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Yield Increases With Crop Rotations

Dec 30, 2013
By Shawn Conley,
 
Sevie Kenyon: You’ve been doing a long-term study with rotations. Can you describe for us what you’ve seen?
 
Shawn Conley: Since the advent of time we’ve known that crop rotation is good. However, there has been this “crop rotation effect” that’s unexplainable, and that’s what we’re trying to figure out.
 
Sevie Kenyon: Maybe you can define for us what a crop rotation is.
 
Shawn Conley: What a crop rotation would be is if you switch the crops from year to year. So any field you’d have corn one year, the following year you’d put soybean in that field. So again it’s a mechanism in order to change the crop from year to year, to increase yield.
 
Sevie Kenyon: What are some of the benefits you’ve found to the rotation effect?
 
Shawn Conley: The rotation effect really greatly increases yield, and one of the challenges we always run into with today’s economic prices is that the numbers have basically told growers, “Plant corn, plant corn, plant corn”. What we’ve found is just by adding soybean into the rotation, what we’ve been able to do is actually increase our corn yields. Then when we start adding an additional crop in such as winter wheat, what that actually does is then it benefits our soybean yields. As we diversify that cropping system by adding more and more crops in, we begin to increase soybean yield, and also improve and change the pest species complex in that system.
 
Sevie Kenyon: And Shawn, your most recent study, what parameters did you look at?
 
Shawn Conley: Well, with today’s molecular techniques, we’re able to go in and pull some soil samples and extract DNA right out of the soil. And what we can do is determine what are some of the pathogen species. In this case we’re focusing in on the fusarium species, which would be stock rock corn, it would be seedling blight and soybean, and fusarium head blight or scaven winter wheat. These species move from crop to crop. And by understanding that cropping sequence, when you should plant one crop following the other, can we not only increase yield, but also decrease the amount of that disease complex in the system for the following year’s crop.
 
Sevie Kenyon: Have you got enough information to offer some advice to growers?
 
Shawn Conley: We have corn/soybean rotations while well established, by adding wheat into that cropping system we really enhance soybean yield and growers have been struggling with maintaining high soybean yields, and a lot of it has to do with soil born pathogens. By adding that wheat into the system, we can really increase soybean yield by basically two to three bushels, which is fairly significant. One of the advantages we have living in the state of Wisconsin is our dairy system. So we have a place for that wheat to go, and then that land can be open for manure applications. So these dairies need someplace to haul manure. In terms of the environmental system it works very well. We’re hauling manure in the summer, so the rotation works very well.
 
Sevie Kenyon: We’ve been visiting with Shawn Conley, Department of Agronomy, University of Wisconsin Extension and the College of Agricultural and Life Sciences, Madison, Wisconsin, and I am Sevie Kenyon.
 
Source: uwex.edu