When soil health qualifies for a mention at the Conservative Party conference, as it did this year, featuring in Environment Secretary Michael Gove’s speech, you can be sure it is firmly on the political agenda.
Earlier this year it was announced a Bill will be brought before Parliament to improve the health of the UK’s soils.
At the time, Michael Gove’s Parliamentary Private Secretary Rebecca Pow said: “Healthy soil is essential and there are ways of measuring it, such as organic matter in the soil. Farmers can be given incentives to improve soil management, such as a crop rotation. It has taken a long time, but I think we have turned the corner on getting soil on the political agenda.”
Following the recent pub- lication of the Agriculture Bill, it seems delivering improved soil health will also be one of the ways farmers will be rewarded for providing ‘public goods’ and Farming Minister George Eustice is on record as saying soil will be ‘at the heart’ of the Government’s strategy.
All of this follows on from headlines in recent years, such as ‘Soil loss: an unfolding global disaster’, and predictions of only 100 harvests left before soil is too degraded to produce a crop.
In June 2015, a report from the Committee on Climate Change reported soil erosion was a major threat to Britain’s food supply. Deep ploughing, short rotations and large fields were identified as key causes of soil erosion and degradation.
Roundup specialist Barrie Hunt agrees there has been greater emphasis on the importance of soil health in recent years.
He says: “As we go forward, we are going to see an increasing emphasis on all those areas. For far too long, soil has been considered as a ‘planting medium’.
“It is almost like it is vermi- culite to which you added a source of nutrients. Our assessment of the type of soil was down to rubbing it between your fingers and seeing if it ‘squeaked’ and how much clay was in there.
“We need a more sophistic- ated approach, which sees soil almost as a living organism which is very important to the growing process. There is increasing evidence soil health is not just of benefit to soil, but will benefit the health of crops and help increase yields. Investing time and effort in soils makes sense from a business perspective.”
Andrew Richards is a senior agronomist with Agrii and co-chairman of the Har- per Adams Soil and Water Management Centre.
He says: “We need to take the attitude soil is not just something we beat into shape with metal to plant our crops, it is a living organism and the better we look after it, the better it will look after you.
“There has been a growing use of min-till and, as people do less tillage, they need their soils to be working in a functional way.
“Issues around things such as black-grass have made people think more about soils in terms of drainage and organic matter.”
Andrew is involved with the work to find the best agreed ways for the Government to measure soil health and he believes it will be a difficult task, given the range of soil type, cropping and local environment variation across the UK.
He says: “One way of assessing is to look at rotation, which is what they do in some organic systems, and you get so many points at different aspects of the rotation. If they were to look at paying on organic matter, it is very difficult to see how it will work, depending on the type of soil you have to start with. There are more sophisticated tests on the way, but it will be a year or two before these are available.”
Barrie Hunt shares Andrew’s uncertainty about what metrics the Government will use to assess soil health, whether it is nutrient levels, organic matter or macro-flora and micro-flora.
He says: “At this stage, there does not seem to be a standard assessment for soil health.”
It is not just the Government which is concerned about soil health and nutrient levels. Water authorities also have a vested interest in soil health.
Mr Hunt and his colleagues have been working with Wessex Water, which is paying farmers to grow cover crops in strategic locations to capture nutrients which otherwise might find their way into the water supply.
Andrew Richards admits testing soil health is difficult, as unlike testing for nutrients, there are qualitative and dynamic factors which vary throughout the year.
As a result, there is no simple single test that can be done which will give a full picture of soil health, but it is better to do something than nothing at all.
Drainage and organic matter are critical factors, while both AHDB and Rothamsted provide useful guidance on simple checks on biology using earthworm counts.
Services such as SOYL and Soilquest offer conductivity testing which can help to build a soil map of land, enabling you to develop a strategy for variable nutrient application.
Ultimately, Mr Hunt sees a role for a more sophisticated testing regime including assessing mycorrhizae.
He says: “There has been a lots of interest in this area. I was talking to a farmer in North Lincolnshire who was in a min-till environment and was building quite a complex rotation to maximise his mycorrhizae and, therefore, his soil health.
“One of the crops in his rotation is oilseed rape, but to build his mycorrhizae, he is having to extend the rape rotation. He has to build up mycorrhizae before planting rape because it has no mycorrhizal relationships.”
Reduced tillage has become a proven route to the improvement of soil health.
Barrie Hunt says: “By driving the accumulation of organic matter and improving general soil micro-biological health, reduced tillage can help improve overall soil health.
“I think most growers out there are practising some minimal cultivations. There are not many that plough every acre.
“For those planting oilseed rape, they want to preserve as much moisture in the soil as possible.
“So there is a range, from those who are just doing some min-till through to those who are not doing any tillage at all. Some of that can be very impressive; we have people who are growing cover crops prior to spring cropping. They will go in and spray in spring, then drill straight into the cover crop. They are achieving good results, but it takes a lot of heartache and hard work to get to that stage and maintain it.”
Alex Birchall is product specialist with Kuhn and recently completed research looking at means of establishment on arable farms.
He says: “While min-till is gradually becoming more accepted, the cost of equipment is still a barrier for many farmers. It is also true that the age profile of those taking decisions works against innovation, and there tends to be an attitude of ‘it has worked for the past 50 years, why change it?’ However, the younger generation is certainly willing to embrace new technology.
“Recent advances in drill design have allowed many farmers to adopt a min-till establishment approach.
“In the past, limitations in a drill’s ability to cope with trash meant growers were creating conditions to allow a drill to operate, whereas now they are able to create a seedbed for the seed. This saves establishment and, more importantly, allows optimum seed placement to ensure even and consistent crop establishment.”