Is there a synergy between hedges and intercrops for pest biocontrol ? - Archive ouverte HAL Accéder directement au contenu
Poster De Conférence Année : 2013

Is there a synergy between hedges and intercrops for pest biocontrol ?

Résumé

A major challenge for agroecology is to identify alternative cropping systems that can both ensure sufficient levels of food production and reduction in pesticide inputs while maintaining ecosystem integrity and simultaneously delivering multiple ecosystem services. Among ecological services, biocontrol of pests by natural enemies could be improved by effective management of semi-natural elements in landscape such as hedgerows (Landis et al., 2000). Another way to reduce pest populations in fields consists in increasing diversity of crop species both in time and space. A practice such as intercropping that creates structures of mixed plant populations with "barrier" or "dilution of resources" effects (Médiène et al., 2011) can reduce the pressure of pathogens, weeds and pests compared with that exerted on sole crops (Letourneau et al., 2011). While the combination of these two kinds of practices designed to strengthen auxiliary communities often appears efficient and could result in a synergy, many cases of study show opposite results (e.g. Straub and Snyder, 2006). Our study aimed at quantifying and comparing the efficiency of both hedgerow and intercropped pea and wheat on pest biocontrol in a field. We examined i) the potential role of different types of field edges (with and without an hedgerow) on biological control of weed seeds, aphids, pea weavils and eggs of Sitona lineatus, ii) the effect of intercropping on the biological control of these pests compared with sole crops and iii) the interaction between the two factors. We conducted both field surveys of pest abundance and pest biocontrol effectiveness by estimating predation rates by using seeds and prey sticked on cards. We found that aphid density was slightly lower in pea-wheat intercrops than in sole crops, and was influenced by the distance from the field edge (whatever the kind of edges). However, neither the hedgerow nor the intercrop situation favored aphid predation. The density of weeds did not vary according to the cropping system and distance from the field edge. We showed that the predation rate of weed seeds or of Sitona lineatus eggs and the parasitism of Bruchus pisorum decreased according to the distance to the hedge in sole crops but increased in the intercrop. This study points out the absence of a global synergy between intercrops and hedges in supporting pest and weed regulation: the regulation efficiency varied according to pest species. This study calls for a deepened multi-species approach in order to find trade-offs between agricultural practices and field edge management to optimize regulating ecosystem services such as pest biocontrol.
Fichier principal
Vignette du fichier
2013_Alignier_Poster_2013_11th_International_association_for_ecology_congress_1.pdf (1.01 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-01601774 , version 1 (06-06-2020)

Identifiants

  • HAL Id : hal-01601774 , version 1
  • PRODINRA : 387427

Citer

Audrey Alignier, Emilie Andrieu, Laurent Bedoussac, Etienne-Pascal Journet, Annie Ouin, et al.. Is there a synergy between hedges and intercrops for pest biocontrol ?. 11. International Association for Ecology congress, Aug 2013, Londres, United Kingdom. 1 p., 2013. ⟨hal-01601774⟩
96 Consultations
10 Téléchargements

Partager

Gmail Facebook X LinkedIn More