Put in separate jars with lids and label. Add same amount of water to each. Shake, and leave to settle. Look at layers, turbidity etc to see components and properties of different kinds of soil. Observe growth, life cycle, habits, feeding, role in ecosystem.
Frogs are a barometer of the health of an ecosystem.
Species of frogs can survive in a desert. Listen to calls. Identify different species by sounds they make. Contribute to research via E-mail. Plants - Grow broad beans, compare with wheat grown in garden enclosure, compare leaf, root structure, rate of growth etc.