Strip tillage is one of the conservation tillage options available for managing corn residue prior to planting soybeans. Interest in strip tillage is increasing because it offers the following benefits:
- Reduced soil erosion compared to conventional tillage (when slopes are less than 5 percent).
- Increased water infiltration compared to full-width tillage.
- Faster and more uniform germination and emergence than other conservation tillage options due to increased soil warming in the spring.
- Less soil moisture loss due to evaporation than chisel plowing followed by soil finishing.
- Equal or better yields than no-till, vertical tillage and more intensive full-width tillage systems based on multiple-year data from Minnesota and North Dakota.
- Reduced tillage costs by $6 per acre compared to a fall chisel operation followed by a spring soil finishing operation (2012 University of Minnesota figures).
This article summarizes the results from three Michigan on-farm research trials evaluating strip tillage effects on soybean yields. The strip tillage implement used in all three trials was a Dawn Pluribus set to operate on 30-inch centers. No fertilizer was applied during the strip tillage operations and all treatments were planted with a 30-inch no-till planter. Two of the trials were conducted near Niles, Mich., on coarse-textured soils. One of the trials was conducted in 2011 and the other in 2012. Each of these trials consisted of three treatments: fall strip tillage, spring strip tillage and an untilled control.
In 2011, the two strip tillage treatments produced significantly higher yields than the untilled control, but were not significantly different from each other (Table 1). In 2012, the spring strip tillage treatment produced a significantly higher yield than the fall treatment which was significantly higher than the yield for the untilled control. This was also true when both trials were combined and analyzed. The spring strip tillage treatment was also the most profitable, producing $16 more per acre than fall strip tillage and $33 more per acre than the untilled control.
The third strip tillage trial was conducted near Melvin, Mich., in 2012 and consisted of only two treatments: spring strip tillage and an untilled control. At this site, there was not a statistically significant difference between the yields produced by the strip tillage and the untilled control. The soil texture was much finer at this location. This trial was also the first time the producer operated the strip tillage tool. Like other tillage implements, proper adjustment and operation of strip tillage tools are essential to maximizing performance.
The results obtained from these three trials are consistent with results from trials conducted in Minnesota and North Dakota where soybeans grown in a strip tillage system were shown to yield equal to or better than those grown in no-till or conventional tillage systems. In these trials, the strip tillage operations were performed in the fall. The researchers recommend fall strip tillage over spring strip tillage due to improved soil warming and seed-to-soil contact. This may be more important on fine-textured soils than it is on the coarse-textured soils near Niles, Mich.
Based on the results from these trials, strip tillage looks promising for soybean production in 30-inch rows in Michigan. However, strip tillage should be restricted to fields having slopes less than 5 percent to reduce the potential for water erosion occurring in the rows.