Farm Progress is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Serving: IN

Purdue Releases Nitrogen Rates Based on 8 Years of Trials

Purdue Releases Nitrogen Rates Based on 8 Years of Trials
There are different recommended rates for different parts of the state.

There's a trend toward needing more nitrogen applied per acre per year in some parts of the state – and less nitrogen in other parts – to reach optimum agronomic yield. That became apparent fairly early in Purdue University's study of N rates on regular farms and on Purdue research farms. The study began in 2006.

The trend continued, and is evident in the 8-year data summary Bob Nielsen, Jim Camberato and Brad Joern issued after including their results from 2013. Remember that these rates are what it takes to reach maximum agronomic yield. There is a difference between maximum agronomic yield and maximum economic yield. The latter varies with the price of N and price of corn.

Various methods: This corn was sidedressed N injected on every other row. Various methods and timing of applications are included in the 8-year Purdue N study.

Based on 37 trials in west-central, southwest and south-central Indiana on medium and fine-textured soils, the trio concluded that the optimum rate for maximum yield is a total of 182 pounds of N per acre. That includes N applied from all commercial sources in a corn and soybean rotation.

Based on 33 trials in northwest, north-central and southeast Indiana, on the same texture of soils as before, the optimum rate rose to 194 pounds of N per acre. Remember, this is based on an 8-year average.

In northeast, east-central and central Indiana, the number to produce top agronomic yield is higher. The eight-year study suggests a rate of 217 pounds of N per acre per year in a corn and soybean rotation. This is again on medium and fine-textured soils in 54 trials.

These results are from field-scale trials, Nielsen notes. Several farmers around the state cooperated, so many of the studies were carried out on actual farms.  Remember that these rates are strictly based on maximum yield. They do not account for the economics of N costs and corn prices.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.