John Sawyer

Articles by this author

Farmers are reminded to wait until soil temperatures remain below 50 degrees Fahrenheit before applying anhydrous ammonia (NH3) fertilizer this fall. Harvest is progressing rapidly in many parts of the state and officials with the Iowa Department of Agriculture and Land Stewardship and Iowa State University Extension and Outreach said that waiting can help reduce nitrogen loss and better protects the environment.

By: John Sawyer and Elwynn Taylor and Dustin Vande Hoef

The regional Corn Nitrogen Rate Calculator website, which has been helping farmers determine profitable nitrogen rates since 2005, now has a new URL, a revised nitrogen response trial database, and is more user-friendly for mobile devices.

By: John Sawyer

Farmers are reminded to wait until soil temperatures remain below 50 degrees Fahrenheit before applying anhydrous ammonia (NH3) fertilizer this fall.

By: John Sawyer and Dustin Vande Hoef

Iowa State University Extension and Outreach will offer a two-day short course Feb. 8-9 focusing on principles of soils, soil fertility and nutrient management to help crop production professionals make more informed decisions.

By: John Sawyer and Brent Pringnitz

To explain how to take good soil samples, Iowa State University Extension and Outreach has released a new publication, "Take a Good Soil Sample to Help Make Good Fertilization Decisions."

By: Antonio Mallarino and John Sawyer

The practice of conducting tissue testing for phosphorus and potassium in corn and soybean is a relatively new tool in Iowa crop production. While soil testing has been widely used for decades, proper tissue testing recommendations are still emerging.

By: Antonio Mallarino and John Sawyer

A newly revised publication, “Use of the End-of-Season Corn Stalk Nitrate Test in Iowa Corn Production” (CROP 3154) is available through the ISU Extension Store. The publication is written by John Sawyer and Antonio Mallarino, professors and extension specialists in agronomy at Iowa State University.

By: John Sawyer and Antonio Mallarino

ISU Extension and Outreach will be offering a two-day short course focusing on principles of soils, soil fertility and nutrient management to help crop production professionals make sound decisions.

By: John Sawyer and Brent Pringnitz