Understanding Properties of Growing Media Lesson 1 Vermiculite>>>>>

Next Generation Science/Common Core Standards Addressed! HS‐LS2‐3. Construct and revise an explanation based on evidence for the cycling of matter and flow of energy in aerobic and anaerobic conditions. [Clarification Statement: Emphasis is on conceptual understanding of the role of aerobic and anaerobic respiration in different environments.] [Assessment Boundary: Assessment does not include the specific chemical processes of either aerobic or anaerobic respiration.] WHST.9‐12.9 Draw evidence from informational texts to support analysis, reflection, and research. (HS‐LS1‐1) HSSIC.A.1Understand statistics as a process for making inferences about population parameters based on a random sample from that population. (HS‐LS2‐6)

TERMS Aeration – the presence of air Growing medium – material used for plant growth Hydroponics – growing plants w/o “soil” Leach – to remove by percolation Pore spaces – voids for water or air holding Soil – outer layer of the earth suitable for plants Soilless medium – sterile product/s used for plants

Bell Work! 1. Identify the types of growing media. 2. Describe the functions of growing media. 3. Explain the relationship between growing media and plant growth. 4. Why is a good growing media made up of a variety of components?

Interest Approach What makes a great basketball team? 5 or more members that work well together. At least 1 who can score points from 20’ +. At least 1 who can be used inside the key. 1 or more who can control the ball. 1 or more to push the ball inside. Each player has their strengths!

Interest Approach What makes a great growing medium? Several components that work well together 1 or more that hold water. 1 or more that hold air. 1 or more sources of nutrients. 1 or more to help defend against pest. Components that are sterilized.

Interest Approach Which Makes the Best Growing Medium? Sand Peat Moss Field Soil Vermiculite Pearlite Water Gravel or a mixture! Find out from the class what they feel is the best medium. Question where “soil” is used for floriculture? Ask how they have purchased plants and what the medium was? Lead a discussion on what each sample contains that allows it to be used as a growing media.

What are the types of growing media used in floriculture production? Is “soil” used? Soil – the earth’s outer crust is full of life! Bacteria Fungi Invertebrates Yes – we use field grown plants for some production. Outdoor production has problems of its own. Bacteria – fungi - …. Cut flower production can occur outside of a greenhouse. Some greenhouse production is in field soil.

What are the negatives of using “SOIL” for containers? Unknown history of: Pesticides pH Fertility level High shrink / swell Soil shrinks as it dries – forming cracks Higher disease probability Container medium must be sterile!! Container medium must be spongy! Can field soil be sterilized? Fumigants and steam can kill all life in the soil.

So what media should you use? Sand? Dries to quickly. Peat moss? Dries to slowly. Choir? Hard to get wetted. Water? To little air. Pearlite? To much air. Vermiculite? Pricey. Potting soil mixes? Just right. Many materials can be used – each has its own pitfalls Choir – coconut fibers that are hollow All material can be reduced in size and thereby its properties for a media In general, a combo of materials is used.

The 3 basic types of media! Soil – natural layer of the earth that supports life. Soilless – any material for growing plants not containing topsoil. Hydroponics – plants grown primarily in nutrient solution.

What are the functions of the growing media? Must provide AIR. Must provide WATER. Must provide Nutrients. Must provide ANCHORE / SUPPORT. Aeration (the presence of oxygen) is another important characteristic of growing medium. Plants need oxygen in order to make their own food. Plant roots also need to be able to breathe. The oxygen in the media is located in the pore spaces between the particles of the of media. The pore spaces are the air holes between the particles. Growing media must also be able to hold moisture for plant growth. Along the same lines, the media must also allow for drainage so the roots don’t starve or rot. Growing medium needs to provide nutrients to the plants. The nutrients are needed by the plants for growth and flower and fruit production. Growing media must also provide a place for the roots to anchor themselves. Plant roots are fragile and are crucial to a plant’s successful growth. If the media helps hold the plants, the plant is less likely to fall over or move about, ripping the root system.

What effect does growing media have on plant growth? Supplying Nutrients Some media cannot hold essential elements for plants. Nutrients are leached out to rapidly. Stressed plants are prone to disease and insect damage – increasing loss. Reduced growth = lower returns Choosing the right growing media for floriculture crops is very important. The media can affect the amount of nutrients that are available for the plants, the presence of water, and the ease of growth plants.

What effect does growing media have on plant growth? Supplying Air As air is reduced, plant stress increases. Roots need oxygen and water – both in moderation. Increasing stress increases pest susceptibility and profit loss The ability of the growing media to drain water is very important for plant growth. Plant roots need oxygen to function properly and if the growing media is saturated with water, the plant roots will die due to lack of oxygen. The roots may also rot. Excess water in the growing media can also lead to insect problems.

Necrotic line patterns in the foliage of a cyclamen affected by impatiens necrotic spot tospovirus (INSV).

What effect does growing media have on plant growth? Uniformity Large scale production demands that all plants perform equally. This is only possible if all plants get equal inputs from a uniform media. In the production of floriculture crops, it is important to use a growing medium that is uniform. With a uniform mix, watering, fertilizing, and transplanting schedules can be developed in order to insure even growth of the crop.

Review

What are the 3 types of media? Soil define Soilless Hydroponics

What are the functions of growing media? Supply Air. Why? Supply water. Supply nutrients. Supply support / anchor.

Why is it important for media to: Supply nutrients? Increase healthy plants,growth and returns. Supply air? Reduce diseases and increase profit. Supply uniformity? Plant schedules require uniform plant growth!

The End! Peat Bog!

The End! Mud Bog!