Why is Hydroponics the Best Method for Growing Plants?

JASNEET BAINS

she/her | age 16 | London, ON

TVSEF Silver Award and monetary prize award

Most of the nutrients we consume are from the food we eat. This is the same as how plants get their food too, but they get their nutrients from the soil. For plants to be healthy, they need macronutrients. This includes carbon, nitrogen, and phosphorus. Plants also need micronutrients and this includes iron, sodium, and zinc. Soil has micronutrients and macronutrients, but purified water does not. For the process of purifying water, it removes contaminants that are harmful to plants, but it also removes minerals that are healthy for plants. This can then cause stunted growth (plant disease) and discoloration (change in color of leaves, flowers, or stems), because they are not getting the nutrients that they require to have proper growth. This is why, in this science experiment, I will be conducting research on why the Hydroponic Plant System (HPS) is the best method for proper plant growth. Hydroponics is a method that is not used often and is a term that defines a method where plants are grown in a nutrient solution rather than used in soil. In this project, I will explore why using HPS is the most effective method for growing plants, and why it should be implemented among the public.

INTRODUCTION

Plants need water and they use it in many different ways. Water acts as a solvent (dissolves easily) and helps to transport nutrients from the soil throughout the entire plant. Also, the water fills the cells to help support many biochemical reactions that occur in plants. A biochemical reaction is a reaction that occurs between chemicals inside the plants, in order for them to stay alive. For example, plants go through the process of photosynthesis, which is a biochemical reaction. Photosynthesis is a reaction that involves the sunlight, the chlorophyll in plant cells, water, and carbon dioxide. Then, it produces sugar for the plants to consume as food. So, if plants did not receive water, photosynthesis or any other biochemical reactions wouldn’t occur in the plant. This will then result in the plant turning yellow, drying up, and then eventually dying.

Environmental conservation, the practice of protecting our environment and natural resources, is one of the biggest challenges that society faces. The United Nations Food and Agriculture Organization presents that there is a common cause of anthropogenic soil pollution. This is caused by the greenhouse effect that comes from farmers. Hydroponics is the best method to prevent climate change, reduce environmental damage, and species extinction because of intensive farming. It is also the best method to prevent the fight for hunger. The term is best known for smart farming because it uses technical tools to have greater yield from crops. However, hydroponics can also create higher yields; it can produce more food and there is no use of pesticides. It also has lower water consumption as it consumes 20 times less than conventional agriculture. There is also less contamination involved because it is a closed system. Overall, hydroponics is a method that can be used in all types of weather conditions, and these plants can also grow in harsh environments with poor soil or extreme weather conditions.

The question then, is whether it is necessary for there to be soil in order for plants to be alive or can plants just survive in water? What would happen if the water was just filled with the nutrients that plants need without using soil? According to New Mexico State University, plants can survive without being planted in soil. In this experiment, I will be using the Hydroponics plant method (HPS); this is the method where the nutrients will be available at the plant’s roots. This is how the plants will be getting their food and nutrition. When we plant any plants in soil, the roots must exert a great amount of energy to extract the nutrition from the soil and can also waste a lot of energy using this method. But, if we just use nutrient-rich water and not use soil, then the roots can use the energy for growing bigger leaves or flowers in a short period of time. The plant will also receive the exact amount of nutrients needed for the plant to grow. There are many advantages of using the HPS, including how hydroponics will also work in areas where the soil might not be suitable for farming, or in areas that do not have soil. According to NASA, they are also doing a project on hydroponically grown plants (NASA, 2021; Figure 1).

**Figure 1:** NASA plant physiologist at the Kennedy Space Center, examining his hydroponically grown plants.

My hypothesis is that using the HPS will make my plants grow faster in a couple of days and will be healthier. I think using the HPS will be more effective than just planting plants in soil, which I will be proving with all my research and my experiment. I also hypothesize that plants do not just need soil to grow, and using the HPS, plants can grow in any sort of weather conditions, or even in areas where the environment is not suited for agriculture.

MATERIALS & METHODS

The materials that I used to plant one of the spinach plants with the HPS method are the following: Two-liter plastic soda bottle (emptied and cleaned), permanent marker, scissors/utility knife, thick cotton/felt strips, coconut coir, seeds (1 package), purified/filtered water, disposable gloves, nutrient solution, measuring spoon, large container, lab notebook (to record results), and a ruler.

