The purpose of this experiment is to compare the oxygen production of plants grown using different hydroponics systems. This project is significant because astronauts need a renewable supply of oxygen in space as well as a food source. Hydroponically grown vegetation will also be useful for the terraformation of other planets and moons. This project was meant to determine the amount of oxygen produced in percent using different hydroponic techniques. It was hypothesized that the ebb and flow technique would allow Camarosa strawberry plants, Fragaria xananassa, to produce the most amount of oxygen on average. The independent variable was the technique used and the dependent variable was the amount of oxygen produced. The plants were grown in ten gallon tanks sealed off with duct tape. The oxygen was measured in percent of oxygen using a Biochemical Oxygen Demand (BOD) meter. The data from this experiment did not support the researcher's hypothesis. There was not enough of a difference between groups to say one group produced more oxygen than another. Unforeseen variables have been detected in this experiment. The plants deteriorating after a few days, which may have been caused by high humidity since the tanks were sealed.
Last year, the researcher tested three different types of growing methods: hydroponics, aquaponics, and geoponics (soil). The geoponics group was the group with the highest percentage of oxygen, but it is less cost effective because soil wouldn't be used for anything else but the plants while in space in addition to being heavy. Because of this, the researcher decided to continue on with hydroponics, the group that produced the second highest percentage of oxygen.
This experiment is designed to compare the oxygen production of plants grown using three different hydroponics medias. The purpose for needing to know which method produces the most oxygen is because astronauts need a system that will renew the oxygen source and eliminate the carbon dioxide build up in their living quarters as well as provide a steady food source for long term missions.
The purpose of this experiment is to compare the oxygen production of plants grown using different hydroponics systems.
Independent variable: hydroponics technique used
Dependent variable: amount of oxygen produced
H1: The plant grown using the flood and drain technique will produce the most amount of oxygen.
H2: The plant grown using the top irrigation technique will produce the second most amount of oxygen.
H3: The plant grown using the passive subirrigation technique will produce the least amount of oxygen.
Changes in techniques will have no effect on the oxygen production of Camarosa strawberries.
Photosynthesis
The process in which plants produce oxygen is called photosynthesis. Photosynthesis means "putting together with light". The photosynthesis process takes place in the chlorplasts mainly using chlorophyll, which absorbs sunlight. During this process, the plant produces oxygen and releases it. As long as the plant gets its required amount of light, it should produce plenty of oxygen. The formula for photosynthesis is 6CO2 + 12H2O ---> C6H12O6 + 6H2O + 6O2, which means six water molecules plus six carbon dioxide molecules produce one molecule of sugar plus six molecules of oxygen.
Hydroponics in General
Hydroponics is the study of growing plants in materials other than soil. Hydroponics means "water works". According to Martin P.N. Gent (1998), the leaves on hydroponically grown plants are more succulent and thicker than those grown in soil. There are several different medias including, but not limited to: diahydro, expanded clay, rockwool, coco coir, perlite, vermiculite, sand, gravel, brick shards, and polystyrene packing peanuts. There are also many techniques, some of which are passive subirrigation, continuous flow, aeroponics, passive subirrigation, flood and drain (ebb and flow) subirrigation, top irrigation, and deep water culture.
Hydroponics Techniques
There are many hydroponics techniques. Some techniques are more suited for one type of plant than another. It is important to choose carefully when it comes to techniques as one may yield better results than another, depending on the plant. Here are a few:
Static Solution Culture
Plants are grown in containers of nutrient solution. The plants are usually aerated. If unaerated, leave room above the solution for the plants to get oxygen.
Continuous Flow Culture
The nutrient solution constantly flows past the roots. One popular version is the Nutrient Film Technique.
Aeroponics
In aeroponics, the plant's root are periodically sprayed with a nutrient solution. Aeroponics is extremely effective for growing trees and other thick rooted plants.
Passive Subirrigation
This technique includes using large air space to allow necessary oxygen to get to the roots. It consists of allowing a plant to continually sit in a nutrient solution. Can use many different medias for this technique, including vermiculite, perlite, rockwool, and gravel. Doesn't require too much care, just wash out the system periodically to prevent too high of a salt accumulation.
