Erin Silva: science of organic field crop production

Erin Silva, Associate Scientist
Department of Agronomy
UW-Madison College of Agricultural and Life Sciences
emsilva@wisc.edu
(608) 890-1503, (608) 262-1390
The science of organic crop production
3:24 – Total Time
0:17 – The challenge of organic soybean and corn production
0:49 – The system under research
1:36 – How the weed suppression works
2:05 – Results from the process
2:38 – Organic soybean yields
3:01 – Field Day Aug. 30
3:14 – Lead out
Transcript
Sevie Kenyon: Erin, welcome to our microphone. Tell us what you’re working on with your crop rotation program?
Erin Silva: Right now, in organic crop production, organic producers rely quite a bit on cultivation for their weed management because they can’t use herbicides. They have to go over the fields multiple times with various pieces of equipment such as tine weeders or rotary hoe or field cultivators. We’re looking at a system where organic producers have the option of no-till crop production, where they do not have to rely on mechanical cultivation for their weed management
Sevie Kenyon: Can you describe the system you’re looking at?
Erin Silva: The system that we’re looking at relies on the planting of a cover crop in the fall. Specifically, we’re looking at rye or vetch planted in September after a small grain crop comes off the field. It over winters and starts growing again in the spring and will reach maturity sometime in May. At the time that crop reaches maturity, either the rye or the vetch crop, we go through with what is called a roller crimper, which is essentially a big roller and rolls over the cover crop with chevron blades that crimp the cover crop and makes a big mat of mulch, killing the cover crop in the process.
Sevie Kenyon: What happens once that cover crop is knocked down?
Erin Silva: Once the cover crop is knocked down we come through and plant either soybean into the rye or field corn into the vetch and that can be drilled directly through that cover crop. Then that corn or soybean cash crop will grow through the mulch, but that blanket of mulch will prevent sunlight from reaching the soil’s surface and inhibit weed seeds from germinating and thus weeds from growing.
Sevie Kenyon: What kind of results have you seen?
Erin Silva: We’ve seen very promising results with the soybean–rye system. Out in our fields at the Arlington Agricultural Research Station, we’re actually seeing better weed management in our no-till system this year than in our standard organic treatments. So, essentially, in our rye-soybean system we’re seeing a weed free system, so the farmer only would have to go out once to get that cover crop crimped and then the cash crop planted. They wouldn’t have to go over the field again until harvest.
Sevie Kenyon: What kinds of yields do people get from these kinds of systems?
Erin Silva: With the soybean, we’re finding a pretty good yield. We’re working with several other states and they’re getting comparable results. Two of our states are finding a yield of about 30-35 bushels per acre. Generally, the kinds of producers we’ve been working with have found that to be a satisfactory yield for the benefits of the system.
Sevie Kenyon: If people are interested in this, is there something they can do to learn more?
Erin Silva: We’re having a field day at the Arlington Agricultural Research Station. We’ll be demonstrating this technique on August 30th and they can also feel free to contact me at the University of Wisconsin and I’d be happy to send them more information.
Sevie Kenyon: We’ve been visiting today with Erin Silva, Department of Agronomy, University of Wisconsin – Extension, in the College of Agricultural and Life Sciences, Madison, Wisconsin and I’m Sevie Kenyon.