A Sensor Based Nitrogen Rate Calculator for Cotton

Sensor use in cotton production is no longer a new topic.  Sensors have been evaluated use in determining plant growth regulator and defoliant applications.  One of the more complicated areas of interest is the use of sensors to determine site specific nitrogen (N) fertilization rates. Scientist at Oklahoma State University have been working with the GreenSeeker ™ hand held sensor in the N management area. After the 2007 crop year a yield prediction model (YP0) was developed and nitrogen fertilization optimization algorithm (NFOA) proposed.   The NFOA utilized the reference strip, N-rich strip, and mid-season yield prediction approach to develop a site specific N rate recommendation.  During the 2008 crop year the YP0 was evaluated and built upon.  The NFOA was also implemented into a Sensor Based Nitrogen Rate Calculator (SBNRC) and this calculator was used to prescribe sidedress N rates.  The yields and lint quality of the SBNRC recommended rates treatments were compared to the convention N management treatments.