Source: Mecosta Conservation District

The Mecosta Farm Bureau in collaboration with the Mecosta Conservation District hosted a tillage field day in Big Rapids, Mich., in 2014 with the goal of comparing the effects of different tillage types on the production of corn and soil structure. Below is an explanation of the experiment and comparison of the results.

The Experiment:

This past spring, an 8-acre test plot was put in to help compare the effects of differing tillage practices on corn yields. The five types of tillage systems were no-till, vertical-tillage with a Landoll implement, vertical-tillage with a Mandako implement, strip-till and a chisel/disc operation.

To limit the variability in the plot, the same corn variety and fertilizer applications were used across the plot. The seed corn, donated by Pioneer Seed Company, was P0255AMXT, with a 102 day maturity. Tillage and 200-pounds per acre of urea was broadcast on May 19, followed by a ½-inch rain the next morning which helped solubilize and incorporate the urea on the minimum tilled areas.

On May 22, the plot was planted with 250 pounds per acre of dry 19-9-28 fertilizer placed in a 2-by-2 inch band. The plot had three repetitions of the five tillage types. Harvest was completed on December 17, well after the first frost.

Results:

Jerry Mitchell prepares the strip-tilled plot.

Population data and seed spacing was taken from 3 sets of 17.4 feet from each repetition at the middle of the plot to avoid speed and down pressure complications. Plants that did not grow through the canopy because of weakness or slow start were not considered to reach maturation but are shown above on population densities of germination.

Lengths and widths were calculated for each plot for acre calculations. Plots were harvested and weighed using a weigh wagon and averaged between repetitions. Moisture readings and test weights were taken using a sample probe at approximately 4 feet into each load, representing each plot.

Samples were analyzed using a hand testing unit borrowed from Montcalm Michigan State Extension and repeated 3 times. The average bushel per acre was then derived from the pounds per acre harvested divided by the measured test weights. The first repetition with the Mandako implement was removed from the data due to the headland effect on plant vigor. 

Also, it should be noted that the chisel/disc harvest has an error of 2-4 bushels per acre do to the rock trap door being open when harvest first started.

Conclusion:

Since there was a limit to the design of this plot and its execution, limited conclusions can be drawn. Results like these can also vary quite a bit under different climatic, soils and mechanical conditions. It is interesting to see the similarity in test weights with one exception in strip tillage. Moisture levels were even more similar.

This brings us to the most interesting part, the yields. Looking back to the planting statistics attached we can derive at least one factor that can play a role in the reduced pounds per acre with the chisel/disc operation. There are fewer plants per acre and greater average distance between the plants; this is possibly due to a high downward pressure suited to minimum tillage verses the softer chiseled ground.

This indicates as stated at the event that the planter settings are crucial to getting a good stand of corn. There are many influences to what makes a good stand of corn, how you put that seed in the ground is one of them. The way you prepare your soil, fertilize it and plant into it all have to come together as a complete system. With the right planter that system can still produce good crop yield on untilled soil.