While the use of synthetic pesticides in agriculture might have helped to increase food production, this has not occurred without great costs to human health, the environment and natural resources. The 2017 UN report of the Special Rapporteur on the right to food highlights the adverse impact of pesticide use on human rights, human health (workers, their families, bystanders, residents and consumers) and the environment. The report also reveals that intensive agriculture based on pesticide use has not contributed to reduce world hunger, but rather it has helped to increase the consumption of food and food waste especially in industrialised countries.
Herbicides have been introduced in agriculture (and horticulture) mainly to combat weeds that compete with crops for nutrients and sunlight resulting in reduced crop yield and quality. Other common uses are to eradicate invasive plant species or undesirable plants for livestock farms, to assist the management of public areas, for aesthetic or practical reasons (e.g. sidewalks, pavements and railways) or for weed control in private gardens. In Europe, their use in farming has increased considerably to replace mechanical ploughing, which has been reported to cause soil degradation and soil nutrient loss, in certain geographic zones with high rainfall and specific types of crops, particularly in intensive agriculture (Derpsch, 1998).
There is an overall erroneous perception that herbicides are safe for human health and have little impact on the environment. Based on this misconception, humans have developed agricultural practices and invested in technological development that completely depends on the use of pesticides and herbicides. Many farmers have abandoned more sustainable farming techniques altogether. As a result, every day tonnes of herbicides are released into the environment and their surroundings, which not only put human health at risk, but also interfere with the biological processes of nature and the ecosystem services it offers to combat weeds and other pests naturally. Weeds become resistant, the soil get eroded and infertile, the crop susceptible to pathogens and diseases, and farmers feel obliged to use more pesticides to combat the new pests, and end up trapped in a “pesticide treadmill”.
In a similar manner to other pesticides, herbicide active ingredients are biologically active compounds. They are designed to pass through membranes and diffuse into the interior of living cells to exert the desirable toxic action (Kearney & Kaufman, 1975). Because of their properties, when these substances are used on open fields they will directly affect other non-target species in the area and the surroundings, and through a cascade of ecological interactions will end up affecting biodiversity. Furthermore, these same properties may allow them to interact with living cells of animal species including humans and result in toxicity. Herbicides can also be toxic to soil beneficial microorganisms (Grossbard & Davies, 1976) causing a decline in soil nutrients, fertility and defence systems. This has a direct impact on agriculture, where crops depend on the quality of the soil.
Their use has been so -unnecessarily- intensive that these chemicals have caused a great impact not only on soil health and agricultural production, but also to human health, the environment and its ecosystems. The present report aims to emphasise that we already have all the tools necessary to gradually start building a pesticide-free agricultural model and to confirm that weed control is possible using other means than harmful herbicides. There is an urgent need to develop technological methods of agriculture that do not depend on pesticide use. Using the popular glyphosate-based herbicides as a reference, the current analysis presents a wide variety of weed management approaches, where farmers work together – rather than against – nature and help maintain a high agricultural yield without contaminating the soil, destroying biodiversity and jeopardising human and environmental health. Since glyphosate-based herbicides are non-selective and of broad spectrum, the alternative methods presented in this report can also substitute the use of different herbicide products.
This report also covers topics such as the use of glyphosate in the EU and globally, pesticide sales in the EU, and impacts on soil behaviour and environmental safety, as well as human health.
By integrating the different available agricultural practices (e.g. preventive, agronomic and mechanical methods) with the broad knowledge we have acquired on the biological and ecological characteristics of herbs and plant crops, today farmers are capable of overcoming major agricultural challenges and manage weed growth successfully, maintaining a high agricultural yield, avoiding resistant species, protecting soil biodiversity and erosion, and reducing green-house emissions among others. This report presents and discusses the different alternative agricultural practices to herbicide use in weed control that when combined result in a sustainable weed management. This work was carried out in parallel with the project “Filming farmers across European Union on alternatives to herbicides (with specific reference to glyphosate)”, both being supported by The Greens/EFA of the EU.