Unintentional effects of environmentally-friendly farming practices: Arising conflicts between zero-tillage and a crop pest, the common vole (Microtus arvalis)

Deon Roos,Constantino Caminero Saldaña,Beatriz Arroyo,François Mougeot,Juan José Luque-Larena,Xavier Lambin

doi:10.1016/j.agee.2018.11.013

Abstract

Common voles are a main European facultative, fossorial, farmland rodent pest that can greatly reduce crop yields during population outbreaks. Crop protection against common voles is a complex task that requires the consideration of a set of preventive and control measures within an integrated pest management strategy. A possible option could be to modify farming practices to reduce the availability of refuges for rodents and the damage to crops that they subsequently cause. Farming, however, must simultaneously meet multiple goals including the reduction of the carbon (C) emissions, soil erosion and water use, and the improvement of soil quality. Crop establishment through conservation agriculture strategies, like zero-tillage, would reduce crop management investment, but is also promoted in many regions to reduce C emissions and increase soil organic matter. It could, however, create favourable refuge habitats for fossorial rodent crop pests, like common voles, benefitting from reduced soil disturbance between crop rotations and thus increasing burrow persistence. Assessing the impact that tillage practices, their interaction with different crops and the influence of proximity to potential common vole sources, have on common vole occupancy could provide a valuable tool within an integrated management strategy. Using a 2-ha experimental field with 62 plots 180 m2 (each roughly matching common vole home range size) located experimental plots in north-western Spain, we tested how tillage practices, crop type (wheat, barley, vetch, Narbonne vetch, pea and fallow) and distances from possible colonization sources affect field use by common vole during low population density conditions. Our results show that tillage practices have more influence on common vole occurrence (zero tillage > reduced and conventional tillage) than other aspects such as crop type thus supporting the hypothesis that tillage practices play a key role in common vole habitat use.

Highlights

The increasing global human population necessitates a commensurate increase in crop yields, all the while doing so in increasingly difficult scenarios presented by climate change (Lobell et al, 2008)
Tillage practice Common vole activities were only detected in ZT plots
The results suggested that initial occupancy was constant and not explained by tillage type, crop type or distance from field margin, whereas colonisation was only explained by month but not by the number of adjacent occupied plots

Summary

Introduction

The increasing global human population necessitates a commensurate increase in crop yields, all the while doing so in increasingly difficult scenarios presented by climate change (Lobell et al, 2008). Concerns regarding impacts on biodiversity (Tilman et al, 2011), carbon (C) and nitrogen (N) emissions (Smith et al, 2005; Tilman and Clark, 2014), or water retention (Bescansa et al, 2006; Freibauer et al., 2004) must be balanced with the need for increased yields, with no generic win-win scenarios being apparent. In order to achieve these aims, various trade-offs must be managed concerning the competing interests. One approach to achieve these multiple aims is through the use of agricultural conservation practices which are considered to be environmentally sensitive and economically viable (Soane et al, 2012). An increasingly widely used conservation practice is zero-tillage

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Discussion

Conclusion