SOILS & FERTILIZERS Larry G. Campbell WVU-Harrison County Extension Agent WVU Assistant Professor

What is Soil? Soil is a combination of weathered rock fragments, newly formed clay minerals, and the decaying remains of plants and animals. Air, water, and microorganisms are also a part of soil.

Soil Layers Surface soil: -Upper layer of soil that has the heaviest concentration of organic matter. -Usually the most fertile soil layer and the part of the soil with the greatest concentration of plant roots. Subsoil: -Layer that usually has a firmer and finer texture than surface soil and has a lower organic content. -Storage space for water and plant nutrients.

Soil Layers Parent material: -Decomposed rock. -Fractured rock. -Influences the soil’s texture, natural fertility, rate of formation, acidity, and depth.

Mineral vs. Organic Mineral Soils = less than 20% organic matter. -1%-5% are most common in surface soils. Organic Soils = 20% or greater organic matter. -Eg. Peat soils.

WV Soils Most WV soils are mineral. Sandstone, shale, and limestone sedimentary rocks have influenced WV soils the most. Many WV soils have large amounts of rock fragments.

Soil Components Mineral -Many different kinds and sizes of particles that originate from the parent material. Organic Water & Air -The ideal surface soil has 50% solid material and 50% pore space. -Ideally the pore space contains about 25% air and 25% water.

Organic Matter Dead: -Remains of plants and animals. Really dead: -”Humus” which is the portion of organic matter that remains after most decomposition has taken place and soil nutrients. Living: Various soil organisms.

Soil Organisms Range in size from the tiniest one-celled bacteria to the visible earthworms and other insects. They feed on organic compounds in the soil and help to decompose them. They fix nitrogen from the atmosphere making it available to plants. Enhance soil aggregation and porosity. Prey on plant pests and are food for other insects and animals.

Bacteria Tiny one-celled organisms. A teaspoon of good soil contains between 100 million & 1 billion bacteria. Most are decomposers, some are nitrogen-fixing, some are pathogenic, and others can break down pollutants.

Fungi Fungi are microscopic cells that usually grow as long threads or strands called hyphae, which push their way between soil particles, roots, and rocks. Mushrooms are the fruiting structures of fungi. They are decomposers, help plants absorb nutrients, and can both cause and control disease.

Protozoa Single-celled animals that feed on bacteria, other protozoa, soluble organic matter, and fungi. Several times larger than bacteria—up to 1/50 of an inch. Ciliates, Amoebae, & flagellates. Mineralize nutrients for plants, regulate bacteria populations, control disease, and are food for other soil organisms.

Nematodes Non-segmented worms typically 1/500 of an inch in diameter & 1/20 of an inch long. Bacterial feeders, fungal feeders, predatory, omnivores, and root feeders.

Arthropods Arthropods get their name from jointed (arthros) legs (podos). They are invertebrates which means they have no backbone and have an exoskeleton. Range in size from microscopic to several inches. Several thousand species may live in a square mile of forest soil.

Shredders: chew up dead plant matter as they eat bacteria and fungi on the surface of plant matter. Examples are millipedes, sowbugs, and certain mites.

Predators: Include centipedes, spiders, ground-beetles, scorpions, pseudoscorpions, ants, and some mites.

Herbivores: Include root feeders such as symphylans, mole-crickets, cicadas, and root worms.

Fungal Feeders: Arthropods that graze on fungi which include springtails, some mites, and silverfish. Responsible for a large fraction of nutrients available to plants.

Earthworms Major decomposers of dead and decomposing organic matter. Fragment organic matter and recycle the nutrients. 7,000 species in the world. Range in size from an inch to 2 yards. Usually an indicator of soil health.

Physical Properties of Soil Color Texture Structure Internal drainage Depth

Color Caused by organic content, drainage conditions, and degree of oxidation or weathering. Surface soils: -Dark indicates a high organic content, but can originate from parent material. - Light or pale soils generally indicate highly leached conditions. Subsoil: -Red & brown show free movement of air & water. Show degree of iron oxidation. -Grey & yellow indicate slow internal drainage.

