Soil Review Taking Soil Samples Soils and You Soil Review Taking Soil Samples

Soils Define Soil Soil profile Soil structure Soil texture pH Properties Soil sample purpose Where do they go? When? Procedures Interpretation

What is soil? Top layer of the earth’s crust Renewable natural resource that supports life It takes thousands of years to make one inch of soil, naturally.

Soil Profile Layers are horizons Typical profile- O: organic, humus A:topsoil, fertile, organic B:subsoil C: parent material R: bed rock

Soil Structure How particles cluster together Granular is best for most plants Particle-Ped-Structure

What are the principle forms of soil structure? Platy Columnar Granular Prismatic Blocky Single Grained

What are the three grades of structured soils? Weak- peds are hard to distinguish Moderate- peds are visible and can be handled without breaking Strong- most of soil is formed into peds

Discuss the effects of soil structure on crop production? With good structure, roots can grow more easily. Water can drain and be stored. Nutrients can be harvested by plants- accessible.

What are the advantages of good soil structure? Good drainage Good air movement Less erosion

What are the results of poor structure? Poor drainage Less air movement Erosion Decreased plant growth

What are some causes of poor soil structure? Compaction- tractors, livestock, people Tilling wet or muddy fields

What can we do to create and maintain good structure? Use no-till more often Make fewer trips in the fields Do not till wet soil Rotate with fibrous rooted crops Cover crops

What is soil aeration? Soil aeration relates to the exchange of air in the soil with air from the atmosphere.

Define soil tilth. It is the physical condition of the soil as related to tillage, seedbed preparation, seedling emergence, and root penetration.

Soil Texture Size of particles Clayey-small, high WHC Loamy-about equal parts of sand, clay and silt (ideal) Sandy-large particles, low WHC

WHC This is known as water holding capacity The larger the particle the lower the WHC Sand doesn’t hold water, right!

What are the physical characters of the soil that determine its suitability for plant growth? Texture Consistence Structure Aeration Tilth Moisture

What does soil texture affect? Compaction Ease of tillage Drainage Water-holding capacity

What are three major constituents of mineral soil? Sand-2.0-.05 mm Silt- .05-.002 mm Clay- less than .002 mm

Soil Permeability The ability of soil to allow water to percolate or move through the soil This is impacted by soil size and WHC like sand, silt, or clay

Properties 50% solid 50% pore space 25% water 25%air

Soil Triangle

pH Ideal for most ornamental plants and lawn or turf grasses is 5.5-7.0

Changing pH To make a soil more acidic, lower pH Add sulfur Sulfur is acidic and will lower the pH

Changing pH To make a soil more alkaline (basic), increase pH Add lime Lime is alkaline will increase the pH

Pedology The study of soils A pedologist is a soil scientist Study soil science at a land grant university like NCSU or NC A & T

Taking Soil Samples Purpose-determine need for lime, nitrogen, phosphorus, and potassium Nutrient deficiencies determined Sent to specialized labs to determine drainage, contamination, insects, diseases

When to take a soil sample… Anytime Early enough to allow adequate time to implement lab recommendations Fall planting-take in spring Spring planting-take in fall

Procedures 1. Get soil sample information sheets and cartons. 2. Clean tools and containers. 3. Take one composite sample from each uniform area. 4. Take 10-15 small cores or slices from the large uniform area.

Procedures-continued 5. Take core of slices about 4”deep for lawns and 6”deep for fields 6. Mix the cores or slices together in a clean bucket and take a sample of about one pint

Procedures-continued 7. Complete the sample information sheet and carton information. 8. Draw a map and keep a record of where you sampled and sample numbers. 9. Include the info sheet with the carton and mail or take to lab

Interpretation of Soil Test Reports Report provides the results of analysis and suggests a fertilization program, lime application, and other treatments

Interpretation Actual nutrients available are reported in ppm and also in levels such as high, low, very low,very high, slightly acid to help the grower understand the report.

Interpretation The level of acidity or alkalinity is shown by the pH. 7.2 slightly alkaline 7.0 neutral 6.3 moderately acidic

Interpretation Need more help? Contact your local cooperative extension agent, agricultural education teacher or other knowledgeable people who work with soil test reports.

Erosion When water or wind takes particles of soil and moves them away This often leads to pollution Detrimental to the environment

Soil Conservation The practice of keeping or improving soil in an area

Soil Erosion and Conservation at WHS Now, let’s go see where we have erosion and we will figure out what we can do to solve the problem.