Frost killed cover crops induced high emissions of nitrous oxide.

Autor: Olofsson F; Swedish University of Agricultural Sciences, Department of Biosystems and Technology, P.O. Box 190, SE-234 22 Lomma, Sweden., Ernfors M; Swedish University of Agricultural Sciences, Department of Biosystems and Technology, P.O. Box 190, SE-234 22 Lomma, Sweden. Electronic address: maria.ernfors@slu.se.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Sep 01; Vol. 837, pp. 155634. Date of Electronic Publication: 2022 May 02.
DOI: 10.1016/j.scitotenv.2022.155634
Abstrakt: Establishing a cover crop after harvest of a main crop in late summer or early autumn can have several advantages, including weed control, decreased nitrate leaching and an increased potential for carbon sequestration. However, the addition of fresh plant material to the soil in late autumn or winter, either by active termination of the cover crop or by frost damage, could be a risk factor for nitrous oxide emissions, due to the simultaneous occurrence of wet soil conditions and freeze-thaw cycles. We measured field emissions of nitrous oxide from three cover crops - oilseed radish, (Raphanus sativus var. oleiformis), phacelia (Phacelia tanacetifolia) and oats (Avena sativa) - over a 43-day period in winter. All three cover crops were sensitive to frost and died, wilted and started to decompose during this period. The cover crops increased nitrous oxide emissions, relative to controls that were ploughed in autumn, by 1.8, 0.7 and 0.6 kg N 2 O-N ha -1 , for oilseed radish, phacelia and oats, respectively. We conclude that the choice of cover crop species and management options for cover crops need to be further researched to minimise their contribution to nitrous oxide emissions from agriculture.
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 © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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