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Cereal rye cover crop analysis

Article cover photo
The On-Farm Network is in the process of analyzing yield results from fields planted to cover crops. Joseph Murphy/Iowa Soybean Association

By Scott Nelson, ISA On-Farm Network director

Over the past three years, the On-Farm Network has collected cover crops research from more than 100 locations. Various species and blends of cover crops were compared to no-cover strips as part of replicated strip trials. Most of these trials were conducted by first-time, novice users of cover crops. Recently, yield responses of soybeans and corn to fall planted cereal rye were analyzed.

The average effect of cereal rye cover crop on soybean yield was 0.3 bushels, not significant in our analysis. Locations responded differently to cereal rye with some locations realizing a 3 bu/A yield advantage. Understanding why these locations responded positively to cover crops is very important for making cover crops profitable in the short-term. This understanding involves an on-going effort, but for now data shows it was partially due to better stand establishment in the residue for the higher yielding areas.

Figure 1. Yield advantage/disadvantage for soybeans planted into cereal rye cover crop.

A common misperception is that corn planted into cereal rye is naturally lower yielding. In our analysis, when yield responses were averaged across all locations, there was no difference in yield between corn planted into cereal rye or no cereal rye (Figure 2).

Individual locations did seem to respond differently to cereal rye, but most locations showed a small yield advantage. Locations responding negatively to cereal rye could have been due to planting problems in managing the residue, nitrogen immobilization or unknown factors. Locations showing a positive response to cereal rye signifies the potential for cereal rye cover crop to be profitable in the short-term. Regardless of location differences, the results indicate there is no inherent yield disadvantage for planting corn into cereal rye.

Figure 2. Yield advantage/disadvantage for corn planted into cereal rye cover crop.

The locations in this analysis involved fields with no history of cover crops and novice users. Anecdotes from farmers are that yield responses to cover crops become greater with constant cover cropping over time. These claims remain to be verified with on-going research. There were no large yield disadvantages for cereal rye with novice users. This means cover cropping with cereal rye is a stable system in terms of yield with large benefits for control of erosion and other yield limiting factors.

For media inquiries, please contact Katie Johnson, ISA Public Relations Manager at or Aaron Putze, ISA Communications Director at

For permission to republish articles or to request high-res photos contact Aaron Putze at Iowa Soybean Association | 1255 SW Prairie Trail Pkwy | Ankeny | IA | 50023 | US

©2018 Iowa Soybean Association On-Farm Network®. All rights reserved. On-Farm Network® is a registered trademark of the Iowa Soybean Association, Ankeny, IA.Portions of some On-Farm Network trials are paid for in total or in part by the soybean checkoff.

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