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19 Cards in this Set
- Front
- Back
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What are the earths atmospheres two main gases? |
Nitrogen 76% Oxygen 21% |
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What is causing an increase in CO2? |
Deforestation and the combustion of fossil fuels |
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What are the 3 main benefits of supplemental CO2? |
1. Higher Crop quality 2. Shorter crop time 3. Increased yields |
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How does a glass house differ from a poly house in the way of supplemental Co2? |
Glass houses breath so this allows a greater exchange of fresh air which replenishes the greenhouse CO2 levels. There is less chance of CO2 deficiency |
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What is one negative to using supplemental CO2 in glass houses? |
It can be more easily lost from glass house to the outside Glass houses need a higher rate of CO2 than poly houses |
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What are 3 ways that weather can affect CO2 levels? |
1. Wind will increase natural air exchange 2. Light- As natural light intensity or duration increase the rate of photosynthesis increases which uses CO2 more quickly 3. Different temperatures like cold temps will cause the vents to close and there will be less CO2 replenishment |
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How does Light affect CO2 levels? |
Plants use CO2 more efficiently under higher light conditions so therefore enrichment should be added during photosynthetic lighting. No advantages of adding CO2 at night |
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What are the three possible ways to provide CO2? |
1. Infiltration of fresh air from outside 2. Respiration by plants 3. Decomposition of organic material in the soil |
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Conditions which reduce CO 2 level? |
1. Consumption by plants 2. Natural air exchange 3. Weather 4. Media |
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Describe Open Flame units as CO2 generators? |
They are small capacity CO2 generators Connected to a fuel source Released by diffusion through the hosue |
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Describe Forced- air units as CO2 generators? |
Have a fan which blows the combustion horizontally above the crop |
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What is the main disadvantage to using Flue gas as source of CO2? |
Potential for pollution if incomplete combustion happens |
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Advantages of liquid CO2? |
- Mor precise control of rates and concentration - Less impurities that come from combustion flue gas |
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Main disadvantage of Liquid CO2? |
High operating costs |
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How much CO2 do most corps use? |
800-1200 ppm |
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CO2 treatment is usually controlled by...... |
Timelock. It should begin one hour before sunrise and should end one hour before sunset |
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What are the 4 limitations of CO2 enrichment? |
1. Ventilation cycles - During high ventilation periods more CO2 is lost therefore should be turned off 2. Crop response- If the crop does improve due to the CO2 then all other aspects such as water, nutrition, light etc need to be increased to keep the plant balanced so it doesn't get stress. 3. Lack of research 4. Energy Conservation |
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What are some air pollutants that can come from CO2 enrichment? |
1. Ethylene 2. Sulphur Dioxide 3. Nitrogen Oxide 4. Propylene 5. Carbon Dioxide |
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What are some computer controls of CO2 enrichment? |
1. Time control (dosage can be based on time) 2. Light Control (light threshold setting where CO2 will come on when light level is greater than setting) 3. Concentration (Based on the amount of CO2 in the greenhouse) 4. Dosage control (Used when vents are closed) 5. Cycle control |
