/AnMtgsAbsts2009.54224 Long-Term Continuous Corn and Nitrogen Fertilizer Effects On Productivity and Soil Properties.

Wednesday, November 4, 2009: 2:45 PM
Convention Center, Room 319, Third Floor
Matthew D. Ruark, Larry Bundy, Todd Andraski and Arthur Peterson, Soil Science, Univ. of Wisconsin, Madison, Madison, WI
There are uncertainties about the sustainability of long-term monoculture and nitrogen (N) fertilizer use in corn production.  Long-term research (50 years) at the Arlington Agricultural Research Station has examined the effects of continuous corn and N fertilizer use on corn yield, N use efficiency, and soil characteristics.  Corn was harvested for grain with residues returned annually since 1958 on a Plano silt loam soil (fine-silty, mixed mesic, Typic Argiudolls).  The experimental design includes three N fertilizer rates (currently, 0, 140 and 280 kg N ha-1) and two lime treatments (imposed in 1985) with four replications.  Soil pH and organic matter content were measured periodically during the experiment.  Average corn yields in N fertilized treatments increased dramatically (100%) over time with some of the highest yields occurring in the most recent years.  Nitrogen use efficiency (grain N/fertilizer N) also increased over time, thus higher yields in recent years have not required greater N fertilizer use.  Soil organic matter content was at least maintained and, in some cases, increased with long-term N additions, thereby enhancing the soil N supply capability.  Soil pH decreased with long-term N use without lime addition, and since 1987, lime treatments increased yields in 13 of 21 years.  Increasing productivity and N use efficiency along with no reduction in soil organic matter suggest that long-term continuous corn and N fertilizer use are sustainable practices in southern Wisconsin.