InfoAg 2017 Presentation
Advances in VR Nutrients

Regency C
Wed, Jul 26, 2017
8:00 AM to 10:00 AM

Advances in VR Nutrients (Repeat)

Regency C
Wed, Jul 26, 2017
1:20 PM to 3:20 PM


Much of the phosphorus (P) fertilizer applied across the US is applied using a variable rate (VR) strategy. Often we interpolate soil P data and use standard soil test interpretations to develop VR prescriptions. We need to critically examine this approach. Can traditional soil test critical values (the soil P concentration below which we expect P fertilizer response) and fertilizer recommendation systems be used under a VR management strategy? How precise are interpolated soil test maps? These questions and others will be examined as we discuss ongoing research into VR-P.

Joshua McGrath
Extension Associate Professor
University of Kentucky
Plant Science Building
1405 Veterans Drive
Lexington, KY 40546-0312
Extension Specialist - Agricultural Soil Management. Applied research and extension in agronomic soil fertility and nutrient management to maximize profitability, efficiency, and protect natural resources. Specializing in site-specific nutrient management, manure management, and water quality protection.

Dr. Josh McGrath joined the University of Kentucky as an Associate Professor and Soil Management Specialist in July of 2014 after eight years on faculty at University of Maryland. Dr. McGrath