Understanding the Nitrogen Cycle for management of field, vegetable, and fruit crops in Wisconsin.
Nutrient Application Guidelines for Field, Vegetable, and Fruit Crops in Wisconsin
http://learningstore.uwex.edu/Nutrient-Application-Guidelines-for-Field-Vegetable-and-Fruit-Crops-in-Wisconsin-P185.aspx
PSNT video --
https://www.youtube.com/watch?v=oSlpTl0oKog
Carrie Laboski, University of Wisconsin-Madison professor and UW-Extension soil scientist
http://www.soils.wisc.edu/extension/dir/laboski.php