COVER CROP RECOMMENDATIONS

Here are tips for keeping biomass low and for managing corn following cover crops:

1. If new to cover cropping, consider starting with spring barley or oats (covers that will winterkill in cold climates).

2. Keep seeding rates low for covers that survive the winter (such as 60 lbs./ac or less for winter rye).

3. Wait 10 to 14 days between termination of winter rye and corn planting.

4 Ut ilize a starter fertilizer that contains nitrogen.

5. Us e row clear attachments on plant- ers to increase soil warming around the seed.

6. Split apply N fertilizer, or at least avoid having all of the nitrogen applied in-season.

The following are considerations for when you get more than 2,000 lbs./ac of winter rye:

1. If a lot of biomass has already been produced during a warm fall, consider a fall termination to avoid excessive biomass in the spring.

2. Terminate the winter rye as early in the spring as possible and make between 2011 and 2019. (The report can be found at www.practicalfarmers.org.) These studies by PFI were conducted with cooperating farmers on their fields. Collectively, this indicates that there is some potential risk to corn yield when winter rye biomass gets too high, but experience with cover crops can reduce the overall risk of yield loss.

Grass cover crops take up nitrogen from the manure that would have likely leached out of the root zone over winter and spring before planting. However, it does appear to tap into the nitrogen that would typically be available for that next corn crop. The trick for farmers is to grow enough cover crop biomass for good erosion control but not grow too much as to tie up nitrogen. See the sidebar for recommendations. ■ fields with an abundance of winter rye biomass top priority in the spring.

The author is a professor in the department of soil science at the University of Wisconsin-Madison.

3. Consider harvesting the winter rye as a winter silage crop. This would also be beneficial from a nutrient management planning perspective, as the nutrients from the fall manure application would be applied to this winter silage crop. If interested in this option, it will also be important to follow all herbicide rules, as some applications can prevent the winter rye from being fed.

4. If you want to avoid risk, consider planting soybeans instead of corn.