Texture Texture is the relative distribution of different sized soil mineral particles less than 2.0 mm in diameter. It depends on the amounts of sand, silt, and clay present.

Texture Sand: Mineral particles of soil greater than.05 mm in diameter up to 2.0 mm. Silt:.002 mm to.05 mm in diameter. Feels floury when dry and is not slick or sticky when wet. Clay: Less than.002 mm. Slick and sticky when wet. Will hold the form into which it is molded. Loam: Contains 7-27 % clay, % silt, and 52 % sand.

Main WV Surface Soil Classes Silt Loam: Silt dominates & feels floury. Loam: Equal in sand, silt, and clay. Silty Clay Loam: Somewhat slick or sticky when wet, but silt is the dominate part. Sandy Loam: Feels sandy, but contains silt & some clay which holds soil together when moist. Clay: Clay dominates. Hard when dry & sticky when wet.

Structure Refers to how soil particles are grouped or “aggregated” together. Surface soil is usually “granular.” Granular: Porous granules held together by organic matter and some clay. Granular soil allows for good air and water movement and strong root development. “Platy” soils have thin layers that are closely packed together which does not allow for good plant growth.

Internal Drainage Slope is a major factor. Red and yellowish red indicate well- drained soils. Wet soils are gray, drab, or mixed.

Depth The vertical distance from the surface to a layer that essentially stops the downward growth of plant roots. Very shallow: less than 10”. Shallow: 10-20”. Moderately deep: 20-36”. Deep: 36-60”. Very deep: 60”.

Soil Structure Improvement Compost Cover Crop Photo by L.G CampbellPhoto by L.G. Campbell

Plant Nutrients Plus N & S

pH pH is the measure of the hydrogen (acid-forming) ion activity of soil. It indicates the degree of acidy or alkalinity. 6.5 is 10 times more acid than 7.5 High acid soils can concentrate minerals at toxic levels to plants or make minerals unavailable.

Fertilizers Labeled with 3 numbers. Numbers give the % by weight of nitrogen (N), phosphorous (P), & potassium (K). Do not add up to 100% because there are other materials such as conditioners, absorbents, and fillers mixed in too.

Fertilizers Inorganic: ammonium sulfate, superphosphate, and potassium chloride. Synthetic Organic : Urea. Natural Organic: Manures, bone meal, fish emulsion, green manures.

Applying Fertilizers Recommendations are generally per 1,000 sq. ft. Example: 2 lbs N per 1,000 sq. ft. using (ammonium nitrate) & you have 4,000 sq. ft of garden. -2 x 4 = 8 of N needed. -8/33 (%N) x 100= 25 lbs of fertilizer.

Fertilizer Example 2 Garden: 1,000 sq. ft. Recommendation: 2 lbs N per 1,000 sq. ft. Fertilizer: x 1= 2 lbs N. 2/10 (% N) x 100 = 20 lbs

This PowerPoint program was assembled by Larry G. Campbell, WVU-Harrison County Extension Agent and WVU Assistant Professor. In addition to this author’s material, some photographs, illustrations, and supporting materials were assembled from various sources publicly available on the Internet. The information was gathered over a period of time and from sources too numerous to list individually. The author would like to acknowledge the assistance of these web sites and publicly express his sincere appreciation for the assistance. This program was assembled solely for educational purposes and primarily for use with statewide WV Master Gardener training programs. The author did not nor will ever receive financial compensation for the preparation of this program. The program may be copied and distributed in parts or in its entirety for educational purposes. If any part of this presentation is distributed, the efforts of Mr. Campbell in assembling the materials must be recognized. The distributor may not receive any financial compensation for this service. Larry G. Campbell WVU-Harrison County Extension Agent and WVU Assistant Professor WVU-Harrison County Extension Office 301 West Main Street Room 507 Courthouse Clarksburg, WV (304)