Damaged Soil

The goal of our group was to test and find what pH level is best for lima beans to grow in. In order to make the soil more acidic, we added soil acidifier to make, and to make it more basic, we added lime to the soil. We used pH levels ranging from 4-8.4.

We concluded from our background research that the most growth would occur in a pH level of 5-8. We also stated that no growth would occur in a pH level of 4.0 and below or 9.0 and higher. We figured this because the pH level that most plants grow in a soil pH of 5-6, so we thought we could give or take a few points either way. To set up our lab, we first got 18 pots and filled them with soil, two lima beans in each one. We watered the plants daily and also measured and recorded them two or three times a week. 

As we predicted, there was no growth in the pots with the pH of 4.0 or 9.0. They both were too much acid or base for the plant to grow in. We were right about the plant growing in a pH of 5-8, but the strongest growth was in the pH level of 8. We concluded that the best pH level for a lima bean to grow in was 8-8.4.

    When we predicted the lima beans would grow best in a pH level of 5-6, we were wrong.  We figured that the lima beans would be no different than any other plants, but they were.  They grew best in a more basic pH level.  If we would have had time to do this project a few more times, we would probably have found that the lima beans grow in a more basic pH level, just not as high as an 8-8.4.  After our we finished our observations, we were curious about the normal pH level of soil for lima beans.  We researched this and found that they do grow better in a higher basic level, but not as high as our results.  They grow best in a range of 7.2-7.8.  If had the opportunity to do this project a couple more times, I'm sure the pH level of the soil would have averaged in between 7.2-7.8. 

Abstract	Introduction
Hypothesis	Materials
Set-up	Procedure
Observations	Results/Conclusions