Elevating soil pH does not reduce N2O emissions from urine deposited onto pastoral soils. Issue 6 (2nd November 2022)

• Record Type: Journal Article
• Authors: van der Weerden, Tony J.; Rutherford, Alison J.; de Klein, Cecile A.M.; Ganasamurthy, Syaliny; Morales, Sergio E.
• Is Part Of: New Zealand journal of agricultural research. Volume 65:Issue 6(2022)
• Page Start: 484
• Page End: 506
• Publication Date: 2022-11-02
• Subjects: Denitrification -- lime -- inorganic-N -- urea -- CEC; Agriculture -- Periodicals; Agriculture -- New Zealand -- Periodicals; Animal culture -- Periodicals; Animal culture -- New Zealand -- Periodicals; 630.99305
• DOI: 10.1080/00288233.2021.1935280
• Languages: English
• ISSNs: 0028-8233

Abstract

ABSTRACT: Urine deposited onto grazed pastures is the main source of anthropogenic nitrous oxide (N2 O) in New Zealand. Low soil pH ( ca 5.0) has been linked to increases in the proportion of N2 O to N2 emitted through soil denitrification. However, total denitrification rates and N2 O emissions can increase with soil pH up to ca 7.0–8.0. We conducted an incubation experiment and a field study to examine the potential to mitigate total N2 O emissions from urine deposition by increasing the soil pH through liming. The incubation study used three different soils where the pH was adjusted to 6.5, 6.9 and 7.4. Cumulative N2 O emissions following synthetic urine application at 630 kg N ha −1 increased with increasing soil pH. The field study, where soil pH was adjusted to 6.6, 7.0 and 7.1, had synthetic urine applied one year later at 600 kg N ha −1 . Within the pH range studied, increasing pH did not have a significant effect on N2 O emissions following urine application. Both experiments suggest adjusting soil pH from ca 6 to ca 7 is not an effective tool for reducing N2 O emissions from urine patches.