GrainsWest Spring 2021

Spring 2021 grainswest.com 33 JOHN HOLLAND Fordingbridge, Hampshire county, England Farmers in England continually seek new ways to get the edge on pests. In a country where stringent guidelines around certain insecticides exist, pest management is of critical importance. Over the last 30 years, English farmers have taken note of the tremendous role beneficial insects may play in their fields, according to John Holland, head of farmland ecology with the Game and Wildlife Conservation Trust (GWCT). “Insecticides do have an impact on non-target species, which have an important role to play,” he said. “Farmers have come to recognize that. There’s more skepticism with agrochemicals and the reliance on them.” Despite certain farmers’ suspicions around crop protection products, there is still a missing link when it comes to a greater uptick in farmers using beneficials such as lady beetles, ground beetles, spiders, hoverflies, lacewings and parasitic wasps. A 2019 GWCT and Agrii survey of 182 farmers found 90 per cent adhere to integrated pest management (IPM) strategies of which 45 per cent had adopted practices to supply beneficial insects with better natural environments, recognizing their importance in crops. “Lots said they were practicing integrated pest management, but when you drill down to what they’re doing, their interpretation is different,” he said. “That evidence is coming together but farmers aren’t doing it in a comprehensive setting. For IPM to be successful a suite of measures is needed.” And while there are economic threshold guidelines for farmers to refer to, not many hold the recommendations in great esteem. Most English farmers have a hired agronomist employed for one primary reason, to help achieve maximum yield. That approach is fraught with error from Holland’s perspective. “[Agronomists] look after big acreages, they don’t have time to look at every field,” he said. “They take a broader approach, look at one or two fields and apply the same to all the fields. Farmers and agronomists are understandably risk averse with most crops and the uncertainty of IPM compared to pesticides is difficult to overcome.” One method now embraced by increasingly more English farmers is that of a beetle bank. What appears as an unassuming mound of soil is actually a sprawling mansion, ideal for beetles to make a home and overwinter. Farmers seed the banks with a grass mixture and densities inside the banks can quickly reach 1,000 beetles per square metre. They are often utilized to divide large fields. In spring, the beetles leave the banks and fan out in force, but only about 60 to 70 metres from homebase. This is inefficient, but better coverage is achieved when banks are placed throughout the field. The banks additionally prevent soil erosion, impeding the flow of surface water. A bank is often two to three metres wide and can be as long as a farmer wishes to make it. To allow for movement of machinery, particular banks run the entire length of a field but don’t connect to field boundaries. Farmers have also begun to experiment with cover crops and flower strips to attract additional beneficials to their fields. Anecdotally, results show promise as these methods do help draw insects. With the recent neonicotinoid ban on oilseed rape, however, farmers are shifting away from the crop, which has limited rotational alternatives, primarily faba beans, peas and flaxseed. Neonics, “the perfect solution,” handled flea beetles, the common predator of oilseed rape, Holland explained. “Before, you have one neonic seed dressing. Now, you have two to three broad spectrum foliar applications.” Holland suggested there is more work to be done to educate farmers about IPM techniques. Seemingly insignificant, this long strip of soil is a beetle bank, the home of countless ground beetles that roam farm fields to attack pests. Photo:Courtesyof JohnHolland