Flood and Drain (Ebb and Flow) Subirrigation
Usually consists of a reservoir of nutrient solution below a tray filled with growing media. Using a timer, a pump regularly fills the upper tray with solution, which eventually leads back down into the reservoir.
Top Irrigation
In this technique, nutrient solution is periodically applied to the surface of the media, either by hand or machine.
Deep Water Culture
This technique introduces the idea of using oxygenated water. The plant is place in the water with some means of supporting it.
Medias
Medias are an important part of hydroponics as plants need something to support them. Just like techniques, medias are dependent on the type of plant and also the technique. Here are a few medias:
Diahydro
Diahydro is made up of fossilized algae (or diatoms) shells that are millions of years old. Diahydro is high in silica, a necessary item to help along the plant's growth and to strengthen its cell walls.
Expanded Clay
Expanded clay is clay baked into different shapes, usually balls or pebbles. They can be reused for multiple plants.
Rockwool
Rockwool is basalt rock, heated at a high temperature and spun into different shapes, usually cubes. It is essential to try not to inhale any part of rockwool as it may carry a health risk.
Perlite
Volcanic rock that has been heated into expanded, light, glass pebbles.
Vermiculite
Similar to perlite, it has been heat until it expanded into pebbles. It also holds more water than perlite.
Sand
Sand is probably one of the least practical choices as a media since it doesn't drain well, can clog up the roots, and had to be sterilized between uses. However, it is cheaper than other medias.
Gravel
If using gravel, wash it before use. It has many advantages, as it's cheap, easy to clean, and won't waterlog.
Hydroponics in Space
Hydroponics is important in space travel, as astronauts need a steady supply of food and oxygen. NASA is trying to find suitable crop plants to send up to space. They are growing the plants hydroponically as well as testing the characteristics of the plants. NASA tests how the plants react with other plants in the same general area as it (the plant might give off poisonous chemical compounds, killing the neighboring plants), testing the amount of nitrogen the plants consume, and seeing how the plants are affected with changes in atmospheric pressure. The plants will do more than give astronauts a food source - they will eliminate toxic carbon dioxide from the air and filter out waste. However, hydroponics has its limits as well. "You can't have open containers of water to grow plants in," says Dr. Bill Knott, "In microgravity, water wouldn't stay where you put it. Instead, astronauts would likely use water soaked materials, including cloth strips, to provide moisture to the plants."
History of Space Travel
The Beginning
People have been studying our solar system for hundreds of years. However, it wasn't until October 4, 1957 that the "Space Race" between Russia and the United States began, when Russia launched Sputnik 1. Sputnik was about the size of a basketball, weighed 183 lbs, and it orbited the Earth in 98 minutes.
Mercury Project
About a year after the launch of Sputnik, NASA (National Aeronautics and Space Administration) was created and began the first U.S. man-in-space program, known as the Mercury Project. The Mercury Project ran from 1958-1963. Mercury's goals were "to orbit a manned spacecraft around Earth", "to investigate man's ability to function in space", and "to recover both man and spacecraft safely". Mercury's spacecraft resembled a cone with a cylinder mounted upon it. Mercury's astronauts were Alan Shepard, Virgil "Gus" Grissom, John Glenn, M. Scott Carpenter, Walter Schirra, and L. Gordon Cooper.
Gemini Project
The Gemnini Project started in January of 1962. It's goal were "to subject man and equipment to space flight up to two weeks in duration", "to rendezvous and dock with orbiting vehicles and to manuever the docked combination by using the target vehicle's propulsion system", and "to perfect methods of entering the atmospher and landing at a pre-selected point on land".
Apollo Program
The Apollo Program's goals were to "establish the technology to meet other national interests in space", "achieve preeminence in space for the United States". "carry pit a program of scientific exploration of the moon", and "develop man's capability to work in the lunar environment".
Apollo-Soyuz Program
The Apollo-Soyuz Test Project was meant to "test the compatibility of rendezvous and docking systems for American and Soviet craft." The program used the American's Apollo spacecrafy and Russia Soyuz spacecraft, hence the name of the project.
