title: Efficiency of urease and nitrification inhibitors in reducing ammonia volatilization from diverse nitrogen fertilizers applied to different soil types and wheat straw mulching.
abstract: BACKGROUND
  Some authors suggest that the absence of tillage in agricultural soils might have an influence on the efficiency of nitrogen applied in the soil surface. In this study we investigate the influence of no-tillage and soil characteristics on the efficiency of a urease inhibitor (N-(n-butyl)thiophosphoric triamide, NBPT) and a nitrification inhibitor (diciandiamide, DCD) in decreasing ammonia volatilization from urea and ammonium nitrate (AN), respectively.
  
  
  RESULTS
  The results indicate that ammonia volatilization in soils amended with urea was significantly higher than in those fertilized with AN. Likewise, the main soil factors affecting ammonia volatilization from urea are clay and sand soil contents. While clay impedes ammonia volatilization, sand favours it. The presence of organic residues on soil surface (no-tillage) tends to increase ammonia volatilization from urea, although this fact depended on soil type. The presence of NBPT in urea fertilizer significantly reduced soil ammonia volatilization. This action of NBPT was negatively affected by acid soil pH and favoured by soil clay content.
  
  
  CONCLUSIONS
  The presence of organic residues on soil surface amended with urea increased ammonia volatilization, and was particularly high in sandy compared with clay soils. Application of NBPT reduced ammonia volatilization although its efficiency is reduced in acid soils. Concerning AN fertilization, there were no differences in ammonia volatilization with or without DCD in no-tillage soils.
authors.affiliation: CIPAV-TAI Roullier Group, Poligono Arazuri-Orkoien, 31160 Orkoien, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: San Francisco
authors.forename: Oscar
authors.initials: O
authors.lastname: Urrutia
authors.forename: Vincent
authors.initials: V
authors.lastname: Martin
authors.forename: Angelos
authors.initials: A
authors.lastname: Peristeropoulos
authors.forename: Jose Maria
authors.initials: JM
authors.lastname: Garcia-Mina
mesh_terms: D000383:Agriculture / Q000379:methods; D000538:Aluminum Silicates; D000641:Ammonia / Q000378:metabolism*; D000077215:Clay; D004791:Enzyme Inhibitors; D005308:Fertilizers; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000378:metabolism; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D009943:Organophosphorus Compounds; D018547:Plant Stems; D012822:Silicon Dioxide; D012987:Soil; D014908:Triticum; D014508:Urea / Q000378:metabolism; D014510:Urease / Q000037:antagonists & inhibitors*; D014835:Volatilization
chemical_list: D000538:Aluminum Silicates; D004791:Enzyme Inhibitors; D005308:Fertilizers; D006812:Humic Substances; C120049:N-(n-butyl) thiophosphoric triamide; D009566:Nitrates; D009943:Organophosphorus Compounds; D012987:Soil; D012822:Silicon Dioxide; D000641:Ammonia; D014508:Urea; D014510:Urease; D009584:Nitrogen; D000077215:Clay; C006568:ammonium nitrate