Science Buddies: "Ask an Expert"

I have six small pots of poppies. We are using chippings and powder iron. The poppies are doing just fine. In fact I have them on a ledge and are growing twards the light.

Hi Mackenna,

I'm still not sure what your question is, but it sounds like you are testing the effects of difference sources of iron or different concentrations of iron on plant growth. Iron is an essential nutrient for plant growth and is used in enzymes required for respiration. However, as with all nutrients, it is possible to have too much or too little iron. You should have a control pot of poppies that don't have any iron added, and then hopefully, you are adding a measured amount of iron to each of the other pots. The light, water, temperature, and other growing conditions should be identical (controlled) for all of the pots.

In a science fair project, you need to measure results. Are you measuring the plant height, the number of leaves, or something else? You will probably want to graph the quantitative result vs. time on a graph for your board.

The pH of the soil is important for iron adsorption. Most plants can use iron best at a slightly acidic pH. If the pH of the soil is too high, the iron becomes insoluble and the plant will show signs of iron deficiency, even though there is plenty of iron in the soil. It might be helpful if you could get some pH paper and measure the pH of the soil in each of your pots.

I hope these general comments will be helpful. Please let me know if you have questions about completing your project.

Donna Hardy