Research HighlightsStrip-Tilling to Manage Early Season Wisconsin Conditions
By Barb Baylor Anderson
Soybean farmers have steadily improved soybean yields over the last few years with the innovative management tools researchers have given them. But in Wisconsin and other parts of the Upper Midwest, farmers are annually challenged with yield-suppressing conditions that include cold, dense soils, difficult early season planting conditions and highly erodible soils.
To resolve these issues, many farmers have found tillage is an effective soil management technique. However, the combination of tillage and erodible landscapes can increase soil loss.
“Current recommendations in Wisconsin for soybeans produced in a corn/soybean rotation are to use no-till, 15-inch row spacings,” says Shawn Conley, University of Wisconsin soybean specialist and principal investigator of strip-till research funded by the Wisconsin Soybean Marketing Board. “Due to a perceived yield plateau with no-till soybeans, however, farmers are exploring strip-till to improve early season planting while maintaining soil structure and health.”
By combining strip-till with commonly used management practices (row spacing, fertilizer placement and in-furrow fungicide use), Conley set out to evaluate strip-till’s effects on soybean plant population, canopy coverage and yield, as well as impact on soil temperature and penetration resistance. The goal was to determine best management advice for strip-till use.
“As farmers increase their productivity in soybeans, research plays an important role. Soybean research keeps the American farmer on the cutting edge of production in our global market,” says Matt Wagenson, soybean farmer from Bear Creek, Wisc., and secretary/treasurer for the North Central Soybean Research Program (NCSRP). “Every season brings new challenges to soybean producers and soy research is there to guide producers through those challenges.”
Management practices for the study consisted of 12 combinations of spring strip-till or no-till, deep-banded or broadcast fertilizer, 15-inch or 30-inch row spacings, and in-furrow fungicide use versus a non-treated control. Conley’s team made a number of observations in both small plot trials and on-farm trials over a three-year period:
- Soybean yield was similar between strip-till 30-inch rows and no-till 15-inch rows.
- Plant population was 9,100 plants per acre and eight percent greater in 30-inch rows than in 15-inch rows. Plants in 30-inch rows likely benefited more from intra-plant assistance during emergence due to their reduced intra-row spacing.
- The small plot yield response to strip-till was affected by other management practices.
- Canopy coverage results were varied. No soil temperature differences were observed.
“Based on our results in Wisconsin, farmers utilizing 15-inch row spacings should consider using no-till and surface-applied fertilizer, while farmers using 30-inch row spacings should consider strip-till and banded fertilizer,” says Conley. “In-furrow fungicide yield response was management specific. More research is needed to make a clear recommendation for its use with an average planting date in farmers’ fields. Optimum planting date resulted in the highest yield.”