This article was written by fifth-former Janek Czarnek, and provides a shortened abstract of his original essay titled: “The Use of Pesticides: Beneficial or Detrimental”. To view his complete article, click the link at the end.
Estimated read time: 4 minutes
The Uses and Consequences of Pesticides and the Viability of Alternatives
It is clear that pest protection is key to agricultural sustainability globally, which is now more important than ever, as with a rapidly growing human population the demand for food is only becoming greater. It is estimated that between 26% and 40% of the world’s crop yield is lost each year due to pests, and this could rise up to 52% to 80% without the use of crop protection (1). Pesticides are chemical compounds used to kill pests, which can include any destructive organism that is a vector of disease or attacks crops or livestock. Not only are pesticides effective, at least in some circumstances, at directly eliminating the threat of pests, but they can also have secondary benefits such as preserving soil quality (1). However, although pesticides may be effective in some circumstances, their true long-term effectiveness and the consequences that they impose on non-target plants and animals pose an important question about their suitability for continued usage. Pesticides can have devastating consequences on non-target organisms and biodiversity, especially on fish where upon entering water sources can kill many fish through acute poisoning or oxygen depletion (2). Considering these effects on biodiversity, alongside increasing resistance to pesticides due to their great usage, are pesticides an effective long-term solution? Are they beneficial or detrimental to us, humans, and non-target plants and animals?
Although there are many consequences to pesticide usage, one cannot forget the crucial role they play in crop protection that serves benefits both for food and biofuel production, as well as in disease control and infrastructure maintenance. A full evaluation of how pesticide usage should change in the coming years must consider how their impacts can be mitigated and whether there are viable alternatives that can effectively protect crops on the scale needed.
Firstly, it is important to note that in some cases the consequences of pesticide usage can largely be mitigated through more careful, and even more regulated, application of these chemicals in a way that is less impactful on the surrounding ecosystems and organisms in addition to those who apply them. Mitigations of the consequences of pesticide use can include simply reading and following labels more closely (3), or using pesticides that do not leach and using more direct application rather than spray application to reduce pesticide drift and subsequently reducing the effects on surrounding ecosystems (3). Farmers can also be advised to leave a ‘buffer zone’ of crops around the edges of fields and agricultural land where pesticides have been used in order to reduce the chance of non-target plants and animals coming into contact with the pesticides (3). Responsible pesticide application can also include taking into consideration the surrounding geography as well as the weather; pesticides should be applied in dry conditions where rainfall is not forecasted because this prevents leaching and surface-run off water carrying the pesticide chemicals away and potentially affecting non target organisms (4). Similarly, pesticides should be avoided where the temperatures are high and when plants are suffering drought as this will increase the rate of transpiration where pesticides can dissolve into water and be dispersed (4). Many other precautions can also be taken; however, it is important to realise that many of the damaging consequences of pesticides can be reduced by taking actions considerate of the surroundings and using them responsibly.
On the other hand, safer alternatives that can still effectively protect crops are always preferable. Many of these alternatives come under the branch of organic integrated pest management, which includes several methods to control pests in an environmentally sustainable manner (5). An important part of this is effectively preventing pest populations growing in large numbers through methods such as companion planting, where plants that repel certain insects are planted, and biological control, where natural predators are introduced to organically control pest populations (6). An example of introducing natural predators is that of utilising ladybird larvae which are effective at managing aphid populations (6) or other symbiotic relationships such as that of fish in rice fields where fish will eat the pests attracted to the rice (7). In Bangladesh it was observed that pest infestation in rice fields containing only rice were 40-167% higher than those that also contained fish (7). Preventive measures can also be combined with increased monitoring of pests and mechanical pest control through means such as fences and nets to reduce access of pests to crops. Alternative chemical means to protect crops have been developed through genetic modification; for example, the genomes of maize and cotton have been altered to include genes that make the plant toxic to pests and hence protect themselves and the surrounding crops (8). All these methods can greatly reduce the impact that pesticides have on biodiversity, the recent Global Biodiversity Outlook 5 indicated that none of the 20 Aichi Biodiversity targets had been reached in the last decade (9) and the Living Planet Report 2020 has said that between 1970 and 2016 there has been a 68% decrease globally in populations of mammals, amphibians, birds and reptiles on average (10); this is up from 60% in 2018 when looking at the period 1970 to 2014 (11). Considering these many alternatives to protect crops from damage from pests, and the need now more than ever to do everything we can to stop reducing global biodiversity, it seems clear that action should be taken to increase the usage of these alternatives that greatly reduce the impact on non-target organisms.
