G. de Snoo

Effect of herbicide drift on adjacent boundary vegetation

Abstract The influence on adjacent ditch-bank vegetation of not spraying crop edges with pesticides was investigated in the Netherlands. To this end, the outer 3–6xa0m of winter wheat, sugar beet and potato fields were left unsprayed with herbicides and insecticides. The presence and abundance of plant species in adjacent ditch-bank vegetation were compared along sprayed and unsprayed crop edges in the same fields. Only along the unsprayed winter wheat crop did the diversity and cover of dicotyledons increase, as did the floristic value of the vegetation. A lot of species were only found on the ditch banks next to the unsprayed cereal edges, such as Ranunculus repens , Thlaspi arvense , Rumex crispus and Papaver rhoeas . Along this crop no effect was found on monocotyledons. No significant effects were found in the ditch-bank vegetation adjacent to the sugar beet or potato crop. This difference in effect on ditch-bank vegetation among the crops can be explained by differences in the spraying method, herbicides used and dosages employed.

Unsprayed field margins: effects on environment, biodiversity and agricultural practice

Abstract A management strategy developed for field margins to reduce pesticide drift to non-target areas and to promote biodiversity on arable land was investigated. It involved not spraying herbicides and pesticides in a strip 3 or 6xa0m wide on the edges of winter wheat, sugar beet and potato crops. This strategy was compared with spraying the edges. The effects on pesticide drift, arable flora, invertebrates, vertebrates, costs and acceptance by the farmer were studied. This article reviews the most important results. Interviews with farmers showed that field margins were sprayed intensively. Drift measurements demonstrated that creating unsprayed buffer zones of 3xa0m width is a very effective way of reducing pesticide drift to the ditches demarcating the field (drift is reduced by about 95%) and risks to aquatic organisms. The presence and abundance of plants associated with arable farming increased substantially in the unsprayed edges, as did the floristic value of the vegetation. The impact on epigeic soil invertebrates was relatively minor. However, there was a pronounced effect on phytophage insects. The number of visits to the unsprayed edges by Motacilla flava flava, an insectivorous bird, also increased. A cost-benefit analysis based on the yield losses showed that it is very feasible to incorporate unsprayed crop edges in the cultivation of winter wheat and potatoes. In sugar beet, however, the cost is too high. However, for reasons to do with agronomy, farming equipment and socio-psychology, farmers will accept unsprayed cereal edges or grass strips but not unsprayed potato edges. From their perspective the most important aspect for acceptance in farming practice is a flexible width of the unsprayed crop edges.

Arable flora in sprayed and unsprayed crop edges

Abstract On 15 conventionally managed arable farms in an intensive arable farming district on marine clay in the Netherlands, edges of winter wheat, sugar beet and potato crops were either sprayed or unsprayed with herbicides and insecticides, during the period 1990–1994. The presence (frequency) and abundance (ground cover) of farmland plant species within sprayed and unsprayed edges and in the sprayed field centre were compared. In all three crops, leaving 3–6 m wide edges unsprayed, both the presence and abundance of farmland plants increased, by factors of 4.8–12.1 and 1.5–2.7, respectively. The effect was greatest in the winter wheat crop. The increase was attributable mainly to dicotyledonous species. Although the majority of the plants were common farmland species, there was a major enhancement of the floristic value of the unsprayed fields. In the sprayed centres of the fields, the presence and abundance of farmland plants as well as the overall floristic value were consistently lower than in the sprayed and unsprayed edges. Leaving the crop edges unsprayed significantly decreased crop cover in sugar beet fields only. If compatibility with farm management is also taken into account, the measures investigated appear to have the greatest potential in winter wheat.

Environmental themes on ecolabels

Abstract A desk study on current market-oriented approaches promoting more sustainable agriculture compared organic farming (EKO), agro-ecolabelling (AMK), ‘environmentally-aware cultivation’ (MBT), Albert Heijn’s controlled cultivation, Sainsbury’s integrated crop management and the TNO label developed for the retailer A&P. The contribution of these to individual Dutch environmental policy themes was analysed. The results of an inventory for arable farming are presented, with special reference to the cultivation of ware potatoes. They show that all the labels include the themes of climate change, acidification, eutrophication and ecotoxicity. The themes of hydrological changes and habitat loss and fragmentation are scarcely taken into account in the Dutch labels. This implies that these labels do not guarantee that sustainable agriculture will be developed. However, the British retailer Sainsbury’s does consider all the six topics explicitly. Although both the environment and biodiversity will benefit from a reduction of pollutant emissions, the labels do not assess the actual effect of the criteria, as there is no analytical framework for transforming the present ecolabels into manageable and effective instruments to achieve sustainable agriculture. Several criteria are proposed for use in market-oriented tools aiming to enhance biodiversity.

