1. Media, Nutrients, & Fertilizers
Chapter 6 - Textbook pages …

2. Essential Questions: What are the different types of growing media?
What are the components of soil?
What are the components of a soilless mix?
What effect does growing media have on plant growth?
How do plants use soil?

3. What are the different types of growing media?
There are a number of substances that allow plants to grow:
Soil - the outer portion of the Earth’s crust that supports plant growth
Soilless medium - one that contains no topsoil
Hydroponic solution - a nutrient solution for plants to grow in (plants can be supported in gravel or sand or the roots can be left bare)

4. What are the components of soil?
Soils - characterized by the amount of mineral matter found in them
Mineral matter (45%) is inorganic or non-living substances that form soil.
Organic matter (5%) partially decomposed animal and plant matter
Air (25%) part of the pore space in the soil
Water (25%) also part of the pore space

5. What are the components of soil?
Soils - characterized by the amount of mineral matter found in them
Mineral matter (45%)
Sand - the largest soil particle
Silt - smaller than sand, found near rivers
Clay - smallest particle, holds moisture well but cracks and forms hard clumps when dry
Loam - equal amounts of sand, silt, and clay

6. What are the components of a soilless mix?
Soil is not used very often for floriculture - it can be heavy and full of undesirable weed seeds and insects. A soilless mix is a combination or organic and inorganic substances; it does not contain topsoil

7. What are the components of a soilless mix?
Common components in a soilless mix:
Peat moss - plant material that has great moisture and nutrient holding capacity
Perlite - white in color and comes from heat-treated lava rock (used to aerate the soil)
Vermiculite - comes from the mineral mica and is shiny brown in color (used in media for seed germination)

8. What effect does growing media have on plant growth?
Choosing the right growing media is very important. The media can affect the amount of nutrients available for the plant.
Compare & contrast the use of soil versus a soilless mix:

9. What effect does growing media have on plant growth?
Advantages of a soilless mix:
The mix is uniform; it does not vary in components, texture, or nutrients
The mix is sterile; it does not have disease organisms, insects, or weed seeds
Can be manipulated to improve drainage and moisture holding capacity
A grower can personally mix the components for a particular crop
Easier to ship and move because they are lightweight
Advantages: sterile, uniform mix; easier to move and manipulate; can be personalized

10. What effect does growing media have on plant growth?
Disadvantages of a soilless mix:
Fertilizers often need to be added more frequently
The wind can blow dry pots over because the mix is very light
Sometimes difficult to transplant a plant from a soil mix to a soilless one (roots will often not grow in the new media and the plant will die)
Disadvantages: need more fertilizers; does not secure pots; difficult to transplant

11. How do plants use soil?
Plants depend on soil to provide four basic needs:
1. Anchorage - soil acts to provide a firm support as roots grow throughout the soil
2. Water - soil provides nearly all of the water used by plants (water is absorbed through the plants’ roots)
3. Oxygen - plants release oxygen through photosynthesis but consume oxygen during respiration; good soil aeration allows for oxygen transfer
4. Nutrients - of the 16 nutrients considered to be essential for plant growth, 13 are obtained from the soil

12. I’m still missing a lot of previous work from MANY of you!!!
Homework
CER summary…. (as always)
Write a comparison paper on the effects of different media on plant growth
At least three paragraphs (introduction, supporting evidence, conclusion)
Due next Monday
Questions?
I’m still missing a lot of previous work from MANY of you!!!