rabbit, West 6 45 27 16 Sheep, East 10 38 30 40 West 9 27 19 41 Stockyard, East 8 41 32 36 West 15 41 11 38

Using Soil Conditioners y

Green Manure Crops ◦ Are ggrown specifically p y to add organic g matter to beds that are empty for a period of time. gg g it into ◦ It is sown with the intention of digging the soil to provide organic matter and plant food. ◦ Turn the crops under about 6 weeks before planting to allow the organic material to breakdown.

Using Soil Conditioners y

Green Manure Crops p that act as nitrogen g fixers: ◦ Anyy legumeg winter vetch, red clover, crimson clover, etc

y

Green Manure Crops p that do not fix nitrogen: ◦ Buckwheat,, rye, y , mustard,, annual ryegrass, y g , wheat, etc.

Getting ready to plant and during the fallow season

SOIL PREPARATION

Choose a Good Location Vegetables g love the sun; your y garden g needs at least 7 hours of sunlight per day y Keep eep wate water drainage a age in mind (fast ( ast and a slow) y Deep soil allows deep rooting y Is it close to water? y Can C you see it easily? il ? y Others… y

Be Prepared to be Timely y y y y y y

Soil test early enough so needed pH adjustments can take place prior to planting Make sure tools and power equipment are ready to work when you are Turn green manure crops under at least 6 weeks k bbefore f planting l i Work in leaves, compost, etc in the fall B ld raised Build d beds b d or temporary ridges d in the h fall f ll You can’t control the weather

Working the Ground Avoid workingg when wet; workingg wet ground leads to clods and increases compaction; p raised beds helpp with this y Work as deeply as you can, at least the top p 6”. Deeper p cultivation encourages g deeper rooting y Tillers, Tillers tractors w/plows, w/plows spades, spades digging forks, etc. can all work well y

Working the Ground y

Thoroughly g y mix soil conditioners into the soil to avoid creating drainage issues

Raised Beds y

Raised beds have some advantages: g ◦ They typically dry out and warm up faster in the spring than the “flat” garden so they’re often ready to plant earlier ◦ Compaction can be reduced due to minimal foot traffic in the bed ◦ It’s more feasible to manipulate the physical characteristics h i i off soilil iin a bbed d than h in i a large l plot of ground

Raised Beds y

Raised beds have some disadvantages: g ◦ They require labor and money (for edging, etc.) to develop ◦ Not well suited to sprawling plants such as watermelons ◦ They dry out faster

Building Raised Beds: There are lots of options! Example: p y

y y y

Mark off bed area; fertilize and lime and cover the area with compost, shredded leaves or other OM Work material as deeply into soil as possible with spading fork or tiller Edge the bed- wood, blocks, etc Add soil/OM mix to finish filling the bed; soil/OM recipe: 50% existing soil, 25% aged manure, 25% compostt

Building Raised Beds Double Digging gg g Example: p y y

y

y

Mark off boundaries; use a spading fork to work the bed Dig a trench 1’-2’ wide & one fork length deep across the end of the bed; remove this soil to the far end of the bed Add lime lime, fertilizer and OM in the trench; use spading fork to loosen soil in bottom of trench to the depth of fork tines & work in material Move over & dig another trench beside the first, placing the loosened soil on top of the previous trench; add OM mix,, loosen soil and mix materials

Double Digging - continued Continue p process to end of the bed y Fill in the last trench with the soil from tthee first st y Edge the bed and DON’T walk on it! y You now have a bed that should have a deep rooting zone y A 180-pound 180 d person burned b d approx. 688 calories per hour of double digging! y

When the Season is Over – flat gardens or raised beds alike Plant ggreen manure cropp or… y Work in shredded leaves, etc y Prepare some beds or ridges for spring planting y Rest up up, it it’ss been a long year! y

Q Questions?? ti ??