We noticed that a lot of irrigation systems have timers so that it waters itself. It might not always need water when the timer goes off or it might need a different amount of water. We know that water shortage is a problem around the world and when the timer goes off to water the plants, if it doesn't  need water then all that water goes to waste. We think that if we coded our own plant watering system that measures the soil moisture and only gives it water when the plant needs more moisture, we will not waste as much water. We wondered if this would help people (farmers) save water. For our science fair project we wanted to see if there was a way to grow crops and waste less water. Our scientific question is:

Can coding an automatic plant watering system increase efficiency in water use and agriculture?

HYPOTHESIS:

Experimental Hypothesis:

If different plant watering methods (coded, timer, wool, and hand watering) are used on the same type of plant, then the plant watered by the coded one will have the healthiest growth and least amount of water wastage because the  system's can adjust watering based on real-time moisture levels, compared to the other methods which either deliver water at set times or depend on people. 

•  ChatGpt - Paraphrased (ChatGPT, n.d.) 

Our hypothesis predicts that the coded system will do better than the timer, wool, and hand watering methods by using less water and keeping the plant alive.

• Paraphrased

Design hypothesis:

We expect that when we change the method of watering (Coded, Timer, Wool, & Hand Watering) we will find that the coded one uses the least amount of water because it measures the soil moisture and gives it the exact right amount of water that it needs when it needs it.

How do plants use water to grow? (Bugbee, 2018) (Grammar, 2022)

• “Agriculture is the world's greatest consumer of our water resources. Globally about 70% of human water use is for irrigation of crops. In arid regions irrigation can comprise more than 80% of a region's water consumption.”
• This part of our research shows that agriculture takes up most human water consumption.
•  This research shows just how much water waste develops in agriculture. This relates to our question because it proves that water waste is happening with irrigation timers and how we can code one that does the opposite.
• The plant pulls its nutrients from the soil. Water makes the minerals dissolve then it moves through the plant. This is called “Mineral Nutrients.”
• “Photosynthesis is the process that produces organic molecules from simple inorganic molecules from the sun's energy. Not only does photosynthesis require water, but it also creates water as a byproduct of the reaction. This means that water is essential for a plant to produce its own food.”
•  This shows just how important water is not only to regulate its temperature but to create photosynthesis and helps produce food for itself.
•  
• How does the type of plant & pot affect how much water it needs? (Celtic Farm, 2023)
•  
• “For indoor plants and those grown in containers, the size and material of the pot play crucial roles. Smaller pots dry out quicker than larger ones. Similarly, pots made from porous materials like terracotta lose water faster than plastic or glazed ceramic pots.” 
• This research is important because now we can start figuring out how we are going to choose our pot based on what we just learned about the different ways that plants grow.

• This research told us what kind of place in our house we want to put them because the hydration can change. Plants need sunlight to grow and that will depend on where we put the plants.
• Different plant types have already adapted to their environment so cactus and other plants that live in deserts already keep water in their leaves, stems, and roots so they will need less water, but more plants that live in warmer areas might need more water than others.
• This specific research helps us because now we can start figuring out how we are going to choose our pot based on what we just learned about the plants' humidity and soil moisture.

How does temperature affect the amount of water that the plants need? (Canna Research, 2014)  (Water Science School, 2018)

• “Most biological processes will speed up at higher temperatures, and this can have both positive and negative effects. For example, faster growth or fruit production is one benefit, in most cases. However, the excessive respiration that occurs is adverse because it means that there is less energy for fruit development and the fruits will be smaller. Some effects are short term, while others are longer term. The plant’s assimilation balance, for example, is influenced by the temperature and is affected immediately. Flower induction, on the other hand, is determined by the climate over a much longer period.” 
• This quote shows that the air temperature that the plant has to either decrease the plants energy and make it smaller or make it bigger. We know that this will help us decide what room temperature is better for our plants' health.
• This is important because we know what will happen to the plant if the air temperature changes and how it evaporates the water to cool down. 
• This is important to our project because now when the different parts of the plant react differently to temperature now we will know what room to put our plants in and what temperature it needs to be in order for our plants to grow better.
• This is important to our project because it shows what happens when you make water cooler or warmer and what that does to the chemicals in it.
• This shows that when you change something in the water (LIke the dissolved oxygen) then the water changes (Concentrated Water).

