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Lumaret J.-P.,CNRS Center of Evolutionary and Functional Ecology | Errouissi F.,UR Biodiversite et Biologie des Populations | Floate K.,Agriculture and Agri Food Canada | Rombke J.,ECT Oekotoxikologie GmbH | Wardhaugh K.,11 Deane Street
Current Pharmaceutical Biotechnology | Year: 2012

The avermectins, milbemycins and spinosyns are collectively referred to as macrocyclic lactones (MLs) which comprise several classes of chemicals derived from cultures of soil micro-organisms. These compounds are extensively and increasingly used in veterinary medicine and agriculture. Due to their potential effects on non-target organisms, large amounts of information on their impact in the environment has been compiled in recent years, mainly caused by legal requirements related to their marketing authorization or registration. The main objective of this paper is to critically review the present knowledge about the acute and chronic ecotoxicological effects of MLs on organisms, mainly invertebrates, in the terrestrial and aquatic environment. Detailed information is presented on the mode-of-action as well as the ecotoxicity of the most important compounds representing the three groups of MLs. This information, based on more than 360 references, is mainly provided in nine tables, presenting the effects of abamectin, ivermectin, eprinomectin, doramectin, emamectin, moxidectin, and spinosad on individual species of terrestrial and aquatic invertebrates as well as plants and algae. Since dung dwelling organisms are particularly important non-targets, as they are exposed via dung from treated animals over their whole life-cycle, the information on the effects of MLs on dung communities is compiled in an additional table. The results of this review clearly demonstrate that regarding environmental impacts many macrocyclic lactones are substances of high concern particularly with larval instars of invertebrates. Recent studies have also shown that susceptibility varies with life cycle stage and impacts can be mitigated by using MLs when these stages are not present. However information on the environmental impact of the MLs is scattered across a wide range of specialised scientific journals with research focusing mainly on ivermectin and to a lesser extent on abamectin doramectin and moxidectin. By comparison, information on compounds such as eprinomectin, emamectin and selamectin is still relatively scarce. © 2012 Bentham Science Publishers.

Errouissi F.,UR Biodiversite et Biologie des Populations | Errouissi F.,Institute Superieur Des Science Biologiques Appliquees Of Tunis | Ben Moussa-Machraoui S.,Institute Superieur Des Science Biologiques Appliquees Of Tunis | Ben-Hammouda M.,Ecole Superieure dAgriculture du Kef ESAK | And 2 more authors.
Soil and Tillage Research | Year: 2011

One of the challenges of research in soil ecology is to assess the impact of tillage managements on soil invertebrates. It is known that tillage practices change soil water content, temperature, the degree of mixing of crop residues within the soil matrix and the physico-chemical environment for soil organisms. The present study tested whether no-tillage (NT) or a conventional tillage (CT) of a cereal (durum wheat; Triticum durum) field in a semi-arid zone of northwestern Tunisia could improve the biological activity and diversity of soil invertebrates, especially arthropod and earthworm communities. The experiment was conducted in January 2000 at two different sites (Mahasse/Kef Governorate and Krib/Siliana Governorate). Soils (Brunisols, isohumic or fersialitic soil) were silt/clay in Mahessen and sand/clay in Krib. After three and four years, soil fauna was sampled with two methods (quadrat and pitfall trap) over 7 months for the last two growing seasons (2002/2003 and 2003/2004). We hypothesized that: (i) soil fauna richness, abundance and diversity would be lower in CT soils than in NT soils and (ii) the move from CT to NT may improve the soil biological component under semi arid conditions.380 invertebrates (37 species) and 309 invertebrates (24 species) were collected by quadrat and pitfall trap methods, respectively. NT greatly enhanced the species richness (from 26 species in CT to 34 species in NT) and abundance (from 61 individuals in CT to 319 individuals in NT) of soil invertebrates with quadrat method. Only abundance was significantly enhanced with pitfall trap method (from 78 individuals in CT to 235 individuals in NT). So, abundance, species richness and diversity of soil arthropods were significantly higher (P< 0.05) with NT than with CT. Soil fauna patterns showed that management mode affected also the abundance of earthworm community. These findings confirm our first hypothesis. Predators (mostly Carabidae), detritivore (especially: Formicidae, Dolicoderidae, Lumbricidae) and herbivore (represented here by Julidae, Pyrrhochridae and some Scarabaeidae) were significantly (P< 0.05) more abundant with NT than with CT. The biological index V (index which compares the relative increase or decrease of the population density between the two tillage modes) showed that all major taxonomic groups were extremely inhibited by CT, confirming our second hypothesis.So, NT seems to be beneficial to biological soil component where it favoured the establishment of diverse soil communities than did CT in durum wheat cropped field. Furthermore, soil fauna may enhance crop-residues decay processes. © 2010 Elsevier B.V.

Ben Moussa-Machraoui S.,Ecole Superieure dAgriculture du Kef ESAK | Errouissi F.,UR Biodiversite et Biologie des Populations | Errouissi F.,Institute Superieur Des Science Biologiques Appliquees Of Tunis | Ben-Hammouda M.,Ecole Superieure dAgriculture du Kef ESAK | And 2 more authors.
Soil and Tillage Research | Year: 2010

No-tillage (NT) is becoming increasingly attractive to farmers worldwide because it clearly reduces production costs relative to conventional tillage (CT) and improves soil properties and crop yield. Currently, under semi-arid conditions in North Africa, modern no-tillage techniques are being practiced on several hectares of land. The effect of NT and CT management and crop rotation on soil properties under semi-arid Mediterranean conditions was studied, over a 4-year period at two locations in northern Tunisia. Data from a short-term (2000-2004) use of both no-tillage (NT) and conventional tillage (CT) at the ESAK (Tunisia) were used to evaluate the influence of the tillage systems on the physicochemical properties of soil at the 0-20 cm depth layers. Trial was set up in 2000, where the two tillage systems (CT and NT), and four crop types (durum wheat, barley, pea and oats) were implemented in two distinct sites close to two governorates: Kef (silt/clayey) and Siliana (sand/clay) in northwestern Tunisia. Four years after implementing the two different tillage systems, soil parameters (N, NO3 2-, NH4 + P, P2O5, K, K2O, SOC, SOM and CEC) were determined and comparison between the two tillage systems was made. Our results showed that after 4 years the contents of some parameters for most crop types were greater under NT than under CT at 0-20 cm depth layers, the results varied depending on crop type and site. NT significantly improved soil content especially for K, K2O, P2O5 and N. Under NT system SOM and SOC were enhanced, but without significant results. These enhancements were accompanied by the enhancement of the CEC and the decrease of the C/N ratio. Thus the mineralization process was slightly quicker under NT. Our results also indicate that residue cover combined with no-tillage appears to improve some agronomic parameters and biomass production (grain yield). Multivariate analyses indicate that the improvement of soil properties was dependant on tillage management, sites (climate and soil type) and crop succession (species and cover residue). It must be pointed out that a 4-year period was not sufficient to clearly establish some parameters used in the effects of the NT system on soil properties under semi-arid conditions in northwestern Tunisia. © 2009 Elsevier B.V. All rights reserved.

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