Where did you take your soil sample (city, state, and type of area such as garden, yard, by the road, etc.)?

Evaluating Soil Drainage and Soil Texture

Evaluating Your Soil Drainage

The soil in your test area should be damp, neither completely dry nor completely saturated. Dig a hole six inches deep and large enough in diameter to accommodate a 46-ounce metal can (i.e., a large juice can). Remove the top and bottom lids. Set the can in the hole; replace the soil and press it around the outside of the can. Fill the can to the top with water and see how long it takes the water to drain out the bottom.

If the water level drops less than an inch after an hour, your soil does not have enough drainage to accommodate most plants. Either chose plants that tolerate continual moisture, or improve the drainage.

If the water level drops two to three inches after an hour, your soil has good drainage yet will retain sufficient moisture for the healthy growth of many garden plants.

If the water level drops more than four inches in an hour, your soil drains too fast to grow plants other than those that tolerate very dry soil. You will need to add organic matter to help retain soil moisture.

Evaluating Your Soil Texture

Dig six inches into the soil, mix up the loose dirt, and remove any small stones, soil lumps and roots. Fill a wide-mouth quart canning jar half full of the soil. Wet the soil to the consistency of mud. Tap the jar on a flat surface to settle the soil and mark the level of soil on the jar.

Add enough water to fill the jar. A tablespoon of dishwashing detergent will provide a surfactant, which keeps the soil particles separate and gives a more accurate test. Replace the lid and shake the jar several minutes until the soil, detergent and water are completely mixed. Put the jar on a flat surface and let the soil settle out.

When you see three distinct layers, mark the levels on the side of the jar. Sand is the heaviest and will settle out of the mixture in a minute or two. Silt will settle out after about an hour. Clay is the lightest and can take from several hours to a day to settle out of the solution. The clay layer on top will be fine textured and light in color.

Assignment Overview

This activity will allow you to get your hands dirty while learning how to evaluate soil drainage and texture in your garden, neighbor’s field, yard, or where ever you choose.