Blends and Timing of Environmentally Smart Nitrogen and Urea: Effects on Cotton Yield and Quality

Wednesday, January 6, 2016
Mardi Gras Ballroom Salons E, F, G & H (New Orleans Marriott)
Thursday, January 7, 2016
Mardi Gras Ballroom Salons E, F, G & H (New Orleans Marriott)
Michael J. Mulvaney , University of Florida
Heather Enloe , University of Florida
Environmentally Smart Nitrogen (ESN) is a commonly available controlled-release N source for crop production and may offer benefits for cotton yield and quality compared to urea.  Pure formulations and blends of ESN and urea were applied either pre-plant or split applied at two locations in 2015. Blend treatments were 100% urea, 50:50 urea:ESN, 25:75 urea:ESN, and 100% ESN, plus a 0 N check.  Application timing treatments were 100% at planting or 25% at planting/75% at first bloom. Treatments were arranged as a randomized complete block with four replications at Jay, FL and Citra, FL. ESN release rates for both applications were determined using litterbag methodology at both locations. ESN release rates will be discussed in conjunction with N source and timing effects on cotton yield and quality.