Effects of plantain in pasture on nitrous oxide emissions from cattle urine patches, as affected by urine deposition timing and soil type
Samantha Earl-Goulet, William D. Talbot, Keith C. Cameron, Hong J. Di
Abstract
ABSTRACT Two lysimeter experiments were conducted to quantify the effect of including plantain in pasture on nitrous oxide (N 2 O) emissions from cattle urine patches, as affected by urine deposition timing and soil type. In experiment one, two pasture types were tested: (i) perennial ryegrass ( Lolium perenne )/white clover ( Trifolium repens ) (PRG/WC), and (ii) perennial ryegrass/white clover/plantain ( Plantago lanceolata ) (PRG/WC/P) pastures, under four urine application dates (late summer, early autumn, mid‐autumn, and late autumn). In experiment two, two pasture types were tested: (i) PRG/WC and (ii) PRG/WC/P on two soil types (Balmoral shallow stony silt loam and Templeton deep stone‐less silt loam). Both experiments applied cow urine (700 kg N ha −1 ) and collected gas samples using a closed chamber method. In experiment one and two, the addition of plantain to pasture had no significant effect on N 2 O‐N emissions. Soil type had no significant effect on N 2 O‐N emissions. However, urine application timing had a significant effect, with February having the highest average N 2 O‐N emissions (9.0 kg N 2 O‐N ha −1 ), followed by March (3.0 kg N 2 O‐N ha −1 ), April (2.7 kg N 2 O‐N ha −1 ) and May (1.7 kg N 2 O‐N ha −1 ). This change in N 2 O‐N emissions is attributed to cooler conditions reducing microbial activity, subsequently reducing nitrification and denitrification rates.