Oral evidence: Soil health inquiry, HC 653Tuesday 12 April 2016
Oral evidence, 12 April 2016.
Witnesses
Professor Dave Chadwick, University of Bangor, and Professor Jim Harris, Cranfield University, gave evidence.
Chair
We are moving into public session now. I am happy to welcome Professor Jim Harris from Cranfield University, a former colleague of mine, although I think you are from the Silsoe campus, are you?
Professor Harris
Originally, yes.
Chair
Yes, is everything merged into Milton Keynes?
Professor Harris
It is all at the Cranfield campus now, yes.
Chair
It is all at Cranfield, good to know. And Professor David Chadwick from Bangor University. Apologies for starting slightly late. I wonder if you could describe the recent development in Wales where soil quality has been integrated into wellbeing indicators. Tell us a little bit about how it has worked. Have there been any changes in policy and practice? Would you like to start?
Professor Chadwick
The first thing to say is soil we can see is clearly viewed as a critical, natural asset resource within Wales, so much so that soil and soil carbon in particular is now one of the key indicators within the Well-being of Future Generations Act. That sits within other broad indicators like healthy life expectancy, gross domestic disposable income, and water and air quality, that sort of thing, so it sits within a very broad spectrum now of an Act that brings together a number of different Government bodies to work together. The Act has lots of different goals. These goals are to generate a resilient Wales, a more prosperous Wales, a Wales that has more community structure and a healthier Wales. So they see soil—this is important—as sitting as one of these assets that can help to deliver economy, wellbeing and resilience of course and a corporately responsible Wales within the world.
Chair
What changes have there been in policy and practice as a result of this?
Professor Chadwick
From a government perspective, I think probably not a great deal of change in terms of management but much more greater acceptance that soil is a key asset and a key piece of natural capital within Wales. I can tell you more about the monitoring programmes and things like that, but I am not sure it fits exactly with the discussion. I can if you want me to.
Chair
Yes, can you talk a little bit about it and what are the costs and benefits or is it too early to say?
Professor Chadwick
First of all, I can tell you the costs of running the programme at the moment, the programme of monitoring and evaluating the Glastir programme. Glastir is the environmental stewardship scheme within Wales that has wrapped up all the previous schemes and brought them into one. It is what delivers the farmer payments to deliver different ecosystem services. Those ecosystem services are all about trying to halt the decline of biodiversity, improve water quality and increase carbon sequestration, those sorts of things. The Welsh Government obviously took guidance from the EU to find out what it was allowed to do, what it could do to monitor and evaluate how successful these payments to farmers are in delivering those ecosystem services. They were obviously guided by the EU that they could spend up to a certain amount of money. I think it is something like 2% of the RDP payments can be spent on some kind of evaluation. So they put forward and developed a monitoring evaluation programme, with lots of statistical advice about how it should be done, to monitor the impacts of these interventions that farmers can select. The farmers can select from menus of different interventions that can earn them points, earn them money, but helps to deliver to whatever specific ecosystem service there might be. The Welsh Government has been slightly clever there and what it has done is it has targeted certain areas of Wales where it says, “This is the place where we need people and restoration”. Whereas somewhere else it might be, “This is where we are willing to concentrate on water quality”. While the menu of different interventions remains the same for the farmers, they get more payment for a particular intervention that delivers that ecosystem service in that area. It is a sort of targeted approach. It is too early to say where we are. We have been running now for nearly four years, and the statistical design means that 75 one-kilometre square areas are randomly selected each year. Within that there are two cohorts of squares: one set of squares that are called the wider Wales, where we try to get information. The sort of control population where there are not a lot of payments through ecosystem services through Glastir, and the other half is where there is a lot more payment. There have been 300 squares now over four years that have been monitored and the idea is that we repeat the monitoring every four years, so the next year is the time to repeat that monitoring.
Chair
Great. Thank you that is very helpful.
Peter Aldous
What do you think that Defra could learn from the approaches of the Welsh and Scottish Governments towards soil?
Professor Chadwick
I am afraid I cannot comment on the Scottish side but from the Welsh side—and I am not too sure whether this is already happening within Defra, so forgive me if it is—there are two things I want to state. One is that there is more integration of the mainstream of soil within the different departments, so you are not just thinking of soil as just one thing in isolation. It is the realisation that soil is pivotal in the delivery of multiple ecosystem services. I think that is probably quite useful for the Welsh Government to bring them together from a department perspective. The other thing is—maybe it is already happening slightly through the Countryside Survey—the sort of multipurpose monitoring schemes that are very much not just about going out and measuring soil but what is the quality of the water? In the same area what is the quality of the biodiversity, is it increasing, is it decreasing? Even to the extent with the Glastir Monitoring and Evaluation Programme we are also looking at access to the countryside, are historical features being preserved or not? So it is quite broad in that respect. That multipurpose approach obviously gives good cost benefit, cost effectiveness. It brings the different departments together and—really importantly—it allows you to start to see where any win/wins might be or where any undesirable consequences might be. Otherwise, if you had one team measuring soil over here, another team measuring biodiversity over there, you don’t get that joining up until probably much later in the process.
