Project title: Effect of Tillage, Nitrogen and Rotation on Corn and Soybean Yield

Principal investigators: Charles Shapiro, Dan Walters

Duration: 1986 to present

Contact:

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

Dan Walters Department of Agronomy and Horticulture, UNL, 261 Plant Science, Lincoln , NE 68583-0915, (402) 472-1506, dwalters@unl.edu

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

Project description:

1. Spring plow, disk and no-till are compared in continuous corn and a corn-soybean rotation at five nitrogen rates ( 0, 40, 80, 120 and 160 kg/ha N). This study has been conducted since 1986 with changing genetics and herbicide use. It is being conducted on a Kennebec silt loam, with about 4.5% organic matter. The study is rainfed and annual precipitation has ranged from 15 (1989) to 41 (1993) in/year over the length of the study.
2. The effects of one-time tillage of no-till land on grain yield, P distribution, soil organic carbon (SOC), water stable aggregates (WSA), and soil microbial communities over a five year period were determined.

Key results:

1. Corn yields have ranged from 35 to 180 bu/acre depending on treatment. Average corn yield was 25 bu/acre more following soybean compared with continuous corn. Tillage treatments differed by an average of 3.5 bu/acre over 22 years but the yield advantage of no-till has increased over time to 12 bu more than plowing and 6 bu more than disking. Nitrogen application has increased yields. The average yield with no N applied is 118 bu/acre for corn after soybeans and 83 bu/acre for continuous corn.
2. The effect of one-time tillage of no-till has been generally neutral without much effect on yield or other properties measured.

Publications:

Yamoah, C.F., D.T. Walters, C. A. Shapiro , C.A. Francis, and M.J. Hayes. 2000. Standarized precipitation index and nitrogen rate effects on yields and risk distribution of maize. Agriculture Ecosystems and Environment. 80:113-120.

Wortmann, C.S., J.A. Quincke, R.A. Drijber, M. Mamo, T. Franti. 2007. Soil microbial change and recovery after one-time tillage of continuous no-till. Agron. J. 100:1681-1686.  

Quincke, J.A., C.S. Wortmann, M. Mamo, T.G. Franti, R.A. Drijber, and J.P. Garcia. 2007. One-time tillage of no-till systems: soil physical properties, phosphorus runoff, and crop yield. Agron. J. 99:1104-1110.

Quincke, J.A., C.S. Wortmann, M. Mamo, T. Franti, and R.A. Drijber. 2007. Occasional tillage of no-till systems: CO2 flux and changes in total and labile soil organic carbon. Agron. J. 99:1158-1168.

Garcia, J.P., C.S. Wortmann, M. Mamo, R. A. Drijber, J.A. Quincke, and D. Tarkalson.2007. One-time tillage of no-till: effects on nutrients, mycorrhizae, and phosphorus uptake. Agron. J. 99:1093-1103.