Strip-tilling resulted in relatively greater yields across all seeding rates compared to conventional tillage under continuous corn in a one-site, non-replicated trial at Monsanto’s Learning Center near Monmouth, Ill., in 2011.

However, conventional tillage was the yield leader in the corn-soybean rotation at seeding rates of 35,000 and 42,000 per acre.

A greater yield response to tillage practices was observed in the corn-soybean rotation compared to continuous corn. This effect could be due to the boost in yield usually seen in corn-soybean rotations.

In general, strip-till had little effect in the first year of the tillage study, but fertilizer wasn’t placed in the strips in these trials.

This placement is one of the main advantages of the tillage system. Therefore, the results found in this study may not translate to other field situations.

Study Guidelines

Five trials were conducted in 2011 at the Monmouth Learning Center to evaluate the yield impact of multiple management practices on corn production under strip-till and conventional till.

The conventional-tillage system included chisel plowing in the fall and soil finishing in the spring. Weed management for all trials consisted of a pre-emergence application of Harness Xtra 5.6L at 2 quarts per acre and a post-emergence application of Roundup PowerMAX at 22 ounces per acre.

The Results

There were three separate trials that investigated the yield impact of planting date, seeding rate and foliar fungicide in strip-till and conventional tillage.

Only the late-planted corn showed a decrease in yield of 7.5 bushels per acre vs. the early and mid-planted corn. These results support previous studies by Monsanto and universities, which state that corn yield potential can decrease with delayed planting because of a shorter growing season, insect and disease pressure and moisture stress during pollination.

However, little difference between tillage systems was observed within any planting date.

Regardless of the rotational system, yield was similar for corn planted at 35,000 and 42,000 seeds per acre.

In general, there was a substantial decrease in yield of 15 bushels per acre at a seeding rate of 28,000 seeds per acre. The yield response to tillage practices varied depending on the rotational system.

Foliar fungicide and tillage practices had little effect on yield in either rotational system suggesting that foliar fungal disease pressure was low this year at this particular site.

Overall, tillage practices across all trials and rotation systems had very little effect on yield.

Similar demonstrations are planned in 2012 at the Monmouth Learning Center to include nutrient placement for strip-till.