1. Beneficial effects of multi-species mixtures on N 2 O emissions from intensively managed grassland swards.
- Author
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Cummins S, Finn JA, Richards KG, Lanigan GJ, Grange G, Brophy C, Cardenas LM, Misselbrook TH, Reynolds CK, and Krol DJ
- Subjects
- Fertilizers analysis, Nitrogen, Nitrous Oxide analysis, Poaceae, Grassland, Soil
- Abstract
In a field experiment, annual nitrous oxide (N
2 O) emissions and grassland yield were measured across different plant communities, comprising systematically varying combinations of monocultures and mixtures of three functional groups (FG): grasses (Lolium perenne, Phleum pratense), legumes (Trifolium pratense, Trifolium repens) and herbs (Cichorium intybus, Plantago lanceolata). Plots received 150 kg ha-1 year-1 nitrogen (N) (150 N), except L. perenne monocultures which received two N levels: 150 N and 300 N. The effect of plant diversity on N2 O emissions was derived from linear combinations of species performances' in monoculture (species identity) and not from strong interactions between species in mixtures. Increasing from 150 N to 300 N in L. perenne resulted in a highly significant increase in cumulative N2 O emissions from 1.39 to 3.18 kg N2 O-N ha-1 year-1 . Higher N2 O emissions were also associated with the legume FG. Emissions intensities (yield-scaled N2 O emissions) from multi-species mixture communities around the equi-proportional mixture were lowered due to interactions among species. For N2 O emissions scaled by nitrogen yield in forage, the 6-species mixture was significantly lower than L. perenne at both 300 N and 150 N. In comparison to 300 N L. perenne, the same N yield or DM yield could have been produced with the equi-proportional 6-species mixture (150 N) while reducing N2 O losses by 63% and 58% respectively. Compared to 150 N L. perenne, the same N yield or DM yield could have been produced with the 6-species mixture while reducing N2 O losses by 41% and 24% respectively. Overall, this study found that multi-species grasslands can potentially reduce both N2 O emissions and emissions intensities, contributing to the sustainability of grassland production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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