|How can I determine what is the right soil moisture for growing plants in a 2 liter bottle for a biology project? In the procedure it says something about testing the pH level of the soil? I'm don't know how to do that. Is it really important for this experiment?|
|First of all, the type of plant you are growing will, in part, determine how moist you need to keep the soil. Generally, it's a good idea to keep the soil evenly moist, but not soggy. In an enclosed space like a bottle, you may need to water less frequently than an open container--however, that's all part of the experimental process! Be sure you provide some sort of drainage--like a layer of gravel or styrofoam pieces in the bottom--so that the soil can drain.
As far as determining pH--I don't know what experiment you are performing, so I can't say for sure. The pH, or relative acidity, of the soil does affect plant growth. Can your teacher help you find a pH test kit, perhaps from your schools chemistry department?