Skylab
The point of the Skylab Space Station project was to prove humans could live in space for long periods of time and to advance our knowledge of solar astronomy. The first Skylab was unmanned. The second Skylab mission ran from May 25, 1973 - June 22, 1973, a total of 28 days, with Commander Charles Conrad, Pilot Paul Weitz, and Scientist Joseph Kerwin. The third Skylab mission ran from July 28, 1973 - September 25, 1973, a total of 59 days, with Commander Alan Beran, Pilot Jack Lousma, and Scientist Owen Garriot. The final Skylab mission ran from November 16, 1973 - February 8, 1974, a total of 84 days, with Commander Gerald Carr, Pilot William Rogue, and Scientist Edward Gibson.
Mir
Mir Space Station was launched February 20, 1986. It reentered on March 23, 2001.
Benefits of Hydroponics
Hydroponics has many benefits. It provides year round gardening, it is more sanitary, and there is no digging or weeding involved. Hydroponically grown plants grow 30%-50% more than soil grown plants under the same conditions. Scientists believe hydroponically grown plants grow faster because the mediums they are grown in contain more oxygen than soil. Plants with plenty of oxygen in their roots absorb nutrients faster. Hydroponically grown plants don't have as many problems with parasitic insects and disease. Generally, hydroponically grown plant are healthier. Hydroponics uses less water than soil plants because of the constant reuse of the nutrients and less pesticides. Also, topsoil erosion isn't an issue because there is no topsoil. Hydroponics provides plant life in almost every environment because it doesn't require soil.
Disadvantages of Soil
As with most things, hydroponics does have a downside. Hydroponics is generally more expensive and requires more of a technical knowledge than geoponics. The plants also need more attention than soil grown plants. There are also some misconceptions concerning hydroponics. The plants aren't always healthier or contain a more prominent or delicious taste than geoponically grown plants.
Camarosa Strawberries
Camarosa strawberries are spring bearing plants. They were created by the University of California and introduced in 1993. Camarosas are rain-tolerant, hardy plants with bright coloring. They grow best in Southern areas.
Title: Producing Oxygen for Space Travel: A Comparison of Various Hydroponic Techniques
Hypotheses
H1: The plant grown using the flood and drain technique will produce
the most amount of oxygen.
H2: The plant grown using the top irrigation technique will produce the
second most amount of oxygen.
H3: The plant grown using the passive subirrigation technique will
produce the least amount of oxygen.
Null Hypothesis: Changes in techniques will have no effect on the oxygen production of Camarosa strawberries.
Independent variable: hydroponics technique used
Dependent variable: amount of oxygen produced
Constants: amount of light, type of light
Safety Methods
Hazard: chemicals
Precautions: Always have adult supervision nearby. Wear goggles, gloves, and an apron at all times when working with chemicals.
Organism Information
Common Name: Camarosa Strawberry
Genus Name: Fragaria xananassa
Description: bright red strawberry, extremely firm and hardy
Source: South Brevard Nursery
Experimental Methods
Making Hydroponic Solution
Materials
13 1/2 oz sodium nitrate
4 1/2 oz potassium sulfate
10 oz superphosphate
4 oz magnesium sulfate
Trace elements (see below)
100 gal water
To mix less than 100 gallons of water, merely mix and store the larger quantity of powders, then use at the rate of four tsp per gallon or 1/2 lb to 25 gallons. For larger quantities, simply multiply the formula.
Trace element mix
1 oz iron sulfate
1 level tsp manganese sulfate
1 level tsp boric acid powder
1/2 level tsp zinc sulfate
1/2 level tsp copper sulfate
Mix well and store dry. Use 1 gram (about 1/2 tsp) per 100 gallons of nutrient solution. For smaller batches, dissolve 112 tsp of the trace mix into one quart of water, use 1 liquid oz per 3 gallons of nutrient solution. Do not try to save any unused trace mix solution.
Building Systems
1) Fit plexiglas to each ten gallon tank.
2) Cut a hole and make a flap in one corner of all the plexiglas tops
3) Create two PVC sprinkler systems for the top irrigation group.
4) Create a shelving system for the plants in the top irrigation and flood and drain groups.
5) Cut a pool noodle into 20 pieces; each piece being an inch and a half thick.
6) Cut balsa wood into ten inch and a half pieces and sixteen three ince pieces.
7) Bend the sides of the trays so they are straight.
8) Pour hydroponics solution into a bucket.
