Sammanfattning

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 N2O-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.

Nyckelord

Phacelia; Oilseed radish; Oats; Greenhouse gases; Freeze-thaw; Winter emission

Publicerad i

Science of the Total Environment
2022, Volym: 837, artikelnummer: 155634

SLU författare

• Ernfors, Maria

  • Institutionen för biosystem och teknologi, Sveriges lantbruksuniversitet
    

Associerade SLU-program

SLU Nätverk växtskydd


UKÄ forskningsämne

Jordbruksvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1016/j.scitotenv.2022.155634

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/117205