Gravitropism

Overview

The original question for my project was; which soil type (Rocky/gravelly. sandy, Clay, potting soil, or silty soil (fill dirt)) will allow a plant to best exhibit gravitropism? Through my research, I learned a lot about light capture and growth hormones in plants, as well as the other tropisms and about how different soils and environments affect the plant. After this, I hypothesized that the silty soil would allow the plant to exhibit gravitropism the best, because I thought that it would have the capability to retain the moisture and nutrients given, while not restricting the soil too much. I cleared out my closet to give a controlled space for the plants to grow, and I put a grow light in with them. I positioned the grow light in between the controls, which were on the ground, and the tested plants, which were hanging from above, so the tested would only receive light from below, semi-eliminating phototropism, and the controls only received light from above. I allowed all of the plants to germinate and receive their photosynthesizing leaves prior to flipping them so that they wouldn't try to actually turn and grow out of the bottom of the cup. When they were all ready for flipping, I put padding in between the soil line and the top of the cup, then put Glad Press and Seal over the top, cutting holes for the plants to grow through, then I put the cup on top of wooden slats, allowing the plants to grow between those slats. Then, I let the plants grow for two weeks, before cutting the cups open and observing the root growth, as well as the stem growth. Gravitropism was very clearly exhibited in soil type 3 and 4, the clay and potting soils. The roots turned and grew above the soil line, into the padding. The silty soil turned out to be very restricting, as the soil packed down hard and prohibited growth. Drainage was a big problem, and many of the plants in especially soil type 5, silty soil, drowned. My final conclusion was that the potting soil was the best, because it retained moisture and nutrients, while allowing the plants to grow and adapt to their new environment.

Competition history

• CSEF 2026 Plant Biology (Junior Division) · Entry J-18-04

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

• All Plant Sciences projects
• CSEF Plant Sciences projects
• Every CSEF 2026 project