|My daughter is trying to outline an experiment for science class (10th grade). She would like to test the effect of various chemicals on new seedlings as they grow. Can you suggest several easily procured chemicals to add to the soil which would both help and/or hinder growth and development?? Suggestions on good plant species or seeds to obtain for this experiment would also be appreciated.|
|One way to approach this is to try to mimic various environmental factors. For example, treat plants with a vinegar (or lemon juice) solution to mimic acid rain; with vegetable or motor oil to mimic an oil spill; with salt water to mimic road salt spray.Can you think of any other environmental conditions you could explore? You can test these substances in various concentrations, and apply them in various ways (spray on leaves, apply to soil, etc.)
Another experiement would be to test various fertilizers, or even fertilizer components, to see which affect plant growth. The school's chemistry department may be able to set you up with the chemicals used in commercial fertilizers for supplying nitrogen, potassium, and phosphorus, for example. Youcould then study the effects of nutrient excesses and deficiencies.
Whatever experiement you do, choose plants that are easy to grow. Beans are a classic "classroom" plant; you might choose a flowering plant like marigolds, especially if you are studying the effects of nutrients. Even something like lawn grass planted in flats can be a very effective choice. I hope this is helpful!