Page 49 - ALG Issue 2 2021

Herbicide contamination at Chinley Allotments
Our small, but perfectly formed Derbyshire allotment site sits at the very edge of the Peak District. The spring of last year produced strange and worrying developments. Young plants developed grotesquely twisted and feathery growth. Some stopped growing. Others died. Beans, tomatoes, peas and potatoes seemed to suffer the most. Aminopyralid herbicide contamination was suspected.
CHINLEY ALLOTMENT SITE
Aminopyralids and clopyralids
are present in previously banned commercial herbicides marketed by the Corteva subsidiary of Dow Agriscience. Products containing these chemicals are used on grassland to control broad- leaved ‘weeds’ and promote grass growth. Typically, the grass is then
cut, stored and fed to livestock. These herbicides can pass unscathed through the livestock. If the animal dung is used to fertilise the ground for growing crops, contamination occurs. This can persist in the soil for up 12 months before breaking down, effectively poisoning the area for this time.
At Chinley Allotments we compost horse manure from local stables in two large communal hoppers. The stables purchase hay from a large dealer, who in turn buys hay from many different sources. It would appear that this is the route of our contamination. Tracing the exact source of the contamination is incredibly difficult.
Corteva were contacted and took
soil samples in June 2020. Despite increasing pressure from us, the samples were not tested until January 2021, when we received confirmation of what we had suspected. High levels of herbicide contamination were present in the animal-based compost we were using. The surprise was that it was a clopyralid herbicide, not aminopyralid. However, the compounds are from
the same picolinic acid family, both produced by Corteva Agriscience and have the same uses. Both also persist in the soil.
We have been offered a ‘without prejudice’ cash settlement which we have refused. We asked Corteva to
conduct further tests, but they have refused to do so. Some of our members feel that Corteva are not taking the problem seriously.
Clopyralid (3,6-dichloro-2- pyridinecarboxylic acid) is a selective herbicide used for control of broadleaf weeds, especially thistles and clovers.
It is especially effective at controlling creeping thistle. Like other similar herbicides, it is particularly damaging to peas, tomatoes, sunflowers, potatoes, lettuce and spinach. Clopyralids are banned in some areas of the world, but not in the UK.
The very similar aminopyralid herbicides were withdrawn in the UK
in 2008 following serious concerns. However, they were reintroduced in late 2009 ‘with new recommendations and a stringent stewardship programme devised to prevent inadvertent movement of manure from farms’. Farmers who sell aminopyralid treated grass products are meant to provide documentation to the buyer advising them of the treatment and safe waste disposal. It is unclear if clopyralids are subject to the same controls.
Following local publicity about the contamination of our site, a Corteva
This much is clear to us: these herbicides are a poison which kill many of the plants and vegetables we all want to grow
Agriscience spokesman said: “We
are revising and strengthening the instructions for use for clopyralid- containing herbicides to minimise further any future occurrence as it is important that gardeners and growers can enjoy the benefits of using manure with confidence.”
This much is clear to us: these herbicides are a poison which kill many of the plants and vegetables we all want to grow. These poisons are finding a way into our composts, our allotments, our gardens and our food. The controls put in place do not appear to be fit for purpose. Our site was contaminated without our knowledge and with frightening ease. Perhaps the time
has come to withdraw this family of herbicides, before more of our gardens and allotments are poisoned.
Stephen Minter, Chair of Chinley Allotments Association steve@minter.xyz
Image credit: Steph Hafferty at https:// nodighome.com/about/
Allotment and Leisure Gardener 49