Heat Transfer in the Grow Zone
Convection
Describe what the rhizosphere is.
100 Bonus: Describe the phyllosphere.
The rhizosphere is the part of the plant that is below the surface of the substrate.
100 Bonus: The phyllosphere is the part of the plant above the surface of the substrate.
Name two types of hydroponic irrigation systems.
100 Bonus: What type do we use in our farms?
Ebb and flow, NFT, deep water, shallow water, aeroponics, Dutch bucket, drip, Kratky
100 Bonus: Ebb and Flow
This element is the most essential for plant growth and is the only gaseous nutrient that we supplement.
100 Bonus: Name the compound of that element that is added to our grow zone.
Carbon
100 Bonus: Carbon dioxide
Describe the visual symptoms of an iron deficiency.
Chlorosis of new growth with uniform coloration and steady transition.
When water is added to the surface of leaves, the highest energy molecules escape the liquid water and enter the air column, thus leaving the rest of the water cooler. What is this method of heat transfer called?
Evaporation
Plants can signal the microbes in the rhizosphere using what substance?
The composition of this substance can change depending on the life stage of the plant, stress, and the mineral nutrient deficiencies the plant is experiencing.
We typically measure water volume in cubic meters instead of gallons.
How many liters are in a cubic meter?
100 Bonus: How many gallons are in a cubic meter?
1 cubic meter is 1,000 litres
100 Bonus: 1 cubic meter is 264.17 gallons
This element is the most numerous of the mineral nutrients within the plant. It makes up to 20% of the total biomass of a plant by constituting the majority of the building blocks for proteins, nucleic acids, etc. It is important to balance this nutrient with potassium to steer plant growth.
100 Bonus: Name one of compounds of that element that is added to our grow zone.
Nitrogen
100 Bonus: Ammonium, Nitrate, CaNO3, KNO3, NH4NO3, MgNO3
Describe the role of iron in the formation of chlorophyll.
100 Bonus: What essential macronutrient is also key in the formation of chlorophyll?
Iron is used to create the precursor heme proteins later used in the creation of chlorophyll, but iron does not end up in chlorophyll itself.
When we add more energy (in watts) into a grow room than we remove, would you expect the grow room to accumulate heat or not?
200 Bonus: Does it take more energy (measured in watts) to create 100 mmol of blue light, or 100 mmol of red light?
The grow room would accumulate heat until the energy cycle would become balanced.
200 Bonus: It takes more energy to create 100 mmol of blue light than to create the same amount of red light.
True or False: Any species of bacteria or fungus can for symbiosis with plants.
100 Bonus: Name two species of beneficial microbes we use for our crops.
False: The symbiotes must be able to consume the exudates that are given to it by the plants, and provide benefits to the plant itself. Technically all saprotrophs help the plant by liberating nutrients, but not in close association with the plant itself.
100 Bonus: Bacillus subtillis, Trichoderma hazarium, Trichoderma viridens, Pseudommonas, Geobacillus, Sphingommonas, Glomus, etc.
Pressure is a force on a fluid given per unit area.
True or False: The same amount of force applied to a smaller diameter pipe of water creates a greater pressure than the same force applied to a larger diameter pipe.
200 Bonus: Do we use Kpa or PSI in most of our measurements? How many Kpa = 1 PSI?
True: Same amount of force in a smaller pipe would create a greater pressure than the same force in a larger pipe since the pressure is determined by unit area.
200 Bonus: Kpa should be standard, 1PSI = 6.9Kpa
This element is important for the formation of phospholipids, ATP, and is typically limited in the natural environment.
100 Bonus: Name the compound of that element that is added to our grow zone.
Phosphorus
100 Bonus: Monopotassium Phosphate, Phosphate
Name 2 of the 5 nutrients that can have an anatgonistic relationship with iron.
300 Bonus: 100 points each for the remaining 3 nutrients (up to 300 points)
Calcium, Copper, Manganese, Phosphorus, and Zinc
What is it called when we transfer heat through a heat exchanger, water cooling system, etc. where the two materials are physically touching and there is no air gap.
Conduction
True or False: Brassicas are famously known to not form symbiotic relationships with endosymbiotic plant growth promoting microbes.
False: Brassicas do not form those symbiotic relationships.
What is it called when there is a more viscous part of gas or liquid near the surface of a solid object that creates a velocity gradient.
100 Bonus: Why does it matter to us?
Boundary layer
100 Bonus: It is particularly important for us since the dryer air we are passing over the plants may not come in close contact with the plants due to the more humid boundary layer of air surrounding the leaves.
This element is important because it forms essential enzymes and the plant uses it to control osmoregulation through the roots and the stomata's guard cells.
100 Bonus: Name the compound of that element that is added to our grow zone.
Potassium
100 Bonus: Monopotassium phosphate, Potassium chloride, Potassium nitrate.
Describe what is meant when iron is described as chelated.
200 Bonus points: Name two types of chelated iron that we use in our nutrient mix.
Iron is bonded with an organic molecule to stabilize it and protect it from pH and oxidation changes.
200 Bonus: DPTA, EDHA, EDTA - Prayon doesn't count
Our grow lights do not emit infrared radiation (different than far red), but if we were growing crops with HPS or mercury vapor bulbs that do emit infrared radiation, what method of heat transfer would occur when the lights warm the lettuce leaves?
Not totally dissimilar to how the sun's rays or a bonfire would transfer heat.
Thermal radiation
Describe the differences between ecto- and endo- mycorrhizal fungi
Ectomycorrhizal fungi grow on the surface of the roots, covering them with mycelium. (most common in trees)
Endomycorrhizal fungi grow in between root cells to form their symbiosis. (what we see most in our plants)
Do we aim for laminar flow or turbulent flow with the airflow in our growzones?
100 Bonus: Why?
200 Bonus: Describe the difference between the two types of airflow.
Laminar is the goal, but difficult to achieve
100 Bonus: The energy required and the effect on the plants.
200 Bonus: Laminar airflow is when low flow or small obstacles allow air to flow in an organized way smoothly across different boundary layers. Turbulent flow is created by irregular eddies and inconsistent flow with higher speeds and larger obstacles.
This element is key for the formation of chlorophyll, as well as other enzyme functions. It has an antagonistic relationship with calcium since they are very close on the periodic table.
100 Bonus: Name the compound of that element that is added to our grow zone.
Magnesium
100 Bonus: Magnesium sulfate, Magnesium nitrate
Iron is not commonly incorporated into the structure of the plant because it is a catalytic cofactor. It can easily transfer between two states and is therefore used by the plant to move electrons around. What are these two states?
Fe+? --> Fe+?
Fe+2 and Fe+3