Project title: Improving Nutrient Use Efficiency for Corn

Principal investigators: Richard Ferguson, Gary Hergert, Charles Shapiro, Tim Shaver, Dan Walters, Charles Wortmann

Duration: On-going

Funding: Nebraska State Legislature

Contact:

Charles Wortmann, Department of Agronomy and Horticulture, UNL, 58C Filley Hall, Lincoln, NE, 68583-0951, (402) 472-2909 cwortmann2@unl.edu

Charles Shapiro, Northeast Research and Extension Center, Haskell Agricultural Laboratory, UNL, 57905 866 Road, Concord, NE 68728-2828, (402) 584-2803, cshapiro1@unl.edu

Project description:

1. Responses to nitrogen, phosphorus and potassium were evaluated in 34 high yield trials conducted between 2002 to 2004. Response to S was evaluated in fewer trials.
2. In another study, the effect of soil test P levels on corn yield is being evaluated. The targeted levels of Bray-1 soil phosphorus are 15, 30 and 45 ppm. In addition, a no phosphorus control and an application of phosphorus at removal rates are included.

Key results:

Recommendations for nitrogen and phosphorus were revised.

1. Bray-1 P critical levels of 20 ppm for corn following corn and 15 ppm for corn following soybean were determined. Recommendations for potassium and sulfur were validated.
2. In the study with targeted Bray #1 P levels, yield has been slightly more with P applied at the removal rate (Bray-1 P = 24 ppm) compared with the Bray #1 P target of 15. Applying P for target levels of 30 and 45 ppm Bray-1 has been the least economical options.

Publications:

Wortmann, C.S., A.R. Dobermann, R.B. Ferguson, G.W. Hergert, C.A. Shapiro, D.D. Tarkalson, D. Walters. 2008. High yield corn response to applied phosphorus, potassium, and sulfur in Nebraska. Agron. J. 101 546-555.

Shapiro, C.A. , R.B. Ferguson, G.W. Hergert, and C.S. Wortmann. 2009. Fertilizer suggestions for corn. University of Nebraska-Lincoln Extension EC 117.

Dobermann, A., R. Ferguson, G. Hergert, C. Shapiro, D. Tarkalson, D. Walters, C. Wortmann. 2006. Should we abandon soil testing and yield goals in estimating nitrogen rates for corn? Proc. North Central Region Industry-Extension Soil Fertility Conference, Des Moines, Ia.

Dobermann, A., R. Ferguson, G. Hergert, C. Shapiro, D. Tarkalson, D. Walters and C. Wortmann. 2006. Nitrogen response in high yielding corn systems of Nebraska. Great Plains Soil Fertility Conference, Denver, Colo., p. 50-59.