Professor Harris
I would like to agree with that and suggest that one of the overarching lessons coming from this is that, unless we start to integrate these different types of data and analysis, we are not going to get to a holistic answer and the outcomes that we are interested in, in terms of human wellbeing and societal outcomes in general. It is important at this stage to say that one of the lessons perhaps for Defra will be that the two 25-year reviews, which are absolutely welcome, need to be integrating across with soils, landscape and that kind of thing. Perhaps it might be done as a single review but that is what is happening at the moment across land use. The more sophisticated programme going on in Wales at the moment is going to teach us a lot about this kind of integrated assessment. I think it is extremely important that we start to integrate with the water quality data that we have from the EA already that is being collected regularly; trying to get that working together in terms of biology, chemistry and so on, and to try to get across the rural/urban divide and Defra and DCLG working together. I am intrigued by the earlier discussion today. This idea of managing urban areas within a landscape has to take proper notice of the interactions and the co-management of grey, green and blue infrastructure. We are starting to make advances in understanding how they interact. We are starting to make big advances in understanding what there are in terms of health and general wellbeing outcomes, but unless we start to look at all of these things in an integrated way we will be forever—I don’t know if anyone has ever tried to put a tent up in the wind—putting one bit down and grabbing another bit. We have to try to do all this together.
Peter Aldous
Looking at it from the other way round, are there any other English practices or policies that outshine those of the devolved nations?
Professor Chadwick
I am not so sure. No.
Peter Aldous
No. Perhaps you might feel this is an aspect of government is better done at a devolved level?
Professor Chadwick
It might be better organised at a devolved level but at some stage I think, because of the sort of things we are talking about, we are talking about global agriculture. We are certainly talking about the UK-wide agriculture, so any future monitoring programmes I would suggest would certainly need to be co-ordinated and aligned, not least between the different devolved administrations but also with whatever else is going on now. There are certain monitoring programmes going on now and probably certain ones that are being planned. It just needs some co-ordination.
Professor Harris
Yes, if I could add to that, I think that it is important that we start to carry on rolling out the idea that the basic unit of interest in the landscape is the catchment, because that is how you can really start to understand the integrated outcomes in terms of things like water quality and so on. That then might be well organised regionally in terms of the doing and the reporting, but we need to have a view, which could be scaled up nationally and internationally, to understand where we fit in the whole scheme of things.
Margaret Greenwood
First, to Professor Harris: how could Defra use its upcoming 25-year plan to set cross-Government goals to promote soil health?
Professor Harris
The great advance I think has been in pioneering globally the natural capital ecosystem service approach to understanding impacts but also benefits. If Defra can take that across Government to understand what the impacts are of policies, what opportunities there are for investment in this national infrastructure that is so important—soils are a fundamental asset, obviously, in terms of delivering that—and align natural capital with our understanding of what is happening in the other four capitals that are important for us—social capital, human capital, built/manufactured capital and financial capital—if we can align those together we will start to get a good picture of what the things are that degrade those services coming and the ways in which we can improve and invest in particular areas. We make an investment in a road, but what are the implications for natural capital and what are the implications for social and other capital? It is very complex, but a lot of the conceptual work has already been well done and well understood.
Margaret Greenwood
I am wondering, aside from Defra. which other departments from Government should be involved.
Professor Harris
Well, I am tempted to say Treasury, DCLG definitely, but there are implications for most Government Departments in one way or another because if you think about the five capitals, that is the business of Government. Consequently, there will be implications for all of them.
Margaret Greenwood
Thank you. I do not know whether Professor Chadwick would like to comment on this.
Professor Chadwick
I think I would just agree. I have only been living in Wales for three years; in fact, I do not even live there now but I mean I have been working in Wales for three years. I can see already the “joined-up-ness” within what I can see of Welsh Government anyway. I get exposed to Welsh Government from time to time and this Well-being Act is something that sets soil within a much broader, very, very broad spectrum about protecting resources for future generations. I think it is maybe something that Defra could also think about.
