Tag Archives: Steve Berger

Cover Crop Root Growth – Annual Ryegrass

Steve Berger did a trial of annual ryegrass this past winter. It was ideal soil, having been in no-till for 25 years. On one plot he planted cereal rye; on the other he compared the growth of four annual ryegrass varieties.

Iowa has lagged behind other Midwest states in adoption of cover crops. Berger’s farm, in SE Iowa, is an ideal place to test it out. In that respect, Berger is an early adopter for trying annual ryegrass.

The winter was unusually mild and, thus, all the annual ryegrass did well, as did the cereal rye (a grain, not a grass). The surprising thing, when he did a root depth analysis…the cereal rye roots went deeper into the soil than annual ryegrass. Usually, on poorer soils, the opposite it true: annual ryegrass roots sometimes go as deep as 60 inches over the winter, while cereal rye roots are much shallower.

Two theories. One, annual ryegrass roots seek nutrients and moisture. On the Berger farm, there was plenty of nutrients and moisture in the no-till soil, thus they didn’t need to work overtime to get nutrition. Secondly, he did the tests in early April, a couple weeks earlier than usual. Perhaps a couple more weeks of root growth would have added more root depth.

Another thing to consider in the next year…whether cover crops tend to do better after corn or soybeans. Corn is more demanding of nitrogen, and thus the amount of available nitrogen in the soil might impact the growth of a following cover crop, especially if nitrogen was not added.


Annual Ryegrass Cover Crops in Iowa – Field Day on March 30th



March 30TH – 10 a.m.

Steve Berger Farm, 1267 Elm Ave., Wellman, IA

Field  plot site is one-half mile North at Elm Ave & 120th St.

Topics:  Benefits of Cover Crops – Reduce erosion – Nitrogen credit for next crop – Build organic matter              

Iowa Grower Builds Soil, Stabilizes Organic Matter Losses with Cover Crops

Iowa Grower Builds Soil, Stabilizes Organic Matter Losses with Cover Crops

Going to No-till in the late ’70 helped reduce loss of organic matter,” said Iowa grower Steve Berger, “but adding cover crops in the past decade has really made a difference. “The organic matter present in the fence rows is between 5% and 6% but less than 4% in the fields. With cover crops, we have stabilized the losses we continued to see in our soybean rotation.”

Boosting organic matter is important, but Berger says these other things are more easily accomplished and witnessed:

  • Better, “mellower”, soil structure
  • increased microbial action
  • more root channels for corn roots to follow
  • the soil’s “bulk density” is down
  • infiltration rate of precipitation is up
  • soil erosion on his rolling, terraced fields is reduced

Berger has used cereal rye as a cover crop pretty consistently but tried annual ryegrass about five years ago because of its deeper rooting and its ability to soak up and store nitrogen for use during the next crop season. “That’s important, especially in wet years,” he said, “because annual ryegrass will cycle nutrients and keep them from being flushed out of the field through the tiles.”