Experiment with which types of soil absorb the most water. Procure samples of potting soil, beach soil, mountain soil and backyard soil. Measure the mass, volume and density of each sample. Place samples in a pot with drainage and pour equal amounts of water on each sample. After the water has been absorbed by the soil and excess water has drained, reevaluate the mass, volume and density of each sample to calculate which absorbed the most water.
Test how plants grow in moderately coarse soils with a variety of moisture contents. If you don't have access to a moisture sensor probe, estimate the moisture content of the soils that you use. If you squeeze soil and it leaves a wet outline on your hand, it has an approximate moisture deficiency of 0 percent. If the soil forms a weak ball that breaks apart easily, it is approximately 25 percent deficient. If the soil will form a ball but falls apart when bounced, it is around 50 percent. If the soil is crumbly and barely forms a ball, it is around 75 percent deficient. If the soil is completely dry and loose, it has a deficiency of 100 percent.
For this science project, the student seeks to discover if organic material affects the amount of moisture that soil absorbs. To perform this experiment, procure equal amounts of potting soil, sand, manure and peat moss. Evaluate the amount of organic material in each sample. Create different mixtures with varying amounts of each soil and place in pots of the same size and style. Keep the soil in the same room and add equal amounts of water to each pot. To test results, measure the amount of water that drains from the soil 12 hours after adding the water.
Experiment with how much time soil needs to absorb water. Set up five identical samples of soil in a pot with drainage. Measure the mass, volume and density of each sample. Use a timer and a bottle to steadily drip an equal amount of water into each sample. Vary the speed and interval of the watering with each sample. Weigh each sample at the end of the experiment to test which method allowed the soil to absorb the most water.