Fall Control of a Red Clover Cover Crop

A beautiful stand of red clover can provide as much as 75 kg of nitrogen per hectare (when at 40 cm tall) for next years corn crop. However, if the clover crop is not "killed off" in the fall, then preparing a suitable seedbed to plant next years crop in is often significantly delayed resulting in reduced yields. A review of different strategies to control red clover in the fall is presented below.

When is the best time to retire the red clover stand?

A research project conducted by Dr. Steve Bowley (University of Guelph) demonstrated that red clover gains significant root biomass during the month of October. Therefore killing off the stand in September could be short changing your nitrogen credit for next spring. Results of Dr. Bowley's study are nicely summarized in this short 10 min presentation (http://fieldcropnews.com/2012/08/when-is-it-time-to-retire-your-red-clover-cover-crop/).

Managing options for red clover

Fall ploughing is the only effective tillage operation for managing red clover (Figure 1). Less aggressive tillage options (e.g. chisel plough - Figure 2) are much less effective in controlling red clover the following spring.

Figure 1. Control of red clover in the spring following fall tillage with a mouldboard plough.

Figure 2. Control of red clover in the spring following fall tillage with a chisel plough.

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