Abstract
AbstractAmmonia (NH3) volatilization loss adversely affects N availability in soil‐plant systems, reduces crop yield, and negatively impacts environment. Char (coal combustion residue), which contains up to 293 g kg−1 total C by weight, has been shown to reduce NH3 volatilization due to its considerably high surface area and cation exchange capacity. The NH3 loss can be greatly affected by a shift in soil pH or urea hydrolysis. A 21‐d laboratory study was conducted to evaluate the effects of char on soil pH, N transformations, and subsequent NH3 volatilization in sandy loam soil. Two char rates (0 and 13.4 Mg C ha−1) and two urea rates (0 and 200 kg N ha−1) were mixed in soil in four 2‐way combinations with four replications of each. There were 11 sets of all treatment combinations and each set was analyzed for soil moisture, pH, NH3 volatilization, and residual N (urea, NH4, and NO3) every other day for 3 wk. Char application reduced cumulative NH3 loss in the fertilized treatment. Reduction in NH3 loss due to char addition was evidenced by greater residual NH4–N on certain days in treatments with char compared to treatments without char. Char did not affect urea hydrolysis process but it lowered soil pH in the fertilized treatments in the first week. This study supported our hypothesis that char altered soil pH and thereby reduced NH3 volatilization loss from the fertilized soil.
Highlights
A global meta-analysis of 824 observations revealed that up to 64% of surface-applied N fertilizer could volatilize as ammonia (NH3) and be lost from the soils to the atmosphere (Pan, Lam, Mosier, Luo, & Chen, 2016)
Ammonia volatilization accrues as the urea is applied to the soil surface through urea hydrolysis under favorable conditions and this process may continue up to 2 wk (Sommer, Schjoerring, & Denmead, 2004)
Maintaining the incubation temperature (25 ̊C) and soil moisture content around 35% water-filled pore space throughout the experiment period allowed for considerable NH3 volatilization loss
Summary
A global meta-analysis of 824 observations revealed that up to 64% of surface-applied N fertilizer could volatilize as ammonia (NH3) and be lost from the soils to the atmosphere (Pan, Lam, Mosier, Luo, & Chen, 2016). Among all N fertilization type, urea accounted for nearly 56% of global fertilizer N consumption, as it contains comparatively high N content, safe to handle, and readily available in granular or liquid form (IFA, 2017). Ammonia volatilization accrues as the urea is applied to the soil surface through urea hydrolysis under favorable conditions (high soil pH and adequate moisture) and this process may continue up to 2 wk (Sommer, Schjoerring, & Denmead, 2004). Several modifications are applied to urea fertilizers such as adding urease inhibitor [e.g., N-(n-butyl) thiophosphoric triamide (NBPT)]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
