A new study published in Frontiers in Sustainable Food Systems has found beer waste can provide a sustainable alternative to (often harmful) pesticides.
The research team from NEIKER-BRTA Basque Institute for Agricultural Research and Development in Spain have been investigating the application of bagasse (used beer grains) and canola (rapeseed oil) in combination with cow manure to create an organic pesticide.
“Rapeseed cake and beer bagasse are two potential organic treatments which have shown really positive results in previous studies,” says lead researcher Maite Gandariasbeitia.
“Their high nitrogen content promotes the activity of beneficial microorganisms in the soil, which helps to break down organic matter like manure and kill off nematodes and other parasites which damage crops.”
A trial deploying this mixture into soil in a lettuce patch was conducted, taking place over 7 weeks in a commercial greenhouse. The findings showed that microbiological activity increased in the treated soils and instances of plant parasites decreased. In particular, nematodes were targeted – a crop-destroying pest that infiltrates through the roots. Previously, the same greenhouse had lost up to 45% of its crop yield due to nematodes.
While bagasse is taken from beer production residue, canola cake is a by-product of oil extraction. The former has no typical commercial value, while the latter is commonly used as livestock feed for its high protein content. Both contain high levels of nitrogen and hydrogen – elements that help to boost microbe activity and break down organic matter.
Although the results are promising, the team’s research is not yet over.
“There are still many questions to answer so that we can gain a better understanding of what happens in the soil during and after these biodisinfestation treatments,” says Gandariasbeitia.
While traditional pesticides are efficient in boosting crop yields, the market for an organic alternative has opened up due to concerns over the ecological impact of these chemical-rich fertilisers. A new study found that over the last 25 years, the toxicity of over 300 pesticides in use in the US more than doubled for insects such as mayflies and dragonflies.
Research such as that conducted by Gandariasbeitia’s team opens the door for other renewable, biomass-based solutions.
