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

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

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

4. 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

5. Composting

6. 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

7. Inorganic compounds
Do not contain carbon
usually sterile

8. 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

9. Vermiculite

10. Perlite

11. 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

12. Hydroponics
The process of growing plants without soil

13. 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

14. 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

15. Hydroponics at Epcot

16. Advantages of hydroponics
No soil and problems associated with soil
Easy to control nutrient content of plants

17. 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

18. What is the physical make up of soil?