New trials undertaken by ADAS have shown that preserving cereals by crimping kills 100% of the black-grass seeds ensiled with the crop.
The results come as welcome news to arable and grassland farmers, who may be able to use crimping as a means of reducing the burden of black-grass on their farms. Researchers have speculated this burden could decline year on year, if crimping is undertaken over the long term.
A further benefit of the crimping process – which involves processing and adding a preservative to the grain and ensiling it in a clamp or plastic tube – comes through its early harvest which is typically three weeks ahead of dry cereal harvest.
The trials also demonstrated that at the time of an early harvest, black-grass seeds were less viable (achieving an 18.6% germination rate) than seeds from a fully mature plant (42% germination).
The early harvest associated with the crimping process also increased the amount of black-grass seed removed from the field, compared with conventional harvest timing.
The findings add to a string of benefits to come from crimping rather than harvesting dry cereals. These include the higher nutritional quality of the earlier-harvested cereals, the reduced grain loss through shedding and disease, the ability to start autumn cultivations on the cereal ground earlier and the lack of a need to dry grain.
Dr Laura Davies, ADAS weed researcher, who carried out the trial said crimping looked very promising as an additional method of reducing the black-grass burden on a farm. She said it could be used alongside a range of practices beneficial for reducing black-grass, including strategic ploughing, delayed autumn drilling and opting for spring- instead of autumn-sown cereals.
“We are very encouraged that this trial demonstrated the crimping process itself will kill black-grass seed, making it unviable,” she said. “This suggests that early harvest and crimping could be an effective part of a multifactorial approach to black-grass control.”
Furthermore, she said the results were so promising that their long-term impact over several seasons should be researched.
“We would like to investigate the impact of early harvest on reducing the weed seed bank and emergence of black-grass in subsequent crops,” she said.
Feed preservation specialists, Kelvin Cave Ltd, whose product, Crimpsafe 300, was used in the trials, said the results confirm what they have heard anecdotally for many years.
“Farmers are increasingly using early harvest and crimping as part of their black-grass control strategy,” said Michael Carpenter, the company’s northern area manager.
Neil Welburn who farms 1,600 acres near Goole in Yorkshire is a case in point, and has turned his entire cereal acreage over to crimping.
Mr Welburn says: “Early harvest and crimping are an important part of our black-grass control strategy. We set the combine sieves fully open for crimping and catch all of the weed seed, which you can see in the tank.
“Once everything has been through the crimper, had the preservative applied and been clamped for a month or so, my feeling is that the seed isn’t viable at all.”
He now produces around 500 tonnes/annum of crimped cereals, fattens 600 head of cattle every year on a high crimp ration and sells the remaining 300 tonnes to other livestock producers.
“The cattle are really healthy and the grades have definitely gone up since we’ve been feeding crimp,” he says.
The product is also widely endorsed by independent nutritionists including Stephen Caldwell from SC Nutrition (UK) & Grass Science.
He says crimped cereals are safer for the rumen than dry, rolled cereals or compound feed, and can be fed in higher quantities.
“Crimp wins on several counts for me as the cows perform well on it because it is so rumen-friendly, without any negative action on rumen function and intakes; it’s very straightforward, usually coming straight from another farm in one journey; and because of this, it’s both cost-effective and good for the environment.”
“I think we will see more crimp traded from farm to farm as this low-cost, home-grown feed increases in popularity with livestock producers,” adds Mr Carpenter. “And now we have such compelling evidence of its agronomic benefits in arable rotations, we expect growers will be keen to produce crimped cereals to trade with their livestock farming neighbours.”
Germination of black-grass seed collected at crimped grain harvest, at black-grass seed shedding, and seed stored in crimped grain for one month
Black-grass seed collection timing
% Germination (average across three replicates)
Field collection at time of crimping
One month crimped
June 2017 (+ 1 month crimped)
Initially predominantly in East Anglia but black-grass has spread north and west
The ninth most common weed in 1989, by 2009 it was number one
Around half of the UK’s wheat production area is affected
80% of black-grass populations show resistance to one or more herbicide
Non-herbicide control can include changing cultivations, drilling, competitive crops and preventing seed return
What is crimping
Crimping cereals involves the rolling of early-harvested grain through a crimping machine to expose the carbohydrate and protein, and the application of a preservative. This ensures a controlled fermentation and maximum nutrient retention once stored in an airtight clamp (or plastic tube). A range of modern preservatives allows cereals to be crimped at moisture contents of 25%-40% and maize at 35-40%. Crimp must remain sealed for at least three weeks and can then be fed throughout the year.
Why crimp grain
Maximises nutrient value, digestibility and dry matter/ha
Enables earlier harvest at peak nutritional value
The process is simple – crimp, ensile, feed
No drying or specialist storage is required
Allows early establishment of follow-on crops
Reduces grain loss in the field
Harvest is less weather-dependent
Turns home-grown moist cereals into quality, digestible and palatable concentrate feed
Improves animal performance (dairy, beef or sheep) over dry-rolled cereals
Completely destroys the viability of black-grass seed in the clamp
Backed by over 40 years successful use in Finland and northern Europe