The effects of humic acid urea and polyaspartic acid urea on reducing nitrogen loss compared with urea.

Shen, Yuwen; Lin, Haitao; Gao, Wensheng; Li, Mingli

BACKGROUND The utilization rate of urea-N in fertilizer plays a very important role in agricultural production and environmental protection. Humic acid urea (HAU) and polyaspartic acid urea (PAU) are two similar synergistic nitrogen fertilizers. METHODS Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD) and 13 C-nuclear magnetic resonance (13 CNMR) were used to determine the loading of urea-N into the humic acid (HA) and polyaspartic acid (PA). Thermal stability and physical adsorption properties of HAU and PAU were assessed by thermogravimetric analysis (TGA) and Brunauer Emmett Teller (BET) surface measurement. The soil incubation experiment was conducted to investigate the effects of HAU and PAU on nitrogen transformation and gaseous nitrogen loss compared with commercial urea. RESULTS Nitrogen transformation from FAU and PAU was slowed down compared with urea. After 90 days of incubation, HAU and PAU reduced the cumulative NH3 volatilization (by 9.70% and 6.30%, respectively) and N2 O emission (by 40.48% and 43.00%, respectively) from soil compared with the urea-alone treatment. CONCLUSION HAU and PAU could improve the nitrogen use efficiency. This article is protected by copyright. All rights reserved.