What lessons can we learn from the European glyphosate review?
OPINION: Glyphosate use in Europe has resulted in reassessments, reviews and bans in some countries, causing a backlash by farmers.
The controversial herbicide is touted by NZ Professor of Toxicology Ian Shaw as a victim of its own success. It’s successful because it is the most widely used herbicide in the world, it is versatile, and its use can benefit the environment. Conversely, its use has ignited heated debate around the globe, with many having their own slant on its safety - often resulting from conflicting reports and limited understanding of the science behind its use.
As the renewal of the EU authorisation of glyphosate looms, European farmers fear that a ban on glyphosate would see their crops taken over by deep-rooted weeds and suffer quality losses, alongside a reduction in farm productivity. Environmentalists are concerned about an increase in carbon emissions and a detriment to soil health and erosion.
The prospect of a ban on glyphosate is placing enormous pressure on European farmers.
They would face substantial weed pressure - as weeds compete with crops for light, water and nutrients.
An even greater pressure exists with climate change and the need for farming practices to become more sustainable. Taking this vital tool away from farmers would lead to more mechanical weeding, more time spent ploughing, and more money spent on fuel alongside the environmental impacts.
Farmers concede that minimal glyphosate use is possible, but an outright ban will be catastrophic because it would entail more tillage to manage weeds leading to soil degradation. If glyphosate is not available, farmers would need to use three to four other herbicides in its place, leading to more tillage and more resources to manage weeds. The other complication and contradiction to current environmental goals is the contribution that tillage makes to climate change.
Plants absorb carbon dioxide from the atmosphere through photosynthesis and pass carbon to the ground when dead roots and leaves decompose. Tillage releases this carbon from the soil to the atmosphere, contributing to global warming.
Tillage fractures the soil, disrupting soil structure, accelerating surface runoff and soil erosion. It also reduces crop residue, which helps cushion the force of pounding raindrops. Without crop residue, soil particles become more easily dislodged, being moved or 'splashed' away.
Soil degradation starts after rainfall, with run off entering nearby streams, gullies and rivers. The sediment in the water turns it brown and is eventually released into the sea, affecting sea life. Soil degradation from erosion is very expensive for Europeans, costing up to 14 billion euros annually.
According to the Secretary General of the European Conservation Agriculture Federation at the University of Cordoba, Dr Emilio Gonza´ lez, creating 1cm of soil takes between 100 to 200 years. So conserving soil, he says, is vital for the conservation of the environment.
To rehabilitate soil, a system of conservation agriculture supported by the Food and Agriculture Organisation and practised in many regions of the world - is necessary. Conservation agriculture improves
The prospect of a ban on glyphosate is placing enormous pressure on European farmers.
productivity and ecosystems and protects water and soil. It’s based on the three principles of minimum soil disturbance (no tillage), permanent soil cover or crop cover, and species diversity ie crop rotations.
No till is a prominent aspect of conservation agriculture due to intensive tillage practices destroying soil structure. Instead of ploughing the soil, farmers can modify and adapt to the conditions with new machinery and by using herbicides to control weeds. The system is working in many European countries, with four million hectares of no tillage and permanent crops.
It improves soil fertility and optimises outputs and productivity - a win-win for farmers and the environment. Minimum tillage practices increase carbon sequestration in soil and reduce greenhouse gas emissions through decreased use of fossil fuels in field preparation.
Crop rotation and diversification are recommended for achieving agriculture conservation, together with good soil cover to prevent weeds from emerging. Herbicides should then be applied when needed. Monoculture presents more weed problems and entails higher doses of herbicides, which could lead to resistance.
Glyphosate for weed control reduces other inputs and improves soil health and structure. It can tackle tough weeds in one spray after harvesting and, ideally, in combination with cover crops to help manage weeds. Farmers can apply glyphosate with fertiliser, seeds and cover crop in one go - saving time and money. They still need to check for weeds and then apply herbicides for the specific weed issue - at the correct dosage, following label instructions. The emergence of smart agriculture technology, precision agriculture and drones for applying pesticides, will help farmers to identify and manage weeds in the most efficient way.
Farmers need the best tools and technological solutions to grow enough crops - using fewer natural resources to produce sufficient high-quality food, respect the environment, safeguard consumers and support themselves. Allowing them to use the right tools at the right time for the right crops will assist them do this.
Helping farmers build a stronger and more resilient agricultural economy, requires an open and transparent dialogue and collaboration between scientists, academia, innovators, politicians, regulators, NGOs and all along the food value chain from farmers to consumers.
• Mark Ross is chief executive of Agcarm, the industry association for companies which manufacture and distribute crop protection and animal health products.
• For expert science opinion on New Zealand’s review of glyphosate, see: https://www.sciencemediacentre.co.nz/ 2021/04/28/input-on-glyphosate-soughtexpert-reaction/
• For more information on the safety of glyphosate, see:
http://agcarm.co.nz/glyphosate/