What watering systems already exist in agriculture? (Tremblay, 2024)

• Sometimes when you put your plants in an irrigation system it over waters your plants when it doesn't need it. Sometimes it also doesn't give the plant nearly as much water as you need it too. It depends on what you put your irrigation timer at. This research shows us what different watering systems already exist in agriculture and how the different systems affect the plants health.
• Manual irrigation: Manual irrigation is when you water plants by hand. It is much less efficient but it can be more economical because you don’t have to buy any equipment or machinery.
• Sprinkler irrigation is like rainfall by spraying water into the air and letting it fall over the plants. How the different irrigation systems act like rain and spray mist because certain plants have different ways of growing.”Sprinklers can be adjusted for water pressure and range.” 
• Surface irrigation: surface irrigation is when you just use gravity to water your plants or crops. There are so many different ways to water your plants and how irrigation systems use the earth to work.

How does  temperature affect the amount of water that the plants need? (Canna Research, 2014) (Water Science School, 2018)

• This research shows that the air temperature that the plant has to either decrease the plants energy and make it smaller or make it bigger. We know that this will help us decide what room temperature is better for the plant and what would be the best choice for it.
• Some different events that might affect the plants hydration or soil moisture are: “Weather patterns and climate conditions can significantly affect a plant’s hydration needs. During hot, dry periods, plants may require more frequent watering. In contrast, during cooler or more humid times, plants may need less.” 
• This quote shows that even plants change when the climate changes and how that affects their soil moisture and the humidity of the plant. All of this can affect how the plant grows overtime.
• “Plant temperature and air temperature are not equal because plants are able to cool off through evaporation and warm up through irradiance. Plants seek to reach their optimal temperature, and a balance between air temperature, relative humidity and light is important in this. If light levels are high, the plant will heat up, resulting in a difference between plant temperature and air temperature. To cool down, the plant’s transpiration rate must increase. As well as temperature, the transpiration rate depends on environmental conditions such as light, the level of atmospheric CO2 and relative humidity, but also on the species of plant.”
• This quote is evidence that plants can actually cool down and cool off when needed all they have to do is evaporate water.

How does the Soil Moisture affect the plant use of water? (Pandey, 2021) (Robock,, , 2003)

• 1-2 cm of the top layer of the soil is the active layer. That is the main source of water for agriculture and vegetation. Available energy is at the surface of the soil in 1-2 cm. Soil moisture is the source of water that evaporates through the plant's transpiration. Wetness of the surface will make the plant cooler. 
• Land cover is important to soil moisture and also land surface temperature major implications for agriculture ecology and wildlife and the hydrological cycle.
• Moisture happens in the organic layer of the soil where the energy is coming from and where land surface interfaces.

What amount/type of soil would be best for a sunflower plant? (Miraclegro, 2002)

• “Mixing 3 inches of garden soil into the top 6 to 8 inches of native soil. This will feed new plants and help build strong roots, both of which will mean big, beautiful blooms.”
• This relates to our research because it tells us how much soil our plant needs to have strong roots and to grow really well.
• “Sunflowers grow best in full, bright sun, and in evenly moist, well-drained soil. The amount of space they need depends on which varieties you are growing. Branching types with multiple blooms on one stem need more space horizontally than large single-flowered types. Take care to select a spot to grow taller varieties where they won’t throw too much shade on other shorter, sun-loving plants. The north side of the flower border is almost always a good spot.”
• This relates to our research because it tells us where we need to put our plants and how to grow our sunflowers.

References

Bugbee, B. (2018). Water is essential for food production. InTeGrate. https://serc.carleton.edu/integrate/teaching_materials/food_supply/student_materials/1090

Canna Research. (2014, APRIL 1). How air temperature affects plants. How air temperature affects plants. Retrieved January 15, 2025, from https://www.canna.ca/articles/how-air-temperature-affects-plants

Celtic Farm. (n.d.).

