Journal article
Soil N2O flux and nitrification and denitrification gene responses to feed-induced differences in the composition of dairy cow faeces



Publication Details
Authors:
Meyer, S.; Grüning, M.; Beule, L.; Karlovsky, P.; Jörgensen, R.; Sundrum, A.
Publication year:
2021
Journal:
Biology and Fertility of Soils
Pages range:
767-779
Volume number:
57
ISSN:
0178-2762

Abstract

Faeces from cows with different milk yield and non-lactating cows were applied to soil to investigate whether soil N2O
efflux is related to feeding-induced differences in faecal microbiome
and abundances of nitrification and denitrification genes. Fungal
18S-rRNA gene abundance was the highest in the faeces of the
non-lactating group. The 18S-rRNA/ergosterol ratio showed a strong
positive correlation with the 18S-rRNA/fungal glucosamine ratio. The
milk-yield groups did not affect the gene abundances of bacterial 16S
rRNA, AOB amoA, nirS and nosZ clade I, or the 16S-rRNA/muramic acid (MurN) ratio. In contrast, nirK
gene abundance was generally the lowest in the high-yield group. The
16S-rRNA/MurN ratio showed a strong positive correlation with the
16S-rRNA/bacterial PLFA ratio. Cow faeces application to soil increased
microbial biomass and ergosterol contents as well as the gene abundances
of 18S-rRNA and nosZ clade I, compared with the non-amended control soil. Cumulative ΣCO2 efflux was roughly twice as high as the control, without differences between the faeces treatments. Cumulative ΣN2O
efflux showed a 16-fold increase after applying high-yield cow faeces
to soil, which was above the sevenfold increase in the non-lactating
faeces treatment. The ΣN2O efflux from soil was positively related to faecal MurN and total PLFA concentration but also to soil nirK
at day 14. The comparison of genome markers with cell wall
(glucosamine) and cell membrane components (ergosterol) showed that the
fungal cells were much larger in energy-rich faeces than in C-limited
soil. A cow diet reduced in protein decreased the ΣN2O efflux from faeces amended soil.


Last updated on 2021-16-09 at 09:20