Margaret Greenwood
Very interesting. More generally, what should Defra’s long-term priorities be for soil health in its 25-year plan?
Professor Chadwick
The long-term strategy should be about understanding what it has, understanding the stock, the state of the health of what it has in terms of soils and what it delivers, and then setting up or continuing to set up a monitoring programme that allows it to capture the evidence that its policies are working or not. It needs to be at the right kind of spatial and temporal kind of resolution, and it reports regularly so that they can act upon whether these indicators, whatever are going to be used, are making the desired change or not and keeping a watching brief on it.
Professor Harris
I think that it is important that Defra sets the direction of travel for not only protection and conservation of what we have but restoration of natural capital and general soils in particular. It is very difficult sometimes to talk about soils in isolation. You have to think of them as part of a system, and I am interested across the whole spectrum from intensive agriculture through urban to natural systems. I think that there is an opportunity there to make some quite bold statements about wishing to improve, enhance and restore in addition to protect and conserve.
Professor Chadwick
Sorry, I might just add that there is also in the long term a need—I think it was mentioned before—for additional training and education. Again, in Wales we have the Farming Connect programme. That is an RDP-funded programme that is there to upskill and to help innovate within the farming systems that we have in Wales and that includes training, demonstrations—we certainly have demonstrations for soils—and, in fact, it also includes a subsidised soil test for farmers. There are certain things we can still encourage, I think, through training and education.
Chair
Thank you. That is very helpful.
Rebecca Pow
We have heard from previous witnesses that they recommended the Government should consider some sort of soil national monitoring scheme of soil health; particularly the Soil Association I think recommended that and various other people. Do you think that would be affordable and do you think it is something we should look at?
Professor Chadwick
Yes, I think weighing up the cost-benefit is difficult because how you put a value on soil, per se, is not an easy thing to do. There will be people out there who do it based on the ecosystem services that they generate, but it is clear, for example, that the Welsh Government thinks it is a natural asset that is certainly worth preserving. In terms of the Welsh monitoring and evaluation programme that we have that includes soil, the total programme costs around £8.5 million, or has cost for four years of running, and the soil component of that represents around 12% of that value. That is covering these 300 squares, one-kilometre grid squares, and, as I say, that will be repeated next year when we start the process again.
Rebecca Pow
Do you think that model could be rolled out nationally?
Professor Chadwick
I think it can. I personally think if it is rolled out we will have lessons to learn, I am sure, from the Glastir Monitoring and Evaluation Programme, but I think in principle it should be taken forward, thinking carefully about doing it as a multipurpose programme, not just soil per se.
Rebecca Pow
Would you say that without doing a monitoring process it is difficult to prove that we need to take soil seriously?
Professor Chadwick
Yes, absolutely. How can you sit in your chairs—or not you, how can policymakers sit in their chairs and say that their policies are having an effect if they do not have the necessary data and evidence base behind it?
Margaret Greenwood
Sorry, Professor Harris, I will come on to you because I know you have some expertise in this. Do you think it is something that the new Defra analysis unit should take on board, which is all about getting statistics and economics? It has just recently been formed.
Professor Chadwick
Well, maybe. I was in Brussels last week visiting various departments there and I was fortunate enough to visit the Joint Research Centre, which is their internal research arm, I guess; the EU’s research arm. They were discussing very candidly the revisiting of the soil framework directive that was pulled some time ago and they were specifically saying the first step, if they were to take this forward, would be to do some sort of EU-wide gap analysis on soil policy. That would probably include, I guess, the soil monitoring that helped to provide the evidence base as well. So I think yes.
Rebecca Pow
Thank you. Professor Harris, I know you have particular expertise in soil biological communities.
Professor Harris
Yes, thank you. I am glad that is on the record.
Rebecca Pow
Would you like to enlighten us on how that fits into the potential that we ought to have a soil monitoring programme?
Professor Harris
Yes, I think it does and we have some very sophisticated and very clear understanding of relationships between land use pressures and uses on the biological community in association with the chemical and physical effects. There are ways in which we can examine the configuration of the communities, the biodiversity of the communities. We need to do more on the way that they are connected with one another, how the effects of the different land use pressures affect the state of those communities, how that then plays out in terms of things like water storage to prevent flooding, carbon sequestration production, aesthetic value and health aspects, as have already been touched upon. There is work going on at the moment. I have done some work on thermodynamic efficiency of soil communities, which shows that in areas where intensive organic inputs are used the microbial communities have to work twice as hard to produce twice as much waste heat as those with organic input, so we can get some quite sophisticated measures of the way in which the community responds to that. The affordability of these things goes on the scale of how close you are to the TRL level and some of these are at an early stage, but others are quite tried and tested.
