The hardiest of cereals, rye can be seeded later in fall than other cover crops and still provide considerable dry matter, an extensive soil-holding root system, significant reduction of nitrate leaching and exceptional weed suppression. Inexpensive and easy to establish, rye outperforms all other cover crops on infertile, sandy or acidic soil or on poorly prepared land. It is widely adapted, but grows best in cool, temperate zones.
Taller and quicker-growing than wheat, rye can serve as a windbreak and trap snow or hold rainfall over winter. It overseeds readily into many high-value and agronomic crops and resumes growth quickly in spring, allowing timely killing by rolling, mowing or herbicides. Pair rye with a winter annual legume such as hairy vetch to offset rye’s tendency to tie up soil nitrogen in spring.
Rye is the best cool-season cereal cover for absorbing unused soil Nitrogen (a nutrient “catch” crop) It has no taproot, but rye’s quick-growing, fibrous root system can take up and hold as much as 100 lb. N/A until spring, with 25 to 50 lb. N/A more typical [1]. Early seeding is better than late seeding for scavenging N [2].
A Maryland study credited rye with holding 60 percent of the residual N that could have leached from a silt loam soil following intentionally over-fertilized corn [3]. A Georgia study estimated rye captured from 69 to 100 percent of the residual N after a corn crop [4].
In an Iowa study, overseeding rye or a rye/oats mix into soybeans in August limited leaching loss from September to May to less than 5 lb. N/A [5].
Rye increases the concentration of exchangeable potassium (K) near the soil surface, by bringing it up from lower in the soil profile [6].
Rye’s rapid growth (even in cool fall weather) helps trap snow in winter, further boosting winter hardiness. The root system promotes better drainage, while rye’s quick maturity in spring— compared with other cover crops—can help conserve late-spring soil moisture.
See Also…
“The earth neither grows old or wears out if it is dunged.”
~ Columella, circa 45 A.D.
References
- Legume Cover Crops – Serial Rye
- Univ. of Calif. SAREP Cover Crops Resource Page. www.sarep.ucdavis.edu/ccrop
- Brinsfield, R. and K. Staver. 1991. Role of cover crops in reduction of cropland nonpoint source pollution. Final Report to USDA-SCS, Cooperative Agreement #25087.
- Shipley, P. R. et al.1992. Conserving residual corn fertilizer nitrogen with winter cover crops. Agron. J. 84:869-876.
- Jordan, J. L. et al. 1994. An Economic Analysis of Cover Crop Use in Georgia to Protect Groundwater Quality. Research Bulletin #419.Univ. of Georgia, College of Agric. and Environ. Sciences, Athens, GA. 13 pp.
- Parkin, T. B., T. C. Kaspar and C. A. Cambardella. 1997. Small grain cover crops to manage nitrogen in the Midwest. Proc. Cover Crops, Soil Quality, and Ecosystems Conference. March 12-14, 1997. Sacramento, Calif. Soil and Water Conservation Society, Ankeny, Iowa.
- Eckert, D. J. 1991. Chemical attributes of soils subjected to no-till cropping with rye cover crops. Soil Sci. Soc. Am. J. 55:405-409.
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