Nitrous oxide emission factors in conventionally and naturally simulated cattle urine patches.

Autor: O'Neill, M., Saggar, S., Richards, K. G., Luo, J., Singh, B. P., Mehra, P., Forrestal, P. J.
Zdroj: Nutrient Cycling in Agroecosystems; Dec2021, Vol. 121 Issue 2/3, p129-147, 19p
Abstrakt: We quantified nitrous oxide emission factors (N2O EFs) for cattle urine patches established using two simulation methods: (1) a uniformly wetted area (UWA) and (2) a naturally expanding effective area (NEEA). Field experiments were conducted on long-term grasslands in New Zealand (NZ1 and NZ2) and Ireland (IRE) for varying urine nitrogen (N) application rates in two initial soil moisture regimes (below field capacity and field capacity). Nitrous oxide emissions were measured using static chambers for a period of 120, 133 and 85 days at NZ1, NZ2 and IRE, respectively. Nitrous oxide EFs were unaffected by patch type (UWA = 0.99%; NEEA = 1.07%) across varying urine N application rates in NZ1 whereas in NZ2, EFs varied with urine N application rate only for the NEEA patches in below field capacity soils (P < 0.05). In IRE, we observed a ~ fourfold difference in the mean N2O EF between the UWA (0.67 ± 0.24%) and NEEA (0.18 ± 0.04%) patches in below field capacity soils (P < 0.05) but no significant differences in EFs were detected between the UWA (0.75 ± 0.14%) and NEEA (0.53 ± 0.08%) patches at field capacity soils. Our study suggests that patch simulation method and initial soil water content can independently affect N2O EFs in urine-affected pasture but factor effects may be largely site and/or soil specific. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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