Yuwen Shen1,2, Haitao Lin1, Wensheng Gao3, Mingli Li3. 1. Institute of Agricultural Resources and Environment, Key Laboratory of Wastes Matrix Utilization, Ministry of Agriculture, Shandong Provincial Engineering Research Center of Environmental Protection Fertilizers, Shandong Academy of Agricultural Sciences, Jinan, P. R. China. 2. State Key Laboratory of Nutrition Resources Integrated Utilization, Linshu, P. R. China. 3. Shandong Agriculture Department, Fruit and Tea Technique Extension Station, Jinan, P. R. China.
Abstract
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 (FTIR), X-ray powder diffraction (XRD) and carbon-13-nuclear magnetic resonance (13 C-NMR) were used to determine the loading of urea-N into 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 HAU and PAU was slowed down compared with urea. After 90 days of incubation, HAU and PAU reduced the cumulative ammonia (NH3 ) volatilization (by 9.70% and 6.30%, respectively) and nitrous oxide (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.
BACKGROUND: The utilization rate of urea-N in fertilizer plays a very important role in agricultural production and environmental protection. Humic acidurea (HAU) and polyaspartic acidurea (PAU) are two similar synergistic nitrogen fertilizers. METHODS: Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and carbon-13-nuclear magnetic resonance (13 C-NMR) were used to determine the loading of urea-N into 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 HAU and PAU was slowed down compared with urea. After 90 days of incubation, HAU and PAU reduced the cumulative ammonia (NH3 ) volatilization (by 9.70% and 6.30%, respectively) and nitrous oxide (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.