Effect of a new urease inhibitor on ammonia volatilization and nitrogen utilization in wheat in north and northwest China

• Published in: Field crops research Vol. 175; pp. 96 - 105
• Main Authors: Li, Qianqian, Yang, Ailing, Wang, Zhaohui, Roelcke, Marco, Chen, Xinping, Zhang, Fusuo, Pasda, Gregor, Zerulla, Wolfram, Wissemeier, Alexander H., Liu, Xuejun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2015
• Subjects: Grain yields; Limus; N budgets; N recovery efficiency; NH3 losses; Urea; NH3 losses; Urea; N recovery efficiency; N budgets; Limus; Grain yields
• ISSN: 0378-4290; 1872-6852
• DOI: 10.1016/j.fcr.2015.02.005

•Ammonia volatilization was measured by calibrated Dräger-Tube method at three sites.•NH3 losses were 11–25% of applied N in wheat under conventional urea treatment.•Limus (a urease inhibitor) reduced NH3 losses by 83% compared with conventional urea.•Limus can save 20% of urea N to achieve same wheat yield as optimized N treatments. Field experiments were conducted at three typical wheat–maize double-cropping sites in north and northwest China to investigate ammonia (NH3) volatilization from urea and from urea amended with 0.12% (w/w) Limus® (a new urease inhibitor consisting of 75% N-(n-butyl) thiophosphoric triamide (NBPT) and 25% N-(n-propyl) thiophosphoric triamide (NPPT)) in winter wheat. Grain yields and nitrogen (N) budgets of all N treatments were also evaluated to investigate the effects of urea-N application rates and Limus during one wheat season. Cumulative NH3 losses after two weeks for conventional urea were 11–25% of applied N, while those for urea amended with Limus were only 0–6% of applied N. The urease inhibitor increased fertilizer N retention more strongly when soil and environmental conditions promoted extensive NH3 losses. However, grain yields were not significantly (P>0.05) enhanced by Limus compared to conventional urea at all three sites. A clear increase in apparent N recovery efficiency (REN) with Limus (ranging from 10 to 16%) resulted at the Quzhou (QZ) site compared to equal amounts of optimized urea-N, with an increase in REN of up to 65% under a further 20% N-reduced urea amended with Limus treatment. The study also demonstrated the urgency of appropriate fertilizer N management in China.