Last December, I visited a number of farms to look at the general state of the soil being farmed. The farm types were drystock, dairy and tillage and a video made from those visits should be viewed in full to show the different characteristics and challenges in soils as influenced by how they are managed.
I was joined for those discussions on soil health by David Wall from Teagasc Johnstown Castle and David Cooney from Glanbia. The farmers we visited were Francie Gorman, a drystock farmer near Abbeyleix, Shane O’Loughlin, a dairy farmer near Monasterevin, and James Ashore, a tillage and beef farmer farming beside the M9 east of Athy.
The video produced was a product of the Sustainable Farm Insights programme carried weekly in the Irish Farmers Journal and supported by Glanbia Ireland. We have looked at many different aspects of soils in recent months and this video, to be released next week, aims to bring those messages to life and show the benefit of good soil care in real fields on real farms.
The overall objective of this programme is to point out the things that we can do to make our resources work harder for us and to convert this into profit for farmers. It all starts with your soil and that is as good as how you manage it.
A healthy soil is less easily damaged
Soil health is built on the combination of its physical (structure), chemical (fertility) and biological (the billions of organisms that inhabit it) characteristics. Together, these three pillars help your soil to give you more so you need to apply less. A healthy soil is less easily damaged.
It provides more of the total nutrients and it does other things that help to protect our environment. Our three visits explain how these happens in practice.
Healthy soil is resilient
Our first stop was on the farm of Francie Gorman, a beef and sheep farmer near Abbeyleix, Co Laois.
Grass production is very important here, with ongoing care for the soil and very little reseeding.
Grass growth is good on the farm and fertility, lime and dung are important tools to help performance.
We visited one of Francie’s pastures where sheep were grazing. This was a very dense sward with lots of grass present. David Wall dug up an 8x8x8in cube to look at how the soil behaved.
A few things were immediately obvious in this traditional sod – the soil structure looked excellent, the sod was held together by the multiplicity of roots and there were many roots going much deeper than the sod.
While soil structure was visibly good, it was not possible to break the top of the sod apart by hand.
The whole thing was a mass of roots that do two other things as well as holding the soil together:
These things together give great resilience to this soil, help it cope better with adversity and to recover much faster if the soil is damaged.
Roots are a carbon store and the deeper they go, the safer that carbon is.
Visible tightening under grass
Shane O’Loughlin’s dairy farm in south Kildare focuses on growing as much grass as possible and using it in as wide a window as is practical. He has access lots of land around him and that helps relieve the pressure from intensive management.
He soil-samples regularly, and most of his land is now Index 3, with pH generally above 6.2 and sometimes exceeding 7. He still applies lime in areas where the pH is lower and Shane sees lime as the lubrication for nutrient flow in the soil.
He has high grass growth levels. We dug two sods in a field that had been reseeded about 10 years ago. The first was from a spot where the sod had been damaged.
When the tight sod was broken, it was easy to remake the pieces
While the 8x8x8in cube had a nice friable structure at its base, this fell away when the sod was lifted, leaving three to four inches of tighter soil with very few roots penetrating deep.
Shane was conscious of this tightness and is tackling it using dung. When the tight sod was broken, it was easy to remake the pieces. This is indicative of failing structure which could limit growth.
Close by, David Wall dug up another cube in an area under a dung pad. As it was being lifted, earthworms were visible and numerous. The soil structure was different – almost all the soil fell away and broke up easily because the structure had been improved by the biological activity.
Dung produces the same effect. As well as carrying nutrients, dung is like a magnet for earthworms and when they find it, they congregate and multiply.
This feeding pulls the fertility down into the ground and improves structure.
Any food for earthworms has the same effect but dung is top of the menu. Its use should be maximised rather than minimised in intensive grazing situations.
Poor structure, low organic matter and compaction are common problems in tillage soils. However, the field we visited was different.
James Ashmore has been actively trying to improve the structure and productivity of his soils for more than a decade. He is a mixed farmer, which gives him an advantage in terms of recycling nutrient, but he is doing much more. He is also growing catch crops and legumes and uses three years in grass in his nine-year rotation.
Having plants growing all the time helps to protect the soil and some tap roots had gone down 12 to 14 inches
That three-year break provides a rest from cultivation, helps to rebuild carbon and structure and it helps to decrease the general weed burden. Good soil structure was evident in his catch crop field that we visited.
Having plants growing all the time helps to protect the soil and some tap roots had gone down 12 to 14 inches.
These partly act as water pumps and they also put carbon down into the soil profile. And good soil structure means good root soil contact to access nutrients.
James continues to plough but he has improved soil structure and organic matter by the sensible use of organic manures, catch crops and his three-year break.
The improvement is giving him a wider planting window, cultivation requires less energy and his yield levels have increased.
The added resilience meant that he was barely affected by the recent drought years.