Extension Ag Update
September/October 2004
Articles Research Resources Internet Links Ag Facts Education

Soybean Yield as Affected by Biomass and Nitrogen Uptake of Cereal Rye in Winter Cover Crop Rotations

Matías L. Ruffo, Donald G. Bullock and Germán A. Bollero* , Department of Crop Sciences, Univ. of Illinois, 1102 S. Goodwin Avenue, Urbana IL 61801

The inclusion of cereal rye as winter cover crop following corn has been suggested as a valuable nutrient management tool in the typical corn–soybean rotation of the U.S. Midwest. However, little information is available on the effects of rye winter cover crop on the soybean crop. A study was conducted to quantify biomass and nitrogen uptake of rye winter cover crop and to evaluate the effect of rye winter cover crop on soybean yield.

The effects of four rotations (corn/soybean, hairy vetch–corn/rye–soybean, rye–corn/rye–soybean, and hairy vetch + rye biculture–corn/rye–soybean) on soil residual nitrogen content, rye biomass, soil residue cover, soybean light interception, and grain yield were investigated at Urbana and Brownstown, IL.

Rye nitrogen content was highly correlated with soil residual nitrate content (r = 0.64, p < 0.0001). Rotations that only included hairy vetch (Vicia villosa L.) reached maximum nitroogen content at lower corn nitrogen rates compared with rotations with rye. Soybean light interception at R1, R4, and R6 growth stages and grain yield were not affected by the treatments. Rye winter cover crops planted after corn appears to take up a significant proportion of residual nitrate without affecting soybean grain yield, providing an environmental service to the agroecosystem.