Soil Mineral Nitrogen Concentrations Do Not Affect the Ability of Plantain ( <i>Plantago lanceolata</i> L.) to Reduce Nitrous Oxide Emissions From Cattle Urine Patches

ABSTRACT Background Results to date on the effectiveness of plantain ( Plantago lanceolata L.) use as a nitrous oxide (N 2 O) mitigation tool have been variable. In this context, soil mineral N and water content might be factors regulating plantain effectiveness in reducing N 2 O emissions. Aims We, therefore, hypothesized that (1) plantain's ability to reduce N 2 O emissions from urine patches declines as soil N availability increases, and (2) this reduction depends on lower water‐filled pore space (WFPS) induced by plantain. Methods In a glasshouse trial, we assessed the influence of soil N fertility (low N, median N, and high background soil mineral N) and soil moisture content (60% WFPS and simulated rainfall regime) on the effectiveness of plantain to reduce N 2 O emissions. The static chamber method was used to measure N 2 O fluxes following the application of cattle urine (534 kg N ha −1 ) to pots containing either plantain or perennial ryegrass ( Lolium perenne L.). Results Plantain reduced N 2 O emissions and N 2 O emission factors by 42% and 43%, respectively, compared to ryegrass. Neither differences in background soil mineral N concentrations nor soil moisture conditions at 60% WFPS relative to a simulated rainfall regime influenced the plantain's ability to reduce N 2 O emissions. Conclusion Our hypothesis that increasing background soil N concentrations reduces plantain's ability to mitigate N 2 O emissions from cattle urine was rejected. The data also suggest that differences in soil moisture did not influence the effectiveness of plantain in lowering N 2 O emissions.