Agronomic Management of Soybean and Corn by Indiana Producers.

A questionnaire survey was designed to document the key agronomic practices and concerns for Indiana’s two major crops – soybean and corn.  The mail-out survey was sent to 5,000 soybean and corn producers in Indiana prior to the 2010 growing season.  The response rate was 24%.  Two-thirds of the respondents farmed for over 30 years followed by 17%, 10%, and 5% farmed for 21-30, 11-20, and 6-10 years, respectively.  The farm size averaged 735 ac (294 ha) with nearly an even split between soybean and corn.  Seventy-two percent of the respondents were in a corn-soybean rotation.  Relative changes in the planting dates of soybean and corn of today compared to 10 years ago were similar among respondents.  Approximately 33% and 20% were planting one and two wk earlier, respectively, while 40% had not changed.  Soybean planting of 126,000-175,000 and 176,000-250,000 seeds ac^-1 (315,000-437,500 and 440,000-625,000 seeds ha^-1) represented 56% and 29% of today’s rates, respectively, versus 33% and 54% ten years ago, respectively.  Sixty-eight percent of the respondents planted corn at 25,000-29,000 seeds ac^-1 (62,500-72,500 seeds ha^-1) ten years ago and presently, 68% of the respondents planted corn at 30,000-34,000 seeds ac^-1 (75,000-85,000 seeds ha^-1).  No-tillage system represented 66% of soybean following corn and 33% of corn following soybean.  Twenty-three percent of the respondents applied foliar fungicides in the past two growing seasons in both soybean and corn.  Foliar insecticides were applied by 25% and 16% of the respondents to soybean and corn, respectively.  The most challenging agronomic factors were unpredictable weather extremes (~70%) followed by variety/hybrid performance (~35%), poorly drained soils (~33%), and weeds (~30%).  Information gleaned from the survey results will help direct future efforts in agronomic Extension and research at Purdue University that directly meet the needs of Indiana soybean and corn growers.