While one of the numerous benefits of seeding cover crops is helping solve drainage concerns, a few no-tillers say it has actually created more drainage worries. The concern is that cover crop roots were blocking tile lines.
With last year’s warm fall and winter, along with a very wet spring in the eastern Corn Belt, conditions in some areas were excellent for achieving extensive cover crop growth.
Last spring, cereal rye enjoyed greater root growth than usual and grew as tall as shoulder height in some areas of Indiana. Exceptional growth was also seen with rapeseed, wheat and annual ryegrass seeded as cover crops.
Although cereal rye or wheat would not normally be considered “deep-rooters,” excellent growing conditions in the last year may have allowed them to grow more and deeper roots than typical, says Purdue University agronomist and cover crop specialist Eileen Kladivko.
Ontario educators report cover crop root concerns with clogged tile lines are most likely to occur after a rainy period followed by a prolonged dry period. With limited moisture in the upper soil layer, the cover crop roots grow downward to soak up available water.
While cover crop roots that enter a dry tile line are unlikely to continue to grow, root growth will take off once water starts flowing again through the tile lines in the spring.
Once a cover crop is terminated and the roots dry out, some tile blockages will clear themselves within a month, allowing water to flow…