Therefore, in conclusion, pesticides used for agricultural crop protection and other uses with exposure to the surrounding environment are detrimental and have far reaching consequences throughout ecosystems, on both plants and animals, as well as for ourselves. Although pesticides also have important benefits, these will become less effective in the future and can be replaced by alternatives that pose significantly less danger to us and non-target organisms. Moving forward we must ensure that the transition to these safer alternatives is carefully managed, so that they do not affect the availability of food and ensure that they can be provided on the necessary scale. Although this transition may take time, it is clear that pesticides do not have a place in our long-term solution for crop protection from pests and are overall more detrimental than beneficial.
To view Janek’s full article, follow this link below.
1. OECD/FAO (2012). OECD-FAO Agricultural Outlook 2012-2021. Paris : OECD Publishing and FAO, 2012. https://doi.org/10.1787/agr_outlook-2012-en..
2. Fishel, Frederick M. Pesticide Effects on Nontarget Organisms. EDIS University of Florida IFAS Extension. [Online] [Cited: 7 October 2019.] https://edis.ifas.ufl.edu/pi122.
3. United States Environmental Protection Agency (EPA). Tips for Reducing Pesticide Impacts on Wildlife. EPA.gov. [Online] [Cited: 9 July 2020.] https://www.epa.gov/safepestcontrol/tips-reducing-pesticide-impacts-wildlife.
4. The Royal Horticultural Society (RHC). Chemicals: using them in gardens. RHS.org.uk. [Online] [Cited: 9 July 2020.] https://www.rhs.org.uk/advice/profile?pid=817.
5. United States Environmental Protection Agency (EPA). Integrated Pest Management (IPM) Principles. EPA.gov. [Online] [Cited: 9 July 2020.] https://www.epa.gov/safepestcontrol/integrated-pest-management-ipm-principles.
6. Spence, Steven. Gardening Alternatives to Pesticides. Science Connected Magazine. [Online] 2017. [Cited: 9 July 2020.] https://magazine.scienceconnected.org/2017/07/gardening-alternatives-pesticides/#:~:text=%E2%80%9CSoft%E2%80%9D%20chemicals%3A%20soap%2C,pest%20infestations%20in%20short%20order..
7. Halwart, M. and M.V., Gupta (eds.). Culture of Rice in Fish Fields. s.l. : FAO and The WorldFish Center, 2004. [Cited: 9 July 2020.] http://www.fao.org/3/a-a0823e.pdf.
8. GeneWatch UK. Pest Resistent Crops. genewatch.org. [Online] [Cited: 9 July 2020.] http://www.genewatch.org/sub-568238#:~:text=Pest%20resistant%20crops-,Pest%20resistant%20crops,bacterial%20species%20called%20Bacillus%20thuringiensis..
9. Secretariat of the Convention on Biological Diversity. Global Biodiversity Outlook 5. Montreal : s.n., 2020.
10. WWF. Living Planet Report 2020 – Bending the curve of biodiversity loss. Gland, Switzerland : s.n., 2020.
11. WWF. Living Planet Report – 2018: Aiming Higher. Gland : s.n., 2018.
Table of Figures
Figure 1 Rice-Fish Culture in China, FAO, http://www.fao.org/giahs/giahsaroundtheworld/designated-sites/asia-and-the-pacific/rice-fish-culture/en/ 2