Chemical Threat to Birds and Mammals in The Netherlands

This article reviews the impact of xenobiotic substances on wild birds and mammals in The Netherlands, as recorded in the field over the past 25 yr. First, a brief survey is given of population trends during this period, using a few illustrative examples to indicate the role played by environmental policy themes other than diffusion. The present review of the policy theme diffusion is not intended to be exhaustive, but to provide a broad summary of the nature of the problems involved. Based on this review, conclusions are drawn about the ecological compatibility of various groups of xenobiotics with respect to birds and mammals. Because policy-makers are interested in the relative significance of both the various groups of substances and the various environmental themes for the decline of bird and mammal populations in The Netherlands, a provisional estimate of these contributions is also presented. The main conclusion is that, in the context of the policy theme diffusion, PCBs and pesticides have the greatest impact on birds and mammals. PCBs have an impact up to the species level, whereas the main impact of pesticides today is probably ecological, that is, foraging and habitat changes. It is also concluded that the share of the theme diffusion in the sum total of negative environmental influences is approximately one-quarter.

Promoting nature conservation by Dutch farmers : a governance perspective

ABSTRACT Reconciling productive agricultural practices with nature conservation is not only an ecological challenge, but also a demanding matter of governance. This paper analyses the potential as well as the limitations of various governance arrangements, and explores ways to enhance the governance of nature conservation in agricultural landscapes. We assume four conditions to contribute to the performance of these arrangements: farmers should be motivated, demanded, enabled, and legitimized to participate in arrangements that promote nature conservation by farmers. We analyse 10 distinct Dutch governance arrangements in the period 2000–2016, including agri-environment schemes but also privately initiated arrangements. The arrangements target a large but unknown share of farmers and farmlands, but nature conservation ambition levels are generally low to moderate. The expected low-to-moderate performance is associated with a low-to-moderate motivation, demand, and ability. Underlying are stronger forces driving towards intensification and problems farmers face in recuperating the cost of nature conservation. New greening requirements in the EU Common Agricultural Policy and in agri-food supply chains are first, cautious steps addressing these fundamental drivers of ecological degradation. More ambitious greening requirements may contribute to a higher motivation and ability of larger groups of farmers to implement nature conservation measures.

Population responses of Daphnia magna, Chydorus sphaericus and Asellus aquaticus in pesticide contaminated ditches around bulb fields.

The goal of this study was to investigate the effects of ambient concentrations of pesticides combined with abiotic factors on the key aquatic species Daphnia magna, Chydorus sphaericus and Asellus aquaticus by means of 21 days field exposure experiments. In situ bioassays were deployed in ditches around flower bulb fields during spring and autumn 2011-2012. The results showed that phosphate was the most variable parameter followed by pesticides expressed as toxic units, as the main factors explaining differences between sites. Variation in reproduction and growth of cladoceran D.xa0magna was largely explained by nutrients, whereas dissolved oxygen contributed mostly to variations in reproduction of C.xa0sphaericus. Dissolved organic carbon contributed to variations in growth of the detrivore A.xa0aquaticus. It is concluded that abiotic stressors rather than pesticides contributed significantly to the performance of aquatic invertebrates.

Agrarisch natuurbeheer in Nederland: Principes, resultaten en perspectieven

Dit boek geeft het eerste brede overzicht van agrarisch natuurbeheer in Nederland. Naast de actuele stand van zaken schetst het boek perspectieven voor de toekomst die inpasbaar zijn in de bedrijfsvoering. Het bestaat uit drie delen. Het eerste deel gaat in op de ontwikkeling van het natuur- en landbouwbeleid en van de organisaties die zich voor agrarisch natuurbeheer inzetten. Het tweede deel geeft een overzicht van de ecologische aspecten, waarbij naast weidevogels, akkervogels en ganzen, ook sloten, opgaande begroeiing, erven en gebouwen aan bod komen. Ook worden de functies van biodiversiteit voor de landbouw belicht. Het laatste deel van het boek behandelt de inpasbaarheid in de bedrijfsvoering en de betekenis voor verbreding van de landbouw. Het afsluitende hoofdstuk schetst de perspectieven voor natuur in het boerenland. Hierbij worden relaties gelegd met het huidige landelijke, provinciale en Europese beleid. Aan dit boek hebben ruim 40 auteurs meegewerkt, die tezamen een breed spectrum aan disciplines bestrijken. Het is bedoeld voor allen die met agrarisch natuurbeheer te maken hebben of daarin geinteresseerd zijn, zoals agrarische natuurverenigingen en collectieven, natuur- en landschapsbeheerders, boeren, waterschappen, onderwijsinstellingen, recreanten en beleidsmakers.