Farm Horizons, May 2009
Rolling soybean fields
By Dave Schwartz
New technology in crop production is coming to us at a faster rate now than ever before.
Think about the changes we have seen in the past few years auto steer, corn rootworm resistant corn, foliar fungicide application on corn and soybeans, strip tillage, deep banding fertilizer, use of row cleaners, etc.
These innovations have greatly changed the way we manage corn and soybeans.
I have had a number of questions this winter on roller/packers that are used at planting time to level fields, so I thought this might be a good topic to address in this article.
From what I know, many growers have rented rollers ($3.50 to $4 per acre), rather than investing approximately $30,000 for a new machine. In most cases, growers have been pleased with the results.
To find out if any research has been done on rolling, I checked with a former co-worker of mine, Jodi DeJong-Hughes, who has done extensive tillage research with the University of Minnesota.
She headed up a team this past year that looked at the value of rollers at four different locations in Minnesota, including Albertville. They rolled fields at different stages of growth pre plant, post plant, cotyledon, first trifoliate, and third trifoliate. Researchers measured plant populations, erosion potential, estimated residue coverage, harvestability, and yield.
Their findings are summarized below:
• Crop residue appears to protect plants from rolling.
• Rolling beyond emergence induced more plant damage.
• Rolling did not significantly change yields and stand counts.
• Rolling increased potential for sealing the soil surface.
• Harvest was less stressful with rolled plots.
From what I have observed, fields are much easier to combine, and this may be the key reason why growers are so positive about rolling fields. Rocks are compressed into the soil, and therefore are less likely to be picked up and carried into the combine.
I would caution growers about rolling fields after plants have emerged. From a plant health standpoint, this would appear to set plants back and delay maturity.
I also wonder what the erosion potential is when rolling hilly fields. Jodi and her team plan to do more research this coming year so it’s possible their research will help answer these questions.
When I look into my crystal ball for 2009, I see better soybean yields than this past growing season. We had several negative events stacked against our 2008 soybean crop that should improve in 2009.
Have a good year!