Rebecca Pow
Sorry, TRL?
Professor Harris
Sorry, the technology readiness levels that you would say: is it ready to go and be deployed or does it still need more proof of concept work, more development to bring costs down, and so on? We have quite a good range of techniques that can already be deployed. There are new methodologies coming out at the moment. People are looking at things like near-infrared spectrum analysis. People are interested in things like volatile organics coming from soils; what does that tell us about the state of the soil and the way in which communities are interconnected in the soil but also with the plant communities and the animal communities, the whole ecosystem? I am going to have to try to rein myself in here or we will be here forever, but it is an incredibly exciting area.
Rebecca Pow
Do you think we should beware not to have an isolated soil monitoring system, say it was introduced?
Professor Harris
Yes.
Rebecca Pow
Yet another isolated thing that is not connected up with all the different departments. Do you think we should go along the Welsh model where you are including also soil, all the different biological communities, all the different aspects?
Professor Harris
Yes, I think too often where we have concentrated on one kind of parameter, and organic matter is fantastically important, of course it is, it is the centre of a lot of these, but it will only tell you so much. What is more, the time it takes to change it in the direction that you want to means that you may not get an early indication of success or lack of progress, and that is where some of these other measures can be very useful. I would also like to say I think that this needs to be done in a spatially explicit way. It has to be done and mapped, and we can do that. The UK leads the world in many of these ways with what we have done. We have the Countryside Survey, the National Soil Map, and so on. We could be not only doing the best that we can do but leading the world in demonstrating, educating, researching.
Rebecca Pow
Do you think we ought to get a move on? Are you ready to go? The other witnesses we saw on the more soil testing side, they also claimed they were ready to go with all this knowledge on their ideas they had about soil monitoring. If you put all the ideas together, it would not be impossible to roll something out, would it?
Professor Chadwick
Not at all.
Professor Harris
We are scientists. We need more research; we are always going to say that. We need investment, but we are ready to go in many of these things.
Chair
You are saying the UK has a natural intellectual competitive advantage in this area vis-à-vis most other countries in the world?
Professor Harris
UK environmental research really punches above its weight in this and other areas. It really does.
Rebecca Pow
Is that in conjunction with Europe or separate from Europe?
Professor Harris
There is lots of fantastically important work done with European colleagues where they are learning from what we are doing and we are learning from them, but in terms of looking at outputs from the research community, environmental research is really, really—
Professor Chadwick
I would like to add to that. We have talked very much about measurements here and, of course, they are absolutely critical but you cannot measure everything everywhere. You just cannot. We have to rely on good simulation models and that is another area in which I would say that the UK does extremely well. We have models that help us to interpolate between values that we don’t have, and we use the monitoring data that we have to help verify whether those models are working correctly or not. It is a combination of the two. When do you stop making your measurements, at what spatial resolution? I think it is a combination.
Mr Lilley
You mentioned the National Soil Map. I was not aware of the existence of this. Could you tell us a little more about it?
Professor Harris
Yes. Over the course of the last several decades, England and Wales had the National Soil Survey and Scotland had its equivalent. As a result of that, we have quite a sophisticated map of soil resources in the United Kingdom.
Mr Lilley
That sounds as if they must have done the monitoring on a grid basis.
Professor Harris
That is very much on the basis of describing the taxonomy of the soils as to whether they are dominated by clays or by peat or what have you. It is very much a framework for: these are the types of soils; are they loams, clay loams? Where are they? What is the geological history that has led to the disposition of these soils in particular places? You can use that as a basis for then investigating different kinds of parameter that we could build into that kind of approach.
Chair
When was the last soil survey done? Are they a 10-yearly thing?
Professor Harris
No. It links in with the Countryside Survey, but there is not an ongoing programme as such. It was several years ago since it has been refreshed, although it has been refreshed in some areas.
Rebecca Pow
There were two maps, weren’t there? There was the Soil Survey of England and Wales and there was the land classification, ie the grades 1 to 5 of agricultural land.
Professor Harris
Now, that is interesting. That is right.
Rebecca Pow
Are they still both existing?
Professor Harris
Yes.
Rebecca Pow
Because I did my university dissertation on this.
Professor Harris
Oh, right, excellent.
Chair
You might want to submit it as evidence.
Rebecca Pow
I have never heard of the second one since.
Chair
We will have that in as evidence.
Rebecca Pow
But I am not an expert.
