What happens to the way plants grow if there are no microorganisms in the soil?
Take a sample of fertile soil from a field or garden and divide it into two portions. Bake one in an oven (to destroy the microorganisms). Leave the other portion alone as a control. Plant the same number of seeds in each soil sample. Remember to treat both samples the same while the plants are growing. Make sure all the plants receive the same amounts of water and light, and are kept at the same temperature. How do the plants differ as they grow? Are different plants affected in different ways by specific microorganisms? Some microorganisms and plants form mutually beneficial partnerships. For example, certain bacteria make a natural nitrogen fertilizer for plants in the family called legumes. Peas, alfalfa and soybeans are legumes. The nitrogen-fixing bacteria are available from garden supply stores and by mail order. Grow both legumes and non-legume plants with and without the bacteria. Are there differences in how well the plants grow?
