Soil Fertility

Nutrient Topics

Questions? Contact John Sawyer

Professor
Extension Soil Fertility Specialist
Phone: (515) 294-7078
Email: jsawyer@iastate.edu

Antonio Mallarino

Professor, Soil Fertility
Phone: (515) 294-6200
Fax: (515) 294-2458
Email: apmallar@iastate.edu

Soil Fertility Home Page

Welcome to the Iowa State University Agronomy Extension Soil Fertility Home Page. Nutrient topics are listed on the left side. Simply click on a topic of interest and you can find information about that topic, including Extension publications, newsletter articles, conference proceedings and reports, presentations, and links to other related sites. Links also provide access to soil fertility decision aid tools, a photo gallery, and the ISU Soil and Plant Analysis Laboratory.

Current Topic

CORN NITROGEN RATE CALCULATOR UPDATE

John E. Sawyer, Professor, Department of Agronomy, Iowa State University
July 21, 2014

The Iowa N response database in the Corn Nitrogen Rate Calculator was recently updated, with response trials added from 2013 research. There are now 246 trials for corn following soybean and 133 trials for corn following corn. Being able to easily update the database with recent data is one of the many advantages to this dynamic database approach for corn N rate guidelines. Having new response trial data allows rapid updating with changing hybrid genetics, rotations and climatic conditions. Read on.

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