On-farm comparison: Conservation tillage systems

Here, you’ll find guidance on selecting a conservation tillage system for corn in a corn-soybean rotation. We share the results of on-farm yield trials conducted across southern Minnesota, as well as management tips for conservation tillage.

Selecting a tillage system requires you to consider many factors, including soil and water conservation, economic return, labor availability and management capability, all of which are specific to the individual farming operation.

About conservation tillage

Conservation tillage systems that leave at least 30 percent residue cover on the soil surface after planting. Reduced-tillage systems have benefits other than soil conservation, such as:

  • Increased water infiltration.

  • Increased or sustained organic matter content.

  • Increased water-holding capacity.

  • Continued long-term soil productivity.

  • Less capital investment in equipment and fewer field passes. This reduces the amount of labor and fuel used.

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On-farm research: Tillage systems

Research on Minnesota farms shows that conservation tillage can greatly reduce soil erosion, with minimal effect on crop yields and often at lower production costs than conventional tillage. With appropriate adjustments to crop management, conservation tillage offers a low-risk way of substantially reducing sediment and phosphorus losses from cropland to streams, rivers and lakes.

Tillage research for corn following soybean conducted on Minnesota farmers' fields in 2004 and 2005 has shown:

  • Tillage treatments had a greater impact on crop production in the cooler-than-normal growing season (2004) than in the warmer-than-normal growing season (2005).

  • Grain moisture was significantly higher with reduced tillage systems in 2004, but not in 2005 (data not shown).

  • Residue coverage after planting corn varied considerably among sites and averaged 60, 47, 29 and 21 percent for no-till, strip-till, one-pass and chisel-plow-plus, respectively.

  • Significant differences in final plant populations among tillage treatments were rare. When they occurred, they were generally small.

  • Averaged over years, corn yields were greatest for chisel-plow-plus and strip-till, intermediate for one-pass and least for no-till.

These data showed reduced tillage systems like strip-till can produce yields similar to conventional tillage systems like chisel plow, while maintaining adequate residue cover and reducing the risk of soil erosion.

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Management tips for reduced-till systems

Tillage systems that leave more than 30 percent residue after planting corn work for many producers. However, you may need to adjust your management strategy throughout the whole cropping system, in addition to changing tillage implements.

Successful producers have made the following observations and suggestions:

  • Well-drained soil, either natural or artificial, is beneficial for enhanced yield performance in a reduced-tillage system.

  • Use chaff spreaders or choppers to evenly distribute chaff leaving the combine. This helps avoid planting or tilling through piles of residue.

  • Residue managers on the planter enhance early growth and promote uniform seed germination (Figure 10).

  • Use a heavy-duty, reduced tillage planter that’s capable of proper depth control and firm seed-to-soil contact for good germination.

  • Band-apply a starter fertilizer next to the corn row is good insurance against restricted root growth in cold, wet, fine-textured soils (Figure 11).

  • Band or inject nitrogen fertilizer, if possible, rather than broadcasting it.

Residue managers
Figure 10: Residue managers on the planter to clear the row.
strip-till pass
Figure 11: Applying banded P and K fertilizer with the strip-till pass.

Strip-tillage management tips

  • Match the strip-till toolbar’s width to that of the planter to ensure row alignment. Corn planted outside the strip is essentially no-till and may suffer in yield.

    Berms
    Figure 12: Berms built in the fall should be at least 1 inch high by planting.
  • Auto-guidance systems can help ensure alignment of the planter on the strips.

  • In strip-till corn after corn, leave corn stubble standing for maximum air movement and less residue-matting, and build the strips between the previous crop rows.

  • Build strips in the fall rather than in the spring for the greatest soil warm-up and seed-to-soil contact.

  • In the cooler, fine-textured soils, strip tillage equipment should clear the berm to less than 10 percent residue for faster soil warm-up in the spring. 

  • Build a high enough berm in the fall so that it’s at least 1 inch high by planting (Figure 12). If the tilled area is level or there’s a trough in the spring, the berm wasn’t high enough for rapid drying.

  • Band P and K fertilizer with the fall strip tillage pass to improve the economic advantages of strip-till. This reduces trips across the field and allows the lower rates recommended for banded versus broadcast application.

Appendix

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Jodi DeJong-Hughes, Extension educator and Jeffrey Vetsch, researcher, Southern Research and Outreach Center

Acknowledgements

The project couldn’t have been accomplished without the site management carried out by the producers and research coordinators listed in Appendix Tables 1 and 2. We wish to thank the staff of Department of Agriculture Natural Resources Conservation Service and Soil and Water Conservation Districts for their contributions to site management in the following counties: Cottonwood, Grant, Pope, Rice, Sibley, Stearns and Wabasha.

This project was funded by an Environmental Protection Agency 319 grant awarded by the Minnesota Pollution Control Agency and managed by the University of Minnesota Water Resources Center, Les Everett project manager. In addition, the Monsanto Corporation provided funding and management of seven on-farm trial sites.

Content was reviewed by Gyles Randall, edited by Tracy Wilson and Les Everett and designed by Amy Baker.

Reviewed in 2018

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