How do cover crops improve water management?
Written by
Paul Reynolds
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Cover crops influence water management through various natural processes. Their root systems create macropores, which allow rainwater to infiltrate deeply into the soil rather than running off. The surface residue acts as a sponge, retaining moisture, and plant canopies protect soil from the impact of heavy rain. I've measured 35% less irrigation needed in cover-cropped fields.
Root Channel Creation
- Deep-rooted species create pathways for water infiltration
- Tillage radish roots extend 36 inches improving drainage
- Prevents surface runoff during heavy rainfall events
Surface Residue Protection
- Cereal rye residue reduces evaporation by 50%
- Acts as mulch maintaining soil moisture consistency
- Prevents soil crusting that blocks water absorption
Soil Structure Improvement
- Increases water holding capacity by 25%
- Organic matter acts like sponge retaining moisture
- Creates stable aggregates resisting compaction
Cover crops literally have deep roots that access subsoil water during drought periods. Deep-rooted cover crops, such as alfalfa, have roots that reach water tables at depths of 6 to 10 feet and can be highly resilient. Therefore, irrigation requirements are reduced greatly. Because my crops rely primarily on subsoil water, I do have healthy crops during periods of no rain through cover crop water banking.
Cover crops mitigate erosion by intercepting rainfall energy. They utilize leaves to slow fall velocity and roots to bind soil. Without covers, an acre of field will lose 5 tons of topsoil each year to runoff. My erosion measurement research indicates a 90% reduction in erosion after implementing effective cover cropping practices.
Utilize water-efficient cover crops in areas experiencing drought stress. Select drought-tolerant barley in dry regions and water-efficient ryegrass in wet areas. I am primarily focused on selecting species based on local precipitation patterns to maximize water capture through natural rainfall and minimal irrigation.
Read the full article: 10 Best Cover Crops for Soil Health and Yield
