Question: Does caffeine affect plant growth?

 

Hypothesis: My hypothesis is that the seeds that are watered with coffee will grow faster/bigger than the seeds that are watered just using tap water.

 

The reason why my scientific guess is the caffeine will do better than the water is because it contains a lot of fertilizers and ingredients in it. Water is just H2O, but coffee is H2O but also a lot of other things that help the plant grow healthier and better. Another reason why I think the coffee will work better is that after the beans have sprouted, the caffeine will improve the process of photosynthesis. Potassium and Phosphorus are ingredients in caffeine that help plants to grow faster, so therefore my hypothesis is that watering the seeds with caffeine will improve the growth of the plant. 

 

Research:

1. What does coffee contain?

240 ml of coffee contains:

• Vitamin B2 (riboflavin): 11% of the DV
• Vitamin B5 (pantothenic acid): 6% of the DV
• Vitamin B1 (thiamine): 2% of the DV
• Vitamin B3 (niacin): 2% of the DV
• Folate: 1% of the DV
• Manganese: 3% of the DV
• Potassium: 3% of the DV
• Magnesium: 2% of the DV
• Phosphorus: 1% of the DV

 

The V= dependent variable is a tested and measured variable in a scientific experiment. To elaborate, it means (x or y) that depends on its value based on factors. In this situation, The DV is coffee, and the factors are the minerals in the coffee.

 

1. What does caffeine do to people?

Before we talk about what caffeine will do to plants, let’s talk about what it does to humans. Caffeine reacts as a simulation of your nervous system. When caffeine is in your system, it will send messages to your brain making it to be more awake. Some medications use caffeine to treat any symptom that needs brain stimulation; drowsiness, headaches, migraines, etc. If you have too much caffeine at one time, you will most likely develop headaches. This is because when you drink a lot of coffee at a time, your brain gets used to the coffee stimulating your brain, so when it doesn’t get more coffee, it will start to cause a headache.

 

1. What are the effects of using caffeine for plant growth?

Positive Effects:

• Using caffeine can make the procedure of photosynthesis of plants faster.
• It can make plants look a lot prettier and healthier.
• Cleans a garden full of pests; ground coffee reduces the number of pests eating/ killing the plant.
• Caffeine has potassium and phosphorus which are key ingredients in coffee that help plants grow.

Negative Effects:

• If you use too much coffee, It can also damage your garden and plants. This can be avoided by diluting your caffeine.
• It can turn a plant yellow if there are too many acidic substances in the soil.
• In some experiments, scientists found out that coffee can make the plant cell growth at first, but some plants the caffeine begins to kill the plants.

 

1. What benefits are there from using coffee to grow plants?

• Coffee beans have a lot of calcium, copper, magnesium, carbohydrates, and many other vitamins inside.
• Coffee beans contain nitrogen, which is the function of sunlight being changed into energy. Potassium; moisturizes plants through photosynthesis. Phosphorus; helps energy enters through the roots and cells of a plant which is essential for fertilizer.
• Waste of caffeine with fertilizer prevents pests from plants. 

 

 

Investigation Plan:

1. Buy the Mung seeds
2. Soak Mung beans in water for 12 hours
3. Fill the containers with dirt
4. Put seeds in dirt
5. Water one of the plants in coffee, and one with water every week
6. Record data

 

Materials:

• Plastic containers
• Coffee
• Mung bean seeds
• Water
• Soil 

 

Recording Equipment:

• Phone
• Pencil & Paper
• Ruler

 

Safety concerns or risks:

Watering a plant with coffee sounds really easy. You just water the plant and the result will probably be better than water because coffee has nutrients right? Not quite. Coffee is very acidic, and plants will not be healthy if the soil is too acidic. So, it’s better to not water plants that do not like acidic soil in it at all. The risk is that maybe the mung beans that are being watered by coffee might die if we are not careful with the amount of caffeine in the coffee. Other than the plants, nothing else seems to be at risk. 

 

Ethical and Environment issues:

The ethical and environmental issues are that in the future our water maybe won’t be fresh anymore, and maybe when that happens, we could use another alternative. We wanted to use greywater before this, but another group decided to do it so then we had to think of another water substitute. After research, we found out you can water plants with coffee and that it can benefit the plant if used well. We thought maybe if the coffee can benefit our plants more, then it could be a very good substitute for water and be even more beneficial towards plant growth. 

