. transvaalensis Burtt Davy cv. TifEagle] putting greens applied with foliar urea applications, providing evidence of lower environmental impact by foliar fertilization ( Stiegler et al., 2011 ). Nitrogen absorption with various N sources and factors affecting
Frank G. Bethea Jr., Dara Park, Andrew Mount, Nick Menchyk, and Haibo Liu
Cheng Bai, Charles C. Reilly, and Bruce W. Wood
role for Ni became evident with the discovery that urease (EC 3.5.1.5, urea amidohydrolase), a ubiquitous enzyme in plant organs, requires Ni for activation ( Dixon et al., 1975 ). Subsequent research by Brown et al. (1987a , 1987b) found that Ni met
Sameh Sassi-Aydi, Samir Aydi, and Chedly Abdelly
to the nutrient solution of only the symbiotic N-fixing plants. During the first 2 weeks, i.e., before nodule function, the nutrient solution was supplemented with 2 m m urea ( Ribet and Drevon, 1996 ). For urea-fed plants, 2 m m urea was added to
M. Lenny Wells
management, pecan tree response to N has been variable in multiple studies throughout the years ( Hunter and Lewis, 1942 ; Smith et al., 1985 ; Storey et al., 1986 ; Worley, 1974 , 1990 ). Ammonium nitrate and urea are the most common forms of dry N
Isaac T. Mertz, Nick E. Christians, and Adam W. Thoms
Antcliff, 1966 ; Mäkelä et al., 1996 ). Furthermore, compared with industry standard urea N, which must be converted to ammonium (NH 4 + ) by the enzyme urease before the N entering plant leaves and being assimilated into AA inside the plant ( Hull et al
Letizia Tozzini, Paolo Sabbatini, and G. Stanley Howell
sprayed with a urea solution (1% w/v) using a backpack sprayer to the whole vine canopy until runoff, whereas control vines (CN) were left unsprayed. Direct spraying of the clusters was avoided. Because number of leaves and, consequently, leaf area were
Carolyn F. Scagel, Richard P. Regan, and Guihong Bi
rate of N application to soil ( Bi et al., 2003 ; Cheng et al., 2001 ) and foliar sprays in the autumn with urea, are used to increase N reserves and improve growth during the following growing season ( Bi et al., 2005 ; Guak and Fuchigami, 2002
Qiang Liu and Yiwei Jiang
) water (W); 2) 10 m m urea (N10); 3) 20 m m urea (N20); 4) 15 µ m cytokinin (transzeatin riboside, ZR) (CK); 5) 10 m m urea + 15 µ m cytokinin (N10CK); and 6) 20 m m urea + 15 µ m cytokinin (N20CK). Pots were sprayed with 10 mL of solutions at each
Christian M. Baldwin, A. Douglas Brede, and Jami J. Mayer
15N–6.6P–12.5K fertilizer, an additional 15 lb/acre was applied using urea and AMS. Both dicamba and the N sources were applied alone or tank mixed with glyphosate at 0, 0.26, and 0.52 lb/acre. All treatments were applied on 3 Sept. 2010 and 2 Aug
Luther C. Carson and Monica Ozores-Hampton
ammonium (NH 4 + ) to nitrate (NO 3 − ) by bacteria or to slow the enzymatic transformation of urea to NH 4 + ( Trenkel, 1997 ). Controlled-release fertilizers, the last subgroup of EEFs, are urea, ammonium nitrate, potassium nitrate, or other soluble