TY - JOUR
T1 - Value of copper, zinc, and oxidized charcoal for increasing forage efficiency of urea N uptake
AU - Guimarães, Gelton G.F.
AU - Mulvaney, Richard L.
AU - Cantarutti, Reinaldo B.
AU - Teixeira, Breno C.
AU - Vergütz, Leonardus
N1 - Publisher Copyright:
© 2016 Elsevier B.V..
PY - 2016/5/15
Y1 - 2016/5/15
N2 - Volatilization losses reduce the efficiency of surface-applied urea for crop N uptake, and can be controlled using urease inhibitors to retard hydrolysis or by the presence of other amendments that enhance retention of NH4+ formed by urea hydrolysis. A greenhouse study was conducted to evaluate the effectiveness of oxidized charcoal (OCh; 150 g kg-1 fertilizer) applied with or without Cu and/or Zn (~0.5-2 g kg-1 fertilizer), and of Cu and/or Zn applied without OCh, for increasing uptake of urea 15N by a common tropical pasture grass, capim-Mombaça (Panicum maximum Jacq. Cv. Mombaça), grown on a coarse-textured Oxisol. Cuttings were collected 5, 14, 28, 42, and 56 days after surface placement of amended or unamended urea pellets to estimate dry matter production, total N uptake, and 15N recovery. Soil sampling was carried out in conjunction with the first and fourth cuts to evaluate exchangeable NH4+ and NO3- concentrations. At the concentrations studied, OCh was more effective than Cu and/or Zn for prolonging NH4+-N availability in urea-treated soil; however, OCh alone or in combination with Zn and Cu had no effect on biomass production or N recovery and can safely be eliminated as a useful option for pasture improvement. The most promising amendment was Zn, which significantly increased total N uptake and the efficiency of urea N fertilization. The use of Zn in conjunction with urea has practical potential to improve forage production on tropical soils.
AB - Volatilization losses reduce the efficiency of surface-applied urea for crop N uptake, and can be controlled using urease inhibitors to retard hydrolysis or by the presence of other amendments that enhance retention of NH4+ formed by urea hydrolysis. A greenhouse study was conducted to evaluate the effectiveness of oxidized charcoal (OCh; 150 g kg-1 fertilizer) applied with or without Cu and/or Zn (~0.5-2 g kg-1 fertilizer), and of Cu and/or Zn applied without OCh, for increasing uptake of urea 15N by a common tropical pasture grass, capim-Mombaça (Panicum maximum Jacq. Cv. Mombaça), grown on a coarse-textured Oxisol. Cuttings were collected 5, 14, 28, 42, and 56 days after surface placement of amended or unamended urea pellets to estimate dry matter production, total N uptake, and 15N recovery. Soil sampling was carried out in conjunction with the first and fourth cuts to evaluate exchangeable NH4+ and NO3- concentrations. At the concentrations studied, OCh was more effective than Cu and/or Zn for prolonging NH4+-N availability in urea-treated soil; however, OCh alone or in combination with Zn and Cu had no effect on biomass production or N recovery and can safely be eliminated as a useful option for pasture improvement. The most promising amendment was Zn, which significantly increased total N uptake and the efficiency of urea N fertilization. The use of Zn in conjunction with urea has practical potential to improve forage production on tropical soils.
KW - Forage production
KW - N
KW - Urease inhibitors
KW - Zn fertilization
KW - Zn-N synergism
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U2 - 10.1016/j.agee.2016.03.036
DO - 10.1016/j.agee.2016.03.036
M3 - Article
AN - SCOPUS:84962701221
SN - 0167-8809
VL - 224
SP - 157
EP - 165
JO - Agriculture, Ecosystems and Environment
JF - Agriculture, Ecosystems and Environment
ER -