WIZHJ5MS

3064

15 janvier 2021 10:05

7 avril 2021 09:00

Cover crop (CC) mixtures including both legume and non-legume species have the potential to reduce nitrate leaching and increase N availability in the system through biological N2 fixation (BNF). However, the provision of multiple services depends on the biomass expression of functionally diverse species. Cover crop growth can be manipulated through management, but more knowledge is needed on species expression, and the effects on nitrate leaching and BNF. We investigated this in a long-term organic crop rotation experiment, where an undersown legume-based CC mixture, composed of perennial ryegrass (Lolium perenne L.), chicory (Chicorium intybus L.), white clover (Trifolium repens L.) and red clover (Trifolium pratense L.), was grown under different cropping system and fertility management in three consecutive years. We found a linear complementary relation between legume and non-legume biomass when CC growth was the greatest. Non-legume biomass was high under non-N-limiting conditions, while legume biomass and N input via BNF were high where the risk of nitrate leaching was low, as shown by the low and stable nitrate leaching above a threshold of 0.4 Mg clover DM ha−1. Above this threshold, the percentage of N derived from the atmosphere (%Ndfa) was high and stable (91 %), while lower and more variable with lower legume biomass. Overall, our results show that legume-based CC mixtures are self-regulating in terms of nitrate leaching reduction and N input via BNF.

None

• AB - Spécifique
• drainage water
• FREDO biologie et travail du sol
• FREDO environnement
• GEO Danemark
• couvert végétal

• biological nitrogen fixation
• catch crop
• functional diversity
• species expression

Agriculture, Ecosystems & Environment

309

107287

April 1, 2021

1 avril 2021

10.1016/j.agee.2020.107287 Le DOI est une URL unique de référencement d'une publication. Il est donc plus fiable et permanent qu'une URL classique

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