 

Data:

These charts show the amount of growth of the plants throughout 15 days. The blue chart indicates water, and the orange indicates coffee. The x-axis is the day numbers and the y-axis is the cm it has grown.

Our original way of recording our experiment was using a pencil, paper, and a ruler. It is a chart that shows the day, and the cm grown in both plants. 

 

 

 

 

 

 

 

 

 

 

 

 

 

We also took pictures of the progress. It is in a docx because there are a lot of photos to show. 

Click here to see photos of plant growing process 

 

Analyze:  

The relationship between watering the beans with water, and watering them with coffee is that they are both liquid substances being poured into the body of soil. Water is H20 and coffee also contains H20 since we had to add water to the coffee powder to make it, while also containing several other minerals. Even though coffee contains several more dependent variables, in our experiment the plant that was watered in water surpassed the growth of the plant that was watered in coffee. But that doesn’t mean all plants will react the same since this is just one certain type of plant.   

The inconsistency I saw was that through day 1-3 the plants seem to be at the same growing speed. But when I checked on days 4 and 5 the water grew more and the coffee one was a faded green instead of light green. I also saw that near day 6 the roots of the coffee plant were started to grow out of the plant above the dirt even though they are supposed to have stayed under the soil. It might be because there wasn’t enough dirt but this did not happen to the water plant so it was very abnormal. 

 

Conclusion: 

Part 1:

Our hypothesis was that coffee was going to make the plant grow faster, more leaves, and better overall. Well, the experiment proved us wrong because as you can see from the pictures above, the bean plants that grew more and bigger were the plants that were watered in water. Although the coffee plant did last longer than the water plant. So, therefore, our finding did not support our hypothesis, even though it could’ve been the new way of watering plants that could do more than feeding the plant H20. 

 

Part 2:

In conclusion, water is still the better liquid to water your plants with. Over the past 2 weeks, plant 1 has grown surpassing plant 2 and it was very consistent until the end where plant it started to shrivel up and started to die off. After day 13, plant 2 was still healthy-looking while plant 1 was nearly in its death bed. Even though the coffee lasted longer than the water doesn’t mean it’s better. If you had to grow crops I don’t think I would recommend it because we didn’t test this to eat, so we don’t know if it is better for crops or not. All I know is that the coffee plant changed a different shade than the water plant and I do not know what reason caused that to happen. So if you want to be safer, I’d say watering your plant the traditional way with water is the best idea. 

 

Part 3:

One uncertainty is that bean plants are actually pretty easy to grow. They don’t really need sunlight or soil. You could plant then in a paper towel and they would still grow. The reason why we chose to use mung bean seeds is that they grow really fast and we needed a fast-growing plant for this experiment. So, therefore, it wouldn’t be super accurate because not a lot of plants are like mung beans and are super easy to grow. Bean plant wise, coffee does not benefit bean plants much, but I can’t speak for other plants. 

Confusing variables involve the growth of the roots in the plant that was watered in coffee. The water plant wasn’t that much longer than the coffee, but you could tell that the roots of the coffee plant were a lot more than the roots of the water plant. Another confusing variable was that the plant that was watered in coffee stayed alive longer than the plant that was watered in coffee. My guess is that maybe the coffee slows down the growth of the beans, which makes them last longer than the one watered in water, or that the coffee includes some type of fertilizer that helps the plant stay alive longer.

In every experiment, comes with a lot of improvement spaces. I think our quality of data was pretty decent considering our experiment is just to compare the growths of the two plants. Ways that we could’ve improved was to discuss the data collecting even more because it took us a long time to figure out how we’ll keep track of our data. Communication is also a way we could’ve improved on. We talked about our experiment sometimes, but I think we could’ve discussed more about this project outside of school. The last way we could improve the quality of data as if I kept track of the plant every day. Since I was the one who was responsible track the data and take photos, I could’ve checked on it every day (because mung beans grow fast) but instead I chose to collect data from day 1-4 then stared collecting data every 2 days after that until day 14 and 15.