Objective 23.01 Describe horticultural soils and hydroponics, as well as the advantages and disadvantages of each.

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 Continuous-flow system 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?