The Effect Of Fertilizer on the Growth of Tomato Plants
I was having trouble growing tomatoes in my backyard. I wanted to make the larger, so I decided to try to use some fertilizer. Before I put it on all of my tomato plants, I wanted to see if the edition of the fertilizer would actually make a difference.
Problem: Tomatoes were too small
Question: Will adding fertilizer increase the size of my tomatoes?
Creating a hypothesis for my experiment:
Once I have the question, I need to develop a hypothesis for my experiment. We always want to have the hypothesis to be in the form "If the independent variable, then the dependent variable." So, we need to figure out what those would be.
Independent Variable: Fertilizer
Dependent Variable: Size of Tomatoes
Hypothesis: If fertilizer is added, then the tomatoes will grow larger
Procedure:
- Get 60 seeds of same species of tomato
- Plant seeds in part of yard where they have same type of soil and get the same amount of sunlight
- Apply fertilizer once a week to half of the plants
- After tomatoes have ripened, take the mass of each tomato and record if it were in the experimental group or control group
Results:
The tomatoes grown with the fertilizer averaged 34 grams, and the tomatoes grown without the fertilizer averaged 30 grams. The tomatoes did grow larger with the addition of the fertilizer.
Discussion
The fertilizer helped grow not only larger tomatoes, but also larger tomato plants all around. Fertilizers contain nitrogen and phosphorus that are typically limiting factors in the growth of plants. When these elements are added to the soil, the plants are able to grow larger.
To ensure the results in the experiment were only from the addition of the fertilizer, I needed to make sure conditions were the same in the experimental and control groups. I used the same species of tomato, made sure both groups recieved the same amount of sunlight and water, and had the same soil conditions. Because one half the garden was used for the control group and the other half of the garden was used for the experimental group, it may have been easy for these conditions to be changed.
For additional experiments, I could expand my findings in several ways. I could try different amounts of fertilizer to see if there is an optimal amount. I could also try to see if different species of tomatoes have the same results. I could also investigate whether different brands of fertilizer would also show the same results.
Conclusion
Adding fertilizer to tomato plants will increase their growth. When all other conditions were the same, tomato plants grew 13% larger when fertilizer was used.