What Kind of Soil Is Best for Water Retention?

Soil structure determines how well it will retain water.

Soil retains water depending on its organic composition with heavier soils retaining water more easily while lighter soils drain quickly. Gardeners prefer soils that are of medium weight for balanced aquatic retention and drainage.

Heavy Soils

These soils are composed primarily of clay, which have small particles that bind together easily. Clay has more pore spaces, making it hold onto water more tightly. This same property, however, makes clay soils water-logged.

Medium Soils

Often called loam or silt, this soil type also has slightly larger pieces, which also retain water well. But because the pores are larger, this soil drains better, which gives plants an ideal reservoir for nutrient and water uptake.

Light Soils

Light soils are constructed of sand, chalk, peat, or a combination of the three. Particles are large and can be blown away easily as well as allowing water to drain quickly.

Climate

Air temperature and ambient humidity also affect water retention in soil. Cooler temperatures and higher humidity help soil retain water. Long, hot sunny days promote evaporation no matter what the soil type.

Amendments

Soil may be modified to make it more amenable to water retention. Humus may be the most beneficial additive as it has a light, open structure that holds air and drains well. Peat is another additive that may be used to improve soil structure and water retention, although it should not be used on light soils.

References

• The seed site: Soil
• Natural Resources Cornell Cooperative Extension: Water and the Soil

Resources

• Rain: Soil Types and Testing