Water is an essential soil component, especially from a plant’s perspective. Though plants require air and water found in soil pores, roots can only absorb nutrients from soil water. Dissolved nutrients in solution establish equilibrium between the soil water and the soil particles and organic matter.
Sandy soils are often better drained than more clayey ones because of the larger pore spaces between particles. This also creates lower nutrient availability for plant roots. The small pore spaces in clayey soils attract and hold more water against the pull of gravity, making them slower to drain. However, this also makes a better environment for available plant nutrients.
Soil health is the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans. Remember: soil contains living organisms. These organisms require the basic necessities of life to survive. Food, shelter and water are necessary for soil to produce valuable food and fiber.
While soil isn’t a moving, growing medium, it is teeming with life. Billions of bacteria, fungi, and other microbes call soil their home. These organisms are the basis of a strong, symbiotic ecosystem—and water is an extremely important part of that ecosystem.
Soil can be managed to:
- Provide nutrients for plant growth, absorb and hold rainwater for use during dryer periods.
- Filter and buffer potential pollutants from leaving fields.
- Serve as a firm foundation for agricultural activities.
- Provide habitat for soil microbes to flourish and diversify to keep the ecosystem running smoothly.
Conservation agriculture systems can help minimize soil surface disruptions. Cover crops help protect soil surfaces and increase organic matter in the soil. Use of conservation tillage practices and cover cropping improve water use efficiency by increasing the amount of water which infiltrates into the soil. Soil water storage capacity also increases. The soil stores this water until crops need it. Cover crops can also reduce water losses through evaporation and transpiration.
For more information on improved water use and storage, visit https://www.ars.usda.gov/ARSUserFiles/60100500/FactSheets/FS06.pdf .