Soil Properties Explain the properties of soils and their relationship to plant growth.
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
pH Measurement of acidity or alkalinity from 0 to 14 Acid-less than 7.0 Alkaline-more than 7.0 Most organic matter is acid Most artificial media is neutral Ideal pH for most ornamental plants and lawn or turf grasses is 5.5 to 7.0
Hydroponics The process of growing plants without soil
Types of hydroponics Aggregate culture –using sand or gravel to support plant roots Water culture, solution culture, or nutriculture –plant roots grow in water containing dissolved nutrients
Types of hydroponics Aeroponics –plant roots hang in air and are misted regularly with a nutrient solution Continuous-flow system –nutrient solution flows constantly over plant roots –most commonly used for commercial production
Hydroponics at Epcot
Advantages of hydroponics No soil and problems associated with soil Easy to control nutrient content of plants
Disadvantages of hydroponics Plant support must be provided with strings, wires or stakes Water quality must be high Diseases spread through water More moisture or humidity in air to cause favorable environment for disease organisms More expensive
What is the physical make up of soil?
Soil Profile Layers of soil are called horizons Typical profile –A Horizon-topsoil most fertile most organic matter top or first layer –B Horizon-subsoil –C Horizon-bedrock
Soil Profile A Horizon B Horizon C Horizon
Soil Profile
Soil Structure How particles cluster together –single grain –granular (best for most plants) –blocky –platy –massive
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
Clayey Texture Small particles Has a high water-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 Large particles Low moisture-holding capacity Most common in eastern NC
Soil Makeup Water
FFA Land Judging CDE