Hydroponics (page 2)
Results will vary, but healthy potted plants can mature and bear fruit in a hydroponic environment.
Growing plants in a 100% liquid nutrient solution without a supporting medium is called aquaponics. In this experiment, the paper products provide support for each plant's root and stem system, but they do not add nutrients to the plant. As long as the medium in which the plant is grown does not add nutrients and all the nutrients derived from a nutrient solution, the method of growing is considered to be hydroponic. The hydroponic growing unit, a hydroponicum, fits this description.
Try New Approaches
- Does the amount of sunlight received by a tomato plant affect its growth? Repeat the procedure to prepare six hydroponicums of tomato bedding plants. Place two plants in each of the following situations: all day sun, morning sun, and evening sun. You may have to use shields made of boards to block the sun from directly hitting the plants that are to receive only partial sunlight (see Figure 16.2). Keep daily records. Measure the height of each plant, count the leaves, and note the general appearance of the plant's leaves and stem. Science Fair Hint: Prepare and display a graph to represent the growth of each plant (see the sample graph in Figure 16.3).
- Does the amount of oxygen received by the roots affect the growth of the plant? Prepare three hydroponicums using tomato bedding plants. Place a small aquarium aerator in each jar. Allow the liquid in the three units to be aerated for different time periods, such as 2, 8, and 24 hours.
- Can other plants be grown hydroponically? Repeat the original experiment using bedding plants such as strawberries or flowering plants.
- Does a growing medium affect the results? A plant can be considered hydroponically grown as long as the medium does not provide nutrients to the growing plant. Plant a tomato bedding plant in a nonnutrient medium such as LECA (light expanded clay aggregate), sand, gravel, charcoal, sawdust, and vermiculite or perlite. You could choose to use several mediums and compare their results. Use the prepared liquid nutrient from the original experiment.
Design Your Own Experiment
If the same nutrient additive is used, do terrestrial plants grow better than hydroponic plants? Plant three tomato bedding plants in soil. Follow the instructions from a professional at a nursery for the planting and care of the plants. Use the same nutrient solution to water both the plants in the hydroponicums and those in the soil. Take photographs of the different stages of growth of each plant, noting the date and time you take each photograph. Be sure to include pictures of the fruit grown from the plants. Use the sample plant growth graph (Figure 16.3) to prepare graphs for each plant. Display the photographs to represent procedure, steps and results. Display several of the graphs to show the comparison between geoponic (grown in the earth) and hydroponic growth.
Get the Facts
- What nutrients are needed for proper plant growth? Use a gardening book to find the elements required for plant growth and their source and functions. What are the symptoms of specific nutrient deficiencies?
- Seaweed is an example of growth by natural aquaponics. What other plants grow aquaponically in nature? You could display pictures of these plants to show productive aquaponic growth.
- What are the advantages of hydroponics over geoponics? Find out more about growing plants in liquid instead of soil. Is it more or less expensive? Is it more productive? Is it more environmentally sound?
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.