299-10 Is Sulfur Limiting Corn Yields In Illinois?.



Wednesday, October 19, 2011
Henry Gonzalez Convention Center, Hall C, Street Level

Fabian G. Fernandez1, Kristin D. Greer1 and Stephen A. Ebelhar2, (1)1102 South Goodwin Avenue, University of Illinois, Urbana, IL
(2)University of Illinois, Simpson, IL
The last statewide survey to determine corn response to sulfur (S) in Illinois, USA was conducted over three decades ago where only 5 out of 82 sites showed a mean 0.7 Mg ha-1 corn grain yield increase with S application. Since that earlier study a combination of increasing S uptake by higher-yielding crops and a reduction of S inputs from the atmosphere and in the inputs used in farming today might be causing insufficient S supply for corn. Our objective was to quantify the likelihood of corn response to S in relation to soil characteristics and location within Illinois. Small plots (3 x 9 m) received ammonium sulfate (NH4)2SO4 (21-0-0-24); two forms of MicroEssentialsTM S (ME S)— ME S15 (13-33-0-15) and ME S10 (12-40-0-10); calcium sulfate (gypsum) CaSO4·2 H2O [0-0-0-22(Ca)-17(S)]; and elemental S (0-0-0-90). Sources were applied at a rate of 26 kg S ha-1, except for ME S15 that was applied at 0, 13, 26, 39, 52 kg S ha-1 in a randomized complete block design with 4 replications at six locations in Illinois in 2009 and 2010. In addition, strip trials with 0 and 34 kg S ha-1 replicated four to seven times were established in 18 on-farm fields throughout the state. Plant-tissue samples were analyzed for S and grain yield data were collected. No response to S source was observed in the small-plot sites. While ear-leaf S content was above the sufficiency level (1.5 g kg‑1), S content increased with each successive S rate to 39 kg S ha-1. Grain yield increased in three out of 12 site-years, on a silty-loam soil in east-central Illinois and on a fine sandy-loam soil in northern Illinois, with an application of 26 kg S ha-1 that produced a mean yield increase of 1.6 Mg ha-1 relative to the unfertilized treatment and maximized grain yield at 13.1 Mg ha-1. Two out of 18 on-farm sites showed an increase in yield with S application. A 34 kg S ha-1 application on a sandy-loam soil in central Illinois produced a 3.2 Mg ha-1 increase above the 10.5 Mg ha-1 yield produced in the unfertilized strip, and a silt-loam soil in east-central Illinois produced a 1.3 Mg ha-1 increase over the unfertilized strip. These data indicate that the frequency of S deficiency and magnitude of yield response to S application seem to have increased since the earlier study.
See more from this Division: Canadian Society of Soil Science
See more from this Session: Crop Responses, New Management Strategies, and Improved Methods for Assessing Sulfur Needs I