With an average of 30,750 plants per acre as of November, Iowa corn producers planted the highest density per acre, besting Illinois by 350 plants. The National Agriculture Statistics Service collected objective yield data in 10 corn-producing states during 2011. Randomly selected plots were visited monthly from August through harvest to obtain counts and measurements.Since 2007, a steady increase in the number of plants per acre has occurred. Eight of the ten states saw the number of plants per acre jump from the end of 2010, as well. The plants per acre as of November in the 10 states were:
- Illinois - 30,400
- Indiana - 29,150
- Iowa - 30,750
- Kansas - 21,500
- Minnesota - 30,250
- Missouri - 25, 800
- Nebraska - 25,450 (28,250 for irrigated and 21,200 for non-irrigated)
- Ohio - 29,350
- South Dakota - 25,500
- Wisconsin - 28,950
The number of ears per acre since 2007 has also risen in seven of the ten states. Ohio has seen the greatest jump going from 25,950 ears per acres in 2007 to 29,150 ears per acre in November, an additional 3,200 ears per acre. Numbers in the 10 states are:
- Illinois - 29,550
- Indiana - 27,750
- Iowa - 30,050
- Kansas - 20,650
- Minnesota - 29,350
- Missouri - 24,550
- Nebraska - 24,350 (26,800 for irrigated and 20,650 for nonirrigated)
- Ohio - 29,150
- South Dakota - 25,250
- Wisconsin - 28,650
In 2011, six of the states had over 40 percent of their corn planted at over 30,000 plants per acre. The exceptions were Kansas, with plant densities less than 20,000 plants per acre on 33 percent of operations; Missouri, 24 percent of plots between 22,501 and 25,000; South Dakota, approximately 18 percent in the four categories between 22, 501 and more than 30,000; and Nebraska with 34 percent of plots between 27,501 and 30,000.
Overwhelming, the majority of plots were planted with a 30-inch row width. Minnesota averaged 28.8-inch rows and Wisconsin has gradually reduced its average row width from 31.1 to 29.6 over the last four years.
