Maximizing yield with continuous corn (CC) fields is more difficult than with corn-soybean rotations (CS). This is true even with intensively managed CC systems, as yield-limiting factors are not fully understood. A recent six-year study conducted by Laura Flint Gentry, Ph.D., University of Illinois, reported that CC yielded 25 fewer bu/acre than CS, and identified three factors — soil nitrogen (N) supply, CC history and weather — as responsible for more than 99 percent of the CC yield penalty.

  • To explain the difference between CS and CC yields, N supply was, by far, the most important factor. The CC yield penalty decreased as intrinsic soil N supply capacity increased.
  • The number of CC years was the second most important component of the yield penalty. The difference between CS and CC yields increased with years in CC.
  • The third driver was weather. The CC yield penalty increased as weather conditions limited N availability to CC; this occurred to a much greater degree than to CS.
  • The study’s results indicate that positioning CC on highly productive soils and effectively managing corn residues are two of the most important practices for consistently achieving high CC yields.

Growers farming CC acres can employ several best-management practices to maximize yields, including hybrid selection, tillage, soil fertility, and weed and insect control. Visit for a complete review of best-management practices for corn-after-corn production.

A paper summarizing the U of I study was written by Andy Hegenstaller, agronomy research manager, DuPont Pioneer. Yield Limiting Factors in Continuous Corn Production.

For more information, view the full Crop Insights online or contact your Pioneer sales professional.