Groundswell is an innovative, farmer-led annual event that showcases farming practices that promote soil health, for example by not ploughing and the introduction of mob-grazed cattle.
Hundreds of farmers attended the inaugural ‘No Till’ Groundswell day, organised by pioneering Hertfordshire farming family The Cherrys last year. In 2017, they added an extra day, which focused on bringing cattle back onto the land.
Tom Chapman
Tom Chapman (left) and Paul Cherry
The day started with Tom Chapman, a member of the Pasture Fed Livestock Association, talking about the practicalities of mob grazing in the UK.
Having read a Nuffield Scholarship report on mob grazing, he immediately rushed out and set up electric fences on fields where the suckler herd was set stocked. He felt this might give him some control – as the animals were now only grazing the bits he wanted them to!
After completing his own Nuffield study in 2012, he changed the herd to all spring calving and transitioned the breed away from dairy genetics to the Sussex breed, which live on next to nothing in winter.
What is mob grazing?
Mob grazing, Tom explained is short duration, high density grazing with a long grass recovery time from 40 to 100 days or longer. This allows mature grass plants with deep rooting systems to build higher quality soil. The cattle eat the top third of the grass and trample some on the soil surface – so earthworms can reach it to pull it down into the soil.
Set stocking which has no recovery period exhausts the plant, using all its energy to produce a new young shoot, which is then nipped out by the animals as soon as it appears, repeatedly. The plant then dies and weeds come in to fill the space.
“In mob-grazing grazing is restricted to maximise the amount of photosynthesis that goes on in the plants,” explained Tom. “We are using grass to lock in the sun’s energy. Arable farmers with dead crops and bare soil from July to October are wasting all the potential energy arriving from the sun onto their soil. Having livestock eating crops can fill that gap and soak up the free solar energy.”
Infrastructure
Tom gave lots of tips for water and fencing which he has learnt over the years, including fencing across the centre of a water trough to allow access from both sides, using braid instead of wire because it handles repeated stretching better, and using the least amount of movable fence posts possible. In wet weather, give the animals a smaller area and keep them there for a shorter time.
“I am a huge fan of variety in the grass ley mixtures,” said Tom. “Different plants with different rooting depths provide a nutritional mixture of energy and protein and minerals. We have a little ryegrass in them, but a lot of timothy and cocksfoot and clovers and plantain and yarrow, vetches and sheep’s parsley. Even some maize and a few sunflowers. At times it is a mass of bees.
“There are many benefits.Not least keeping 300 cows and calves all together on one group means I can check every one of them every day in just ten minutes, rather than searching for them across several acres. Also keeping cattle out for six or seven weeks longer, saves a lot of money.”
Dr Christine Jones
Green plants capture sunlight and carbon dioxide and turn weathered rock minerals into fertile topsoil. Unless there are green plants there will be no soil, explained Australian Dr Christine Jones, an internationally renowned and highly respected ground cover and soils ecologist, who headlined Day One at Groundswell.
And where there are plants – soil carbon and mineral levels also rise.
“Today, soil is often regarded as an inert media that plants grow in,” said Christine. “But 85 to 90% of plant nutrient acquisition is mediated by microbes. But what feeds the microbes and with what? The answer is that plants feed the microbes with liquid carbon.
“At the bottom of the pyramid of life sits photosynthesis along with green plants, light, carbon dioxide and water. These feed the roots and associated microbes that feed and make the soil.”
Sugary fluids translocate out throughtiny root hairs and ‘communicate’ with the finger-like processes of mycorrhizal fungi,as well as making little lumps on the roots called aggregates. These aggregates have lower oxygen levels inside, which encourages bacteria that feed and fix nitrogen. These, along with many other soil organisms, all help to produce humus – the Holy Grail of fertile soil formation.
“Humus is the key driver for the nutritional status of plants, animals and people,” said Christine.“This means it is also the key driver for farm profit. Some banksin Australia are now rewarding farmers who are building humus levels.”
Christine then explained how quickly these critical pathways shut down when artificial fertiliser is applied to crops. The plant does of course have a readily available source of nitrogen and phosphate – but it will not be able to take up any of the other, between 16 to 70 nutrients it would normally take up alongside organic N and P, because the pathway has been closed. So the plant, and anything that eats it, will lose out.
How to graze
When grass is grazed short continuously, the roots will shorten and die and the soil will lose its soul and die too. The aim is to have good, fertile topsoil down to one metre depth.
A plant can have 50% of its leaves removed and its roots will remain intact. But if 70% of a plant is grazed, half the roots will stop growing for three weeks.
If the plant is 90% grazed – all of its roots will stop growing for three weeks. Not good news for rotational grazers or set stockers that over-graze.
Christine also said that ideally fields should have different types of roots and that mixed herbal leys offer the best opportunities for building good soil. Sward diversity is good for animal health. Mycorrhizal fungi do not exist well under monocultures.
In fact ‘diversity’ became the key word of the session and the day. Diverse swards offer lots of positives – better animal health, better soil health and structure and the need for less artificial inputs. Diversity also produces a common mycorrhizal network, which likes being connected to a lot of different plants.
“95% of the life on a farm is in the soil and most is invisible to the naked eye,” concluded Christine. “Less than 1% of these organisms are known and have names and most soil microbes cannot be cultured in laboratories. There is still an awful lot to learn.”
Moving the mob
After lunch it was time to briefly venture outside to see John Cherry move his 120beef shorthorn cow and calf suckler herd for the day. The animals were quietly grazing their plot of permanent pasture – but were very happy to move on to the next day’s plot. It took John less than ten minutes. Simple.
Meanwhile, James Daniel of Precision Grazing was showcasing the latest in fencing – making it quick and easy for one person to take down and erect new front and back fences. He uses Kiwitech, innovative equipment made, tried and tested in New Zealand for the past 30 years and now for sale for the first time in the UK.
Dung beetles
Back inside the conference barn to a passionate talk by dung beetle enthusiast Dr Sarah Beynon. She told delegates that this hugely nutrient-rich resource is a package of natural fertiliser. She reckoned that her Aberdeen Angus bull produces nine tonnes a year, so with 10 million cattle in the UK that means 90 million tonnes produced a year. This could annually cover 4.8% of the permanent pasture in the UK.Thank goodness for the 47 species of dung beetles that work hard to decompose it all.
The dung ‘dwellers’ and ‘tunnellers’ have different jobs to do within the pat. Earthworms will not go into dung unless yellow dung flies and the dung beetles have been working there before them – it is a successive community.
Sadly dung beetles are in decline due to insecticides/wormers used on cattle and sheep. Sarah urges responsible use by farmers guided by facts and faecal egg counts rather than regular routine use.
Earthworm Arms
So that was the first day of Groundswell 2017. A well thought out, well attended show that taps into a growing realization that the approach to farming needs to change – based on biology not chemistry.
Thanks must go to John, Paul, Alex and Harriet Cherry and their team for hosting this innovative event, including delicious 100% grass-fed beef rolls for lunch, drinks from the Earthworm Arms bar, a fascinating book shop in the Black Barn and take-away, eco-friendly hot mugs and water bottles.
Day 2 focused on the success of continuous no-till farming that has been practiced at Lannock Farm for the past six years. Many hundreds of farmers were expected to attend.
How does mob grazing work for the milking portion of a dairy herd ?
To be honest John I have only really heard people talk about mob grazing for beef and sheep and dairy young stock.You could do it but would need enough land to have very long rotations? I will look at some of my books and try and find out!