Combatting blackgrass: Do we need a different approach?

With its ability for rapid population increase and to develop resistance to herbicides, blackgrass has become a major headache for many UK farmers.

Blackgrass populations can increase 10 times annually, with some research indicating that even larger growth is possible.

This means farmers face the challenge of having to control over 95% of blackgrass each year to prevent a build-up.

Using herbicides alone to combat blackgrass is having increasingly limited effect due to its ability to build resistance. So, do we need a different approach?

Using regenerative practices to reduce blackgrass

Regenerate Outcomes soil consultant and mentor Kyle Richardville says it is clear that blackgrass management requires a long-term strategy in which a farmer may use multiple agronomic, cultural and herbicidal approaches.

However, a key consideration is to focus on soil health.

Blackgrass is found on both heavy and light soil but is known to thrive on heavy, poorly drained soil.

Kyle says tackling the problem requires a shift in mindset from applying external inputs to working with nature and diversity to improve the soil.

“One reason why blackgrass thrives in this environment is that the plant is able to diffuse oxygen from the shoots to the roots through a straw-like structure called an aerenchyma,” says Kyle.

                                                Kyle Richardville

“This is their competitive advantage, along with their ability to produce up to 2,000 seeds per plant in a hurry.

“The farmer should take this information and begin formulating a long-term plan to create an unfavourable environment for blackgrass. Such a system is one where a soil can infiltrate, hold and percolate water efficiently.

“In other words, farmers can mitigate blackgrass risk by implementing management practices that lead to improvements in soil aggregation and soil organic matter because both factors heavily influence proper water cycling.”

Understanding the role of weeds in soil health

Kyle says the presence of blackgrass - and indeed many weeds - is a sign of a system in which certain well-adapted pioneer species are thriving by taking advantage of a depleted soil.

It is possible for farmers to change these circumstances and begin to reduce weeds through management which encourages more diversity above and below ground.

“All life on the planet should be viewed as overwhelmingly collaborative, not overwhelmingly competitive,” says Kyle.

“Farmers that make the most regenerative progress begin to view ‘weeds’, ‘pathogens’ and ‘pests’, as simply organisms doing a job for everyone else.

“In the case of weeds, plants like blackgrass are photosynthesizing and feeding a compacted soil so that the system can support a diversity of life one day.

“Does this mean we should let blackgrass or brome or wild oats overrun a field? Of course not. We’ve still got a business to run. But the fact is that they are doing a job, and we can learn a lot from them if we pay attention.

“Landscapes and organisms function best when they are filled with an abundant diversity of life with populations that are constantly ebbing and flowing. This prevents one or two species from dominating.

Prevention is better than cure

“The regenerative approach to managing weeds (and pathogens and pests) can be summarised quite succinctly in the phrase ‘an ounce of prevention is worth more than a pound of cure’,” says Kyle.

“The most successful farmers we work with focus on implementing management practices that build soil health by promoting life above and below ground.

“Healthy soil promotes more life and now the system is undergoing a virtuous upward spiral that prevents a problem from happening in the first place.

“As a result, the amount of money they spend on fungicides, herbicides and fertiliser reduces because the biological system is healthy enough to provide those services and prevent the takeover by a microbe, insect or undesirable plant.

“Agriculture’s reliance on chemicals and tillage to control weeds is the very definition of madness. We’ve been trying the same thing over and over again and expect a different result.

“Yes, herbicides, planting timing and tillage are effective tools in the toolbox to help manage blackgrass in the short-term, but long-term, sustainable success comes from understanding their role in the ecosystem and using their strengths to your advantage.

“The real challenge is how to manage problems in the short-term while building up the system in the long-term. It takes a long-term, systems approach to prevent blackgrass domination in your specific context.”

Learn more about how soil health can help reduce blackgrass

Kyle will be leading our webinar Combatting blackgrass: Do we need a different approach? on 16 October 2024 (7pm until 8pm)

In the webinar he will delve deeper into tackling blackgrass through improved soil health.

Kyle will be joined by Ian Gould, Director of Oakbank Game and Conservation and farmers George Hosier and John Charity.

George and John are part of the Regenerate Outcomes programme and will share the highs and lows of controlling blackgrass on their farms.

There will be time for Q&A at the end of the presentations to ask your questions.