Celtic Farm. (2023, May 28). The Science of Hydration: How Much Water Do Plants Actually Need? The Celtic Farm. Retrieved January 6, 2025, from https://www.thecelticfarm.com/how-much-water-for-plants/

Grammar, B. (2022, July 21). The Science Behind Why Plants Need Water. Commercial Lawn Irrigation. https://www.commerciallawnirrigation.com/blog-posts/the-science-behind-why-plants-need-water

Pandey, D. K. (2021). Soil Moisture. Soil Moisture. Retrieved January 15, 2025, from https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/soil-moisture

Robock,, A. (, 2003). HYDROLOGY | Soil Moisture. ScienceDirect. Retrieved January 7, 2025, from https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/soil-moisture

Science Buddies. (2023). Science buddies arduino board lesson. Science Buddies. Retrieved January 16, 2025, from https://www.youtube.com/watch?v=cd04o5yqSAU&list=PLlBVuTSjOrclb0iCMSRpS_H1lSrlSVeEm

Tremblay, E. (2024, december 23). The 8 Types of Irrigation Systems You Should Know. The 8 Types of Irrigation Systems You Should Know. https://irrigationmontroyal.com/en/irrigation-systems-types/

Water Science School. (2018, June 6). Temperature and Water | U.S. Geological Survey. USGS.gov. Retrieved January 7, 2025, from https://www.usgs.gov/special-topics/water-science-school/science/temperature-and-water

Water Science School. (2018, June 6). Temperature and Water | U.S. Geological Survey. USGS.gov. Retrieved January 15, 2025, from https://www.usgs.gov/special-topics/water-science-school/science/temperature-and-water

WayinTop. (2020). Automatic plant watering tutorial. GitHub.com. Retrieved January 16, 2025, from https://github.com/WayinTop/Automatic-Plant-Watering-System-Tutorial/blob/master/Code/water.py

Manipulated: Method of watering.(Moisture meter, Timer, Wool system, hand watering.)

Responding: Amount of water used, Size/Height of plant.

Control: Type of plant, Amount/Type of soil, Size of pot, Temperature of the water, Air temperature, Amount of sunlight, Amount of growing time.

1. Put 2 cups of soil into each of the four pots.
2. Put 2 tablespoons of water into each pot.
3. Make 4 1-inch deep holes in each pot.
4. Plant the sunflower seeds in each of the holes. 
5. Label the pots.
6. Put them under the heat lamp with a 25w light bulb.
7. Put saran wrap on each of the pots.
8. For the next week give each of the plants 2 tablespoons of water a day.
9. After 1 week set up the 3 other methods of watering.
10. Each night turn the heat lamp off then turn it on each morning because plants like the cycle of day and night.
11. Every day, hand water the plant labeled hand watering and give it 3 tablespoons of water (45ml)
12. Fill out the charts for each plant.
13. Make sure the other three methods are working.
14. Repeat steps 10-14 for three weeks.

During our experiment we noticed some things about the different watering methods and how it impacted our plants. The coded method was watering the plants accordingly and the plants were thriving and were healthy. Then when the coded method stopped working the plants started to shrivel up and slowly get smaller. When I watered the coded one by hand the tallest plant started bringing itself backup and growing again.

We noticed that the timer method worked really well and we didn’t have to worry about checking on it too often. The timer method always started watering at 10:00 and 4:00 because we set it for 1 minute every 6 hours.

For the wool method we noticed that it was working surprisingly well for the first 11 days. After a while the water struggled to climb the wool to get into the plant. We also noticed that if the wool was touching the milk jug the water would come out of the wool Instead of going into the plant. 

For the hand watering method we noticed that after a while the plants started to Bend over and made it very hard to measure. It was hard to distribute the water evenly over the soil to let the other seeds have enough to thrive.  

RESULTS:

Table 1 and figures 1 and 2 show a summary of our data. 

The coded watering method used 800 ml of water and the average plant height was 23 cm.

The timer method used 750 ml of water and the average plant height was 30.5 cm.

The wool method used 375 ml of water and the average plant height was 18.5 cm.

The hand watering method used 675 ml of water and the average plant height was 35.5 cm.