In this experiment, I grew spinach using the HPS. I conducted this experiment by planting spinach seeds in regular soil and water, and planting spinach seeds using my very own HPS, but everything will remain the same. To recall, HPS is the process where the plants will grow in a medium that retains moisture but does not contain nutrients. The medium that we will be using will add the structure for the plants.

My first step was to add water to the coconut coir to help loosen it. The coconut coir will act as the growing medium for the plants. When I added the water to the coconut coir, it expanded more. Then, I used the permanent marker to draw a line across the bottle, and then used the line as a reference, I have cut the bottle. Afterwards, I flipped the top upside down, and the plant grew from the upside-down part. The bottom part of the bottle acted as the reservoir to hold the water. I then created a wick; I created the wick by knotting two cotton or felt strips together at the end. The wick helped in transferring the nutrient-rich water from the reservoir to the plants. I then pushed the loose ends through the bottle, and placed the top with the wick into the bottom part of the bottle.

I filled the top part of the soda bottle with the coconut coir. To prepare the nutrient-rich water, I added 1 ¼ cup of water, and one cupful of the nutrient solution. Afterwards, I mixed this solution and poured it into the coconut coir. Then, I put the seeds into the coconut coir. I wrapped the soda bottle in aluminum foil to prevent algae growth, and then my HPS is ready!

The independent variable in this experiment will be the planting system and type of seeds that I have used. The dependent variable in this experiment is the height of the plant. Lasty, the controlled variable in this experiment would be the location and the nutrient solution.

RESULTS

In this experiment, I first planted the spinach plants using the HPS on March 7th, 2023. I have been watering my plants using 1 ¼ cup of water with one capful of the nutrient solution, which is clearly described on the nutrient solution bottle. On March 14, I also watered my plant using the nutrient solution with the same measurements. Afterwards, on March 21st, I again watered my plant using the same materials and measurements. I have conducted this experiment two times, one with aluminum foil, and one without aluminum foil. I have observed that the one with the aluminum foil is growing faster than the one without. This can be because aluminum foil can affect the plant growth rate. After I conducted my research, I found out that when the aluminum foil is kept near the plants, the aluminum foil refracts the light up into the plant from the ground. This will cool the coconut coir around the plants, which allows the plant to retain more moisture. Also, using the aluminum foil increases the process of photosynthesis as well.

Referring to the HPS, the one with no aluminum foil only grew up to 4 cm, and the one with aluminum foil grew up to 6 cm. For a plant that is not grown using the HPS, it will normally take up to 1-2 weeks to sprout. But, using the HPS, it only takes up to 3-5 days. The coconut coir allows more oxygen for the roots, which increases proper plant growth, as it can absorb nutrients better.

DISCUSSION

Therefore, after all the research I have conducted, and presenting my very own HPS, this strategy has shown to perform better than using soil as the medium for growing plants. Using the HPS, the plant is receiving the right conditions in order to grow. It is 50% faster than growing plants using soil and water. Plants that are grown using the HPS can also grow even on the days without sunlight, or in the winter conditions. More yield is also achieved from each plant using this system. Even though Hydroponic Plants are grown in a nutrient-based solution, they are better than organic plants. The nutrient-based solution that is used in Hydroponic plants is purer than the fertilizers used in organic plants. If we use the HPS more, then more people can be fed, less natural resources are used, and the outcome is healthier and more flavorful. Hydroponic plants are grown indoors, so the plants used in this system are free from pesticides and chemicals, which makes these plants unique. Therefore, plants that are grown using the HPS are more efficient and healthier than using the method of growing plants in soil and water.

REFERENCES

D'Anna, C. (n.d.). Learn the basics of hydroponics: The most efficient gardening method. The Spruce. Retrieved March 23, 2023, from https://www.thespruce.com/beginners-guide-to-hydroponics-1939215

Food Revolution Network. (2023, January 19). Hydroponics: How it works, benefits and downsides, & how to get started. Food Revolution Network. Retrieved March 23, 2023, from https://foodrevolution.org/blog/hydroponics/

Hydroponics. Hydroponics | National Agricultural Library. (n.d.). Retrieved March 23, 2023, from https://www.nal.usda.gov/farms-and-agricultural-production-systems/hydroponics#:~:text=Hydroponics%20is%20the%20technique%20of,%2C%20 hobbyists%2C%20and%20 commercial%20 enterprises.

Issue: December 14, 2002. Plants without soil. (n.d.). https://aces.nmsu.edu/ces/yard/2002/121402.html