This publication is meant as a background document to support the debate that will take place during the workshop ‘Farming without plant protection products?’, 6 March 2019, which contrasts the contents of this report with perspectives from conventional agriculture, the stance of organic farmers and the viewpoint of consumers.
Can we grow without using herbicides, fungicides and insecticides?
Food security and healthy food for 11 billion people by 2100 is one of the biggest challenges of this century. It is one of the most important, if not the most important, human rights, and any agricultural system has to fulfil this requirement within the planetary sustainability boundaries. This implies that no further land increase for agriculture is acceptable, since this is the most important driver for biodiversity loss, greenhouse gas increase and environmental impact. According to scientific literature, there is no other option than to increase the global yield efficiency and reduce the yield gap to guarantee global food security. As such, one can ask the question if it is possible to maintain current yields in north-west Europe and increase yields in other regions of the world without plant protection products (PPPs) or with reduced PPP use. But how can we deal with the public perception that PPPs are unhealthy, with very negative impacts on biodiversity and environment?
PPPs include herbicides, fungicides and insecticides. PPPs can be synthetic PPPs or natural PPPs (‘biopesticides’), used in organic agriculture. The amount of PPPs used has doubled since 1980 but the development of new conventional (synthetic) PPPs has decreased, partly because of legislation issues, while the number of biopesticides has increased in the last decades. The increased use of PPPs was one of the drivers of the ‘green revolution’, and contributed to the 2.5-times increase of crop yields in developed countries. Looking at the EU countries, there are considerable differences in PPP use and this correlates with differences in crop yield. The shift from broadly acting PPPs to more specific PPPs, that only target specific pests or diseases and avoid impact on non-target organisms, implies that farmers have to spray more with these specific acting PPPs. This is the most important reason for the recent increase in PPP use, without the positive effect on crop yield increase of the past.
The introduction of PPPs in the EU is very strictly regulated and involves a long procedure, including a science-based risk assessment. This includes an evaluation of the toxic effects on humans and other organisms. PPPs are today, when applied properly, much safer than in the past and there is a strict control on residues. A safety factor of 100 ensures a much lower risk level than other daily risks to which humans are exposed. Also the application technology of PPPs has improved considerably, which contributes to lower impacts on the environment and risks for applicants. Risk assessment costs for the crop protection industry per active substance increased from US$41 million in 1995 to US$71 million nowadays.
Crop protection not only entails the use of PPPs but also other alternative measures, such as crop rotation, the implementation of resistant cultivars (not at all or less available in many crops), soil management and others. Without PPPs, yields will be reduced, depending on the crop, and reductions of between 19 % (wheat) and 42 % (potato) have been reported. These reductions are higher in regions with high actual production, the latter also as a result of the input of fertilizers, high-yielding varieties, irrigation, etc. Without PPPs, including biopesticides, the food security of 11 billion people in the future is threatened. On the other hand, it is still an open question whether it is possible to reduce the use of PPPs without yield reduction. There are several indications that, for specific crops, a reduction in PPP use is feasible. The general tendency is that a reduction seems possible in the case of (very) high actual PPP use, but not in the case of low use.
PPPs still have unwanted and unavoidable side effects, such as their negative impact on biodiversity. However, this correlation is not always well-studied and it seems that the most important effect on biodiversity (loss) is due to land use changes. In this respect it is clear that organic farming, and its implementation in agro-ecology, is often not the best choice. At farm level, all scientific meta-studies indicate that the increase in biodiversity is rather marginal, but that, at global level, there will be a drastic decrease in biodiversity, since organic farming is approximately 25 % less productive than conventional farming. This implies that, to feed 11 billion people, more land is needed at the expense of biodiversity. Moreover, the perception that natural PPPs, used in organic farming, are less toxic and lead to less residues is not always correct and needs further scientific confirmation.
Although there has been a lot of progress in the past concerning the impact of PPPs on humans and environment, considerable improvements are still possible. Reduction of PPP use seems one way, e.g. based on sophisticated warning and decision support systems, but such reduction is only realistic when the risk of yield or food quality reduction is acceptable for the farmer. Precision farming, including remote sensing with unmanned aerial vehicles, can also contribute to more targeted application and reduction of PPP use. An important contribution will also come from the breeding of more resistant varieties, both by classical breeding and by new breeding techniques, such as precision mutation breeding using the CRISPR-Cas approach or by genetic transformation. The latter techniques will be unavoidable to reach the SDGs concerning food security, and healthy foods with respect to the planetary sustainability boundaries.
Read the complete In-depth Analysis on ‘Farming without plant protection products‘ in the Think Tank pages of the European Parliament.