Lab Report IA: How will different soils affect rate of bean plant growth?

[freshfaced333]

Hi guys, for my IA, I have decided to investigate how clay soil, silt soil, and pure fertilizer can affect the rate of growth of a regular bean plant. The thing is, I'm really not sure if this is a good topic? Does this count as only changing 1 variable (soil)? My teacher Okayed the topic, but I'm having second thoughts. I'm planning to plant a total of 20 seeds, with different soils for every 5 pots. (So 5 pots clay, 5 pots silt, 5 fertilizer, and 5 regular garden soil)

 

I'm confused as to how I should form my hypothesis also!

 

thanks

[anotheribkid]

We did something similar to this last year, but I think I looked at how the pH of the soil affected the plant's growth. This seems like a reasonable experiment, but for you hypothesis you might want to do some research into the minerals in each and then based on that, create a hypothesis so you cover the 'scientific reasoning' part of the hypothesis. 

[freshfaced333]

thanks for the reply! I actually changed it to how different concentrations of fertilizer can affect the rate of plant growth.. I experimented with the different soils procedure over the summer and it failed.. haha

 

I just cant seem to find other examples of my new topics... it seems like no one ever measures the concentration of fertilizer? most people go the pH route, or the different colored cellophane option

[bobbywhite]

sounds good but what were your variables and methods