https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46327 3^ˉ) reduction by DNRA and denitrification. Soil samples were incubated at 10 to 40 °C for 28 days, and ¹⁵N tracer methods were applied to estimate the reduction of ¹⁵NO₃^ˉ to ¹⁵NH₄⁺ by DNRA organisms and to ¹⁵N₂O or ¹⁵N₂ by denitrifiers. Raising the temperature from 10 to 40 °C increased DNRA, which contributed to enrichment of the NH₄⁺ pool, particularly at 40 °C. The percentage of ¹⁵NO₃^ˉ, reduced by DNRA was from 4 to 30% of that reduced by denitrification, and decreased with increasing temperature. DNRA and denitrification were positively correlated with the abundance of nrfA and nosZ genes, respectively. The accumulation of ¹⁵NH₄⁺ slowed in the final 12 h of sampling times, which may be due to a re-conversion of ¹⁵NH₄⁺ to ¹⁵NO₃^ˉ by nitrification. High temperatures (30 to 40 °C) enhanced ¹⁵N₂ production, which suggests that temperature plays an important role in regulating complete denitrification from NO₃^ˉ to N₂.]]> Tue 15 Nov 2022 12:20:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38226 75 μm), was 13.4% higher under CT, but mesoporosity (30–75 μm) was 9.6% higher under NT. The vertical distributions of root biomass and root architecture measurements (i.e. root length density) in undisturbed soil cores were 9.6% higher under the NT and 8.7% higher under the CT system respectively. These results suggest that low soil disturbance under the continuous NT system may have encouraged accumulation of more root biomass in the top 100 mm depth, thus developing better soil structure. Overall, µXCT image analyses of soil cores indicated that this tillage shift affected the soil total carbon, due to the significantly higher soil-pore (i.e. pore surface area, porosity and average pore size area) and root architecture (i.e. root length density, root surface density and root biomass) measurements under the CT system.]]> Mon 16 Aug 2021 15:47:54 AEST ]]>