Researchers in Bolivia recommend reining in pesticides

Gaby Allheilig, Johanna Jacobi

The year 2005 was pivotal for Bolivian soya production: In that year, the government approved the cultivation of transgenic soya. Since then, the area used for growing the legume has continually expanded, from 94,107 hectares in 2005 to over 1.3 million hectares in 2016. The annual yield per hectare has increased as well – from 1.8 tonnes to 2.3 tonnes, or by about one fourth.

Pesticide use has quadrupled since the authorization of genetically modified soya

While soya production has grown, so too have imports and application of pesticides – i.e. herbicides, fungicides, and insecticides. According to a study conducted in the research project “Towards Food Sustainability” (see box below), pesticide use quadrupled from 10,000 to 40,000 tonnes annually. The study highlights the link between authorization of transgenic soya in Bolivia and massive growth of pesticide imports.

Transgenic soya replaces meat and bone meal in European feed troughs

A total of 229 plant protection products have been approved for use in Bolivia. Of these, 75 are not authorized in the European Union. Yet Europe imported 27 million tonnes of South America’s largely transgenic soya in 2017 – including Bolivian soya. Indeed, Europe is the second-largest buyer after China. One of the reasons for this is that the European Union banned the use of meat and bone meal in (productive) livestock feed following the BSE scandal. Since then, farmers have been feeding their animals the protein-rich pulse instead.

Weeds increasingly becoming resistant

In terms of herbicides, soya producers treat their plantations mainly with glyphosate, which genetically modified soya is resistant to. But several weeds have also developed resistance to glyphosate – and to other herbicides. In the American Midwest, for example, glyphosate resistance affects up to 75% of fields, as reported by the University of Illinois in 2016.

Soya producers are switching to other active substances

In response to increasing glyphosate resistance, many soya producers in North and South America have switched to glufosinate and 2,4-dichlorophenoxyacetic acid – called “2,4-D” for short. European countries are increasingly restricting the use of glufosinate, since it can affect reproduction. And 2,4-D was an ingredient in Agent Orange, used by the US Army to defoliate forests during the wars in Vietnam and Laos.

Another controversial chemical is paraquat. This herbicide – also known as Gramoxone, the commercial name used by its main producer Syngenta – is regularly applied to fields in around 100 countries worldwide, including the USA and Canada. Switzerland refused to authorize this agent back in 1989, for toxicological and ecotoxicological reasons. The EU followed suit in 2007. Even Bolivia’s neighbour Brazil decided in 2017 to phase out use of paraquat over three years.

A combined dose of paraquat and glyphosate

But things are different in Bolivia. Here, paraquat, glyphosate, 2,4-D, clethodim, and atrazine – another herbicide that is banned in the European Union and Switzerland – are among the most frequently used weedkillers in soya production. In order to eliminate as many weeds as possible, producers often spray paraquat and glyphosate together.

According to researchers involved in the CDE project, a single spraying operation in Bolivia’s soya belt may include up to 17 different products. This includes insecticides like methamidophos – a highly toxic compound that is technically banned in Bolivia, but is repeatedly detected in shops and on fields.

Frequent applications

The toxicity of active substances is one thing. The other issue is the quantity and frequency with which they are applied. Investigations in the project “Towards Food Sustainability” showed that Bolivian soya producers apply pesticides up to 12 times per crop cycle – not counting the treatment of seeds.

Reuse of empty pesticide containers for food storage

In Bolivia and similar countries, the dangers of pesticides are often compounded by lack of knowledge among rural populations. Most people are not fully aware of the risks posed by pesticides or the precautions necessary to handle them safely. “We frequently saw people mixing and applying pesticides without wearing protective clothing,” observed Roberto Bascopé. In addition, farming families often live in a single room, where they sleep, eat – and store their pesticides. Many of them reuse empty pesticide containers to store water and food.

Researchers recommend that the government take action

Based on their findings, the scientists have recently recommended a series of measures to the Bolivian government to counteract the worst problems. The recommended measures range from banning various pesticides and curbing illegal trade to promoting eco-friendly farming and educating and informing the population about pesticide risks.