9) Pour perlite into the bucket with hydroponics solution to get rid of excess dust.
Setting up the Systems
Passive Subirrigation
1) Clean off dirt from ten plants.
2) Place one plant in each pool noodle piece; if necessary, cut the holes larger. Repeat with the other plants.
3) Fill tank about a fourth of the way up with hydroponics solution.
4) Using the balsa wood pieces, connect the noodle pieces together to prevent the plants from flipping over.
5) Seal off the tank with duct tape.
6) Repeat with the other passive subirrigation group.
Top Irrigation
1) Clean off dirt from ten plants.
2) Cut a hole in the side of the tray for the pump.
3) Fill tray with perlite.
4) Plant the strawberries in the perlite.
5) Hook up the pump and insert tubing in tray through hole.
6) Seal off tank with duct tape.
7) Repeat for other top irrigation group.
Flood and Drain
1) Clean off dirt from ten plants.
2) Cut a hole in side of tray for the pump.
3) Fill tray with perlite.
4) Plant strawberries in perlite.
5) Hook up the pump and insert tubing in tray through hole.
6) Seal off tank with duct tape.
7) Repeat with other flood and drain group.
Geoponics
1) Fill tank about a quarter of the way up with soil.
2) Loosen up soil from ten plants.
3) Plant strawberries in soil.
4) Seal off tank with duct tape.
5) Repeat with other control group.
Measuring Oxygen Production
1) Turn on BOD meter.
2) Zero the meter.
3) Connect probe to meter.
4) Wait about five minutes for meter to warm up.
5) Calibrate the meter.
6) Insert meter into precut hole in plexiglas.
7) Wait a few minutes.
8) Write down measurement on screen.
9) Repeat steps 6-8 for all other groups.
Culturing materials
8 ten gallon aquarium tanks
80 Camarosa strawberries
1 BOD meter
2-3 sheets of plexiglas
4 metal trays
8 lights
3 bags of perlite
Hydroponics solution
76.4 grams sodium nitrate
56.6 grams calcium phosphate
25.5 grams potassium sulfate
22.6 grams magnesium sulfate
2.5 grams boric acid powder
2.5 grams iron sulfate
2.5 grams manganese sulfate
1.2 grams copper sulfate
1.2 grams zinc sulfate
Building materials
4 PVC elbows
12 PVC end caps
4 PVC Ts
2 PVC sticks
I. Calculating the mean
- Open up a spreadsheet.
- Make a column for each group and trial.
- Calculate mean for each group and trial.
- Use the spreadsheet graphing program to create a graph
- Repeat for all groups.
- The two bars in the four individual graphs represent the average oxygen production of each trial.
- The four bars in the overall graph represent each technique's average oxygen production.
The data from this experiment did not support the researcher's hypothesis. The flood and drain technique did not produce the most oxygen. Unforeseen variables have been detected in this experiment. The plants began deteriorating after a few days, which may have been caused by high humidity, since the tanks were sealed. Also, the plants were created by the University of California, which may have also had an effect on their mortality, seeing as they aren't a natural species.
Garber, Steve. Sputnik. Retrieved on October 23, 2006 from: http://www.hq.nasa.gov/office/pao/History/sputnik/index.html
Grinter, Kay. Apollo. Retrieved on November 1, 2006 from: http://www-pao.ksc.nasa.gov/kscpao/history/apollo/apollo.htm
Grinter, Kay. Apollo Soyuz Test Project. Retrieved on November 1, 2006 from: http://www-pao.ksc.nasa.gov/kscpao/history/astp/astp.html
Grinter, Kay. Gemini. Retrieved on October 26, 2006 from: http://www-pao.ksc.nasa.gov/kscpao/history/gemini/gemini.htm
Grinter, Kay. Mercury. Retrieved on October 26, 2006 from: http://www-pao.ksc.nasa.gov/kscpao/history/mercury/mercury.htm
Grinter, Kay. Skylab. Retrieved on November 1, 2006 from: http://www-pao.ksc.nasa.gov/kscpao/history/skylab/skylab.htm
Holland Hydroponics. The Benefits of Gardening Hydroponically. Retrieved on August 11, 2006 from: http://www.hydroponics.co.uk/data_sheets.htm
