Effets combinés du compost, du Paraquat et de la Lambdacyhalothrine sur la macrofaune du sol sous culture pluviale de sésame ( Sesamum indicum L.) au Burkina Faso

Les pesticides chimiques de synthese utilises pour l’intensification des systemes de production agricoles peuvent affecter de facon defavorable la qualite du sol a travers leur effet sur sa macrofaune. La presente etude a permis d’evaluer les effets synergiques du Paraquat et de la Lambdacyhalothrine en presence du compost sur la macrofaune du sol sous culture pluviale de sesame en milieu paysan, dans la region du Centre-Est du Burkina Faso. La methode « Tropical Soil Biology and Fertility » (TSBF) a ete utilisee pour evaluer l’abondance et la diversite de la macrofaune du sol apres application de pesticides et de compost. L’etude a ete menee entre 2014 et 2015 sur des monolithes de sols preleves a des profondeurs de 0-10 cm et 10-30 cm 3 jours avant semis, au 41 eme et au 81 eme jours apres semis. Les resultats obtenus montrent qu’en absence de pesticide, le compost a entraine une augmentation du nombre d’individus de la macrofaune du sol de 84,14% et de 173,46% respectivement dans les profondeurs de 0-10 cm et 10-30 cm du sol par rapport au temoin non traite. Il ressort aussi que le compost est plus favorable au developpement equilibre et diversifie des groupes de macrofaune. Apres traitement des parcelles par le Paraquat et la Lambdacyhalothrine, une diminution de 47,56% de la macrofaune du sol a ete notee a la profondeur de 0-10 cm du sol et leur elimination totale a ete observee a la profondeur 10-30 cm. © 2017 International Formulae Group. All rights reserved. Mots cles: Paraquat, Lambdacyhalothrine, Sesamum indicum L., macrofaune du sol English Title: Combined effects of compost, Paraquat and Lambdacyhalothrine on soil macrofauna under rainfed crop of sesame ( Sesamum indicum L.) in Burkina Faso English Abstract Synthesis chemical pesticides used for the intensification of agricultural production systems may affect adversely the quality of the soil through their effect on its macrofauna and its microflora. The present study aimed at evaluating the synergistic effects of Paraquat and Lambdacyhalothrin in the presence of the compost on macrofauna of the soil under rainfed crop of sesame in peasant community, in the central east region of Burkina Faso. The method "Tropical Soil Biology and Fertility" (TSBF) has been used to assess the abundance and diversity of macrofauna of soil after application of pesticides and compost. To do so, monoliths of soils at depths of 0-10 cm and 10-30 cm 3 days before seeding, at the 41 th and 81 th days after seedlings have been collected. The results showed that in the absence of pesticide, compost has led to an increase of the population of macrofauna in the soil by 84.14% and 173.46% respectively in the depths of 0-10 cm and 10-30 cm of the soil compared with the none treated sample. It is also clear that the compost is more favorable with the development of well-balanced and diversified groups of macrofauna. After treatment of plots by Paraquat and Lambdacyhalothrin, a decrease of 47.56% of the soil macrofauna has been recorded at the depth of 0-10 cm of the soil and their total elimination was observed at the depth of 10-30 cm. © 2017 International Formulae Group. All rights reserved. Keywords: Paraquat, Lambdacyhalothrine, Sesamum indicum L., Soil macrofauna