Media, Nutrients, & FertilizersChapter 6 - Textbook pages …

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?

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)

QuickTime™ and a decompressor

are needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

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

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

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

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)

QuickTime™ and a decompressor

are needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

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:

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

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

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

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!!!