A. soil with grass, weeds, or plants (fill with water to top of soil - don't drown plants)
B. soil - same amount of water as A
Weigh your containers. Then, place your containers in a sunny spot. Weigh each container once a day and examine any changes. Use a ruler and measure the water line along the side of each container. Use tape or a marker to show where the water line is and to compare day to day changes. Watch for at least one week. Visit Teach Engineering more details!