DISCUSSION:

During our experiment, we found that the hand watering method worked better than the timer, coded, and wool (Manipulated variable) and it kept the plants alive the best (responding variable.) In our first graph (Amount of Water Used) it shows that the hand watering used the least amount of water besides the wool, which failed. In our second graph (Average Height of Plants) it shows that the hand watered plants had the highest average height. 

When we were doing the experiment, not all of the plants survived. Some of the seeds that we planted never sprouted and we broke some of them when we were trying to attach them to the supports.

Not all of our measurements were completely accurate because we did not have access to beakers to measure the amount of water used. We put 250ml of water in a milk jug and then drew a line at the water level and labeled it, and then repeated this until the milk jugs were at 2000ml. We then used those marks to help us estimate the amount of water used. All of the plant height measurements were as close as we could get to the actual height but they are not 100% accurate because the plants were slightly curved. We tried to gently straighten the plants to measure the height but we did not want to risk breaking them because they were very fragile.

Our wool method worked for the first  11 days and then it just stopped working. We don’t know what happened but it might be that the water level got too low and then the water could not climb up the wool enough to get over the edge of the milk jug.

CONCLUSION:

In conclusion we found that the hand watering method worked best by a combination of  low water usage and highest average plant height. Our hypothesis was incorrect. We thought that the coded method would work the best.

Our project would impact the real world by helping people waste less water around the world and in agriculture. We know that water shortage is a problem that most of the world faces every day. It does not save that much but every little bit counts.

Some of our sources of error were: The wool did not work and stopped watering after a few days (Put exact number of days) days. Because it stopped watering our plants, the plants died. After about two weeks, the coded device stopped connecting to the laptop, and all of the plants died as well. We also struggled to get the coded method wired properly and working.

References

Bugbee, B. (2018). Water is essential for food production. InTeGrate. https://serc.carleton.edu/integrate/teaching_materials/food_supply/student_materials/1090

Canna Research. (2014, APRIL 1). How air temperature affects plants. How air temperature affects plants. Retrieved January 15, 2025, from https://www.canna.ca/articles/how-air-temperature-affects-plants

Celtic Farm. (n.d.).

Celtic Farm. (2023, May 28). The Science of Hydration: How Much Water Do Plants Actually Need? The Celtic Farm. Retrieved January 6, 2025, from https://www.thecelticfarm.com/how-much-water-for-plants/

Grammar, B. (2022, July 21). The Science Behind Why Plants Need Water. Commercial Lawn Irrigation. https://www.commerciallawnirrigation.com/blog-posts/the-science-behind-why-plants-need-water

Pandey, D. K. (2021). Soil Moisture. Soil Moisture. Retrieved January 15, 2025, from https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/soil-moisture

Robock,, A. (, 2003). HYDROLOGY | Soil Moisture. ScienceDirect. Retrieved January 7, 2025, from https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/soil-moisture

Science Buddies. (2023). Science buddies arduino board lesson. Science Buddies. Retrieved January 16, 2025, from https://www.youtube.com/watch?v=cd04o5yqSAU&list=PLlBVuTSjOrclb0iCMSRpS_H1lSrlSVeEm

Tremblay, E. (2024, december 23). The 8 Types of Irrigation Systems You Should Know. The 8 Types of Irrigation Systems You Should Know. https://irrigationmontroyal.com/en/irrigation-systems-types/

Water Science School. (2018, June 6). Temperature and Water | U.S. Geological Survey. USGS.gov. Retrieved January 7, 2025, from https://www.usgs.gov/special-topics/water-science-school/science/temperature-and-water

Water Science School. (2018, June 6). Temperature and Water | U.S. Geological Survey. USGS.gov. Retrieved January 15, 2025, from https://www.usgs.gov/special-topics/water-science-school/science/temperature-and-water

WayinTop. (2020). Automatic plant watering tutorial. GitHub.com. Retrieved January 16, 2025, from https://github.com/WayinTop/Automatic-Plant-Watering-System-Tutorial/blob/master/Code/water.py

Acknowledgements:

• Mrs. Summerscales
• Mom
• Dad
• Parker Volk (University mentor)
• Noah Mckinley