Soil Properties Essential Standard 5.00- Explain the role of nutrients and fertilizers.

Objective 5.01 Discuss Horticulture soils

Soils and growing media Soils and growing media are made up of two types of materials Organic matter Inorganic compounds

Organic Matter Dead plant or animal tissue contains carbon usually has diseases or insects

Types of organic matter Compost bark-particles too large to use in seed germination media mulch-used to cover soil to help hold moisture and prevent weeds straw peat moss

Composting

Types of Organic Matter Sphagnum Sawdust-high carbon to nitrogen ratio makes nitrogen unavailable for plant use Wood shavings- high carbon to nitrogen ratio makes nitrogen unavailable for plant use

Inorganic compounds Do not contain carbon usually sterile

Types of inorganic compounds Soilless media-artificial soil Vermiculite-mica mineral matter used to start seeds and cuttings, helps hold moisture, has neutral pH Perlite-natural volcanic material that helps aeration and water-holding capacity

Vermiculite

Perlite

Advantages of horticultural soils Sterile. pH is neutral. Disease and weed free. It is good for starting disease sensitive seeds Tomato It is easy to control the nutrient content Improves crop uniformity. It is easy to create a horticulture soil for particular plant needs.

Disadvantages Expensive It is light weight

Carbon : Nitrogen Materials with a high carbon to nitrogen ratio Sawdust Wood shavings Makes nitrogen unavailable for plant use

Soil Profiles and Sampling

Objective 5.02 Discuss the soil profile and soil sampling for surface and subsurface layers

What is the physical make up of soil?

Soil Profile Layers of soil are called horizons O, A, B, C and R Horizons All soil profiles do not have the same number of levels or horizons NC has a minimum of A, B and C or R horizons.

O Horizon Rich soil found where a plant cover has been in place for an extended time Rich organic matter Dark in color Most fertile layer

A Horizon topsoil and most fertile if there is no O Horizon Lies just below O Horizon Home to earthworms and soil organisms Brown in color due to the organic matter in the soil

B Horizon Subsoil Clayey soil that has high mineral content Usually brown or reddish in color due to large amounts of clay

C Horizon and R Horizon C Horizon R Horizon Parent material Consists mainly of clumps of un-weathered rocks R Horizon Bed rock Cannot be dug by hand and very few roots can penetrate the bedrock

Soil Profile A Horizon B Horizon C Horizon

Soil Profile

Soil Structure How particles cluster together single loose grains (sandy) granular (silty soil; best for most plants because water is able to move as needed) Blocky or platy (clay soils)

Soil Structure Single Grain

Soil Structure Granular

Soil Structure Blocky

Soil Structure Platy

Soil Structure Massive

Soil Structure Soil structure is more important to producers who grow plants in natural soils Producers of container grown plants add ingredients to make growing media desirable

Soil Texture Size of particles Types of textures clayey loamy sandy silty

Clayey Texture Smallest sized particles Has a high water and nutrient holding capacity most common texture in western NC

Loamy texture About equal parts of sand, clay and silt Ideal texture for most non-container outside plants

Sandy texture Largest particles Low moisture-holding capacity Most common in eastern NC

Silty Medium sized particles Has good moisture and nutrient holding capacity

Soil pH Measurement of acidity or alkalinity (base) from 0 to 14 Acid-less than 0-6.9 Neutral - 7 Alkaline-more than 8-14 Most organic matter is acid Most artificial media is neutral Ideal pH for most gardens is 5.5 to 7.0 Can use lime to raise pH, use calcium or sulfur to lower pH

Physical Properties of Soils Permeability rate at which water moves through the soil Water holding capacity ability of a soil to hold water for plant use Porosity amount of air space between soil particles

Physical Properties of Soils 50% of soil should be pore space 25% water space 25% air space. 50% of soil should be soil particles 45% mineral matter 5% organic matter

Soil Makeup Water

Soil Sampling Soil sampling and testing is essential for an accurate fertilizer recommendation for growing plants.

Soil Sampling Procedures Create a visual grid of the area to be planted. For gardens and landscapes, take 5-10 sub-samples Sample before the growing season. Use a stainless steel soil-sampling probe. Take the surface sample to tillage depth about 4inches for lawns 6-8 inches for crops Mix the soil samples together.

Soil Sampling Procedures Remove any grass, rocks or other material besides soil. Avoid unusual spots Problem areas need to be sent in a separate box. Place soil samples in a box Obtain from the County Extension Office along with Soil Sample Information sheet Send the box and information to: Agronomic Division Soil Test Lab in Raleigh for a free soil test.

FFA Land Judging CDE