Sustainable use of glyphosate in Conservation Agriculture

Abstract

About 95% of the food is produced directly or indirectly from soils, so achieving healthy soils is crucial for food security. Unfortunately, many threats pressure soil to be degraded, and tillage-based agriculture compromises the sustainability of agriculture, and therefore of safe food production. It is well known that Conservation Agriculture protects and improves soil health, but to achieve the success of the system farmers need to face some challenges, and one of these is how to address weed management. The adoption of the three principles of Conservation Agriculture (CA) is essential to introduce integrated weed management in farms. All three principles of CA help to reduce weed infestation density and pressure. But, the application of herbicides is a useful complementary tool necessary to and ensure crops profitability. In CA, the most used herbicide in integrated weed management strategies is glyphosate. CA facilitates the safe and minimum application of glyphosate per hectare. Therefore, glyphosate is the most widely used herbicide in CA. However, the use of glyphosate is plenty controversial. It has been declared by the European Food Safety Authority (EFSA) as potentially carcinogenic. In contrast, studies carried out by the United States Environmental Protection Agency (EPA) ensures that there are no risks to human health when glyphosate is used according to the specifications of the label. To understand more reliably the use of herbicides and specifically the use of glyphosate in European agriculture, the European Conservation Agriculture (ECAF), in collaboration with its National Associations, launched a survey in 2020. This survey asked farmers about soil management, use of herbicides and alternatives in case of herbicides ban. In all, 1677 responses were received from 21 European countries. According to the results obtained, it can be observed that glyphosate is the most commonly used herbicide in European agriculture with 88% of the responses, independently of the soil management system: No-till, minimum tillage or conventional tillage, being mainly used for the control of weeds in preemergence. Likewise, no differences have been shown between the doses of use between conventional agriculture and No-till, overturning the belief that techniques included on CA use more glyphosate to control weeds in preemergence. Also, and asking about the perception of the effectiveness of this herbicide, more than 80% of the farmers surveyed think that glyphosate offers good weed control. Finally, the results show that in case of glyphosate will be banned, farmers do not find any viable and profitable alternative. In addition, if finally, the renewal of use of glyphosate won´t be approved in Europe, a large number of farmers who manage their crops under CA would return to tillage, with the negative consequences that it would have concerned soil health and GGH emission. Therefore, integrated weed management, including the adoption of the three principles of CA, along with judicious use of glyphosate, helps improve the environment compared to tillage-based agriculture.