Biochar Diminishes Nitrous Oxide and Nitrate Leaching from Diverse Nutrient Sources

Abstract

Manure generated by intensive livestock operations poses potential ecological risk in the form of water pollution and greenhouse gas emission. To assess the impact of biochar on coarse-textured soils under contrasting nutrient management regimes, a 55-d incubation was conducted using unplanted soil columns amended with manure, slurry, or fertilizer (plus unamended control), each with or without biochar applied at 2% soil mass (dry weight basis). Under repeated leaching, the cumulative NO emission from the columns was significantly affected by the presence of biochar ( < 0.0001), although these data were not normally distributed. Results indicated that the biochar-amended soils emitted significantly less NO than their unamended counterparts, with the exception of manure-amended soils. The presence of biochar increased the pH of column leachate by 0.08 to 1.70 and significantly decreased the cumulative amount of mineral N leached from the soil. The presence of biochar significantly increased the amount of PO-P in soil leachate, but there was no significant difference between the means for any of the amendments used on their own relative to their biochar-amended counterparts. The data demonstrate that biochar could potentially aid in the mitigation of NO emissions from certain soils and in N loss in leachate from soil amended with slurry, manure, or fertilizer used in livestock systems.

Can biochar provide ammonium and nitrate to poor soils?: Soil column incubation

“…Many studies that have suggested that biochar addition reduces the loss of NO 3 − -N via leaching or increases soil accumulation were conducted over relatively short incubation periods (days to months) (Novak et al, 2010;Angst et al, 2013;Eykelbosh, 2015;Xu et al, 2016) …”

Effects of biochar on nitrous oxide and nitric oxide emissions from paddy field during the wheat growth season

“…Cayuela et al (2013) demonstrated that biochar increased soil pH and subsequently promoted the reduction of N 2 O to N 2 . Meanwhile, biochar could absorb soil NH 4 þ or NO 3 À , which in turn would decrease the availability of mineral N (Angst et al, 2013;Case et al, 2012;van Zwieten et al, 2010) and enhance soil aeration (Rogovska et al, 2011).…”

Producing energy while sequestering carbon? The relationship between biochar and agricultural productivity

“…Another potential mechanism for decreased N 2 O emissions in biochar-amended soils may be an increased adsorption of ammonium cations (NH + 4 ) and/or N-containing organic compounds, which reduce both N leaching and N 2 O emissions (Singh et al, 2010). While most studies have shown reductions in N 2 O emissions for soils amended with biochar relative to control soils (Angst et al, 2013;Cayuela et al, 2013), no significant differences and even small increases between biochar-amended soil and controls in N 2 O emissions have been reported (Karhu et al, 2011;Scheer et al, 2011).…”