Professor Harris
There is the Soil Survey, which is a map, and then the agricultural land classification, and then there is a land use classification. Essentially, the agricultural land classification gives an indication of how flexible the soil and land is in terms of producing crops. On grade 1 land you can grow virtually anything, whereas on the lowest grade, seven—it is divided into nine, but three is divided into A, B and C. As you move from one down to seven, you move to areas where it is almost impossible to grow anything. However, that does not mean to say that grade 7 land isn’t producing ecosystem services. It is and it might be because that is a granite woodland. I always give the example of Wistman’s Wood in the West Country; I do not know why. You cannot grow anything on it but it is a fantastically important area for wildlife and for people to visit. There is that classification. That is used in planning, but my understanding currently—and you were talking earlier about capacity and capability in local authorities—is any parcel of land that is smaller than 20 hectares—I think this is the case—no longer gets referred to the national expert body, which is Natural England in this case. That is dealt with locally and then a decision has to be made about balancing the needs for development with the needs of agricultural production.
Rebecca Pow
Just to stop you there, though, I know about those maps, but why can our suggested soil monitoring scheme nationally not just fit in with those maps? Wouldn’t you just put the new monitoring scheme that is being mooted into those maps?
Professor Chadwick
Yes, the idea is that you use those maps in layers. You want to make sure you are covering the right level and range of land uses on geological soil types. Although you would have a randomised kind of sampling strategy, it has to be strategically randomised. I cannot think of the actual word now. You have to have the right kind of stratification for it.
Professor Harris
Representative.
Professor Chadwick
Thank you, yes.
Chair
Thanks. We are going to move it on. I think you have sort of covered that. Professor Harris, you said indicators, organic matter is important but you think your biological communities are important as well. What sort of percentage values would you give them, 80/20 or 50/50 in terms of the indicator development?
Professor Harris
It very much depends on the question that you are asking. If you want to make a clear description about what the impact of agricultural practice on organic matter is, that is all that you really need to ask. But if you wanted something that was going to give you a more comprehensive picture of the state of the system that you are interested in, I would give equal weight to those chemical, physical and biological characteristics.
Chair
Thank you. That is very helpful.
Margaret Greenwood
Professor Harris, you have been involved in research into the total cost of soil segregation in England and Wales. I thought perhaps you could tell us a bit more about how you came to the £1.2 billion per year figure.
Professor Harris
I have to say at the beginning that I am not an economist. My part in this work was as a soil biologist helping to contribute to the discussion and the general concepts. Essentially, work done by Dr Graves and others at Cranfield with ourselves looked at that soil map, looked at what we knew about degradation and, in particular, offsite consequences of things like compaction on flood risk, for example, erosion on water quality, and as a result of that came to an estimate of between £0.9 billion and £1.4 billion per annum, in terms of costs of soil degradation across England and Wales. It is England and Wales because that is the England and Wales soil map. You could do a similar exercise for Scotland if you wanted to. The split of where the costs lie for that was 47% came from loss of organic matter, about—sorry, I am going to have to put one of my pairs of spectacles on to get it absolutely right—39% from compaction and about 12% from erosion. Of course, there are interplays between those when it comes to the aggregated cost because you might get a flood but also, with that, you will bring in soil contamination in the sense of suspended solids that have to then be dealt with in a water treatment plant, for example.
Margaret Greenwood
When you are talking about offsite being of limited concern to those whose actions may be causing soil degradation, what kinds of costs are these? You have mentioned a little bit, but perhaps you could tell us a bit more about this and the impact it has on the policies and incentives required to curb this happening.
Professor Harris
We have seen this. The starkest example is the most recent one of flooding in the Uplands where, if your policy focus for a particular area of farming of a particular type has no relation to what is happening elsewhere in the catchment, inevitably you are not going to be able to account for those costs on the farm that will be accounted for in terms of insurance and reinsurance costs, in urban areas the costs of flood protection. That is the causal link and that is the scientific link that has been identified clearly that there are implications for having unwooded landscapes devoted to areas that, in effect, generate water because much of that agricultural practice and engineering work has been around getting water off the land quickly. Of course, you would if you want to continue to provide feed for animals and for growing crops. You cannot have something that is waterlogged all the time. Inevitably, then you are shifting the problem somewhere else and that is where the costs are borne.
Margaret Greenwood
Right, okay. Thank you. To what extent are soil-based strategies for addressing flood risk being taken seriously, do you feel?
Professor Harris
I feel they are now being taken very seriously.
Margaret Greenwood
Yes. Finally, based on your estimates, what policy initiatives would have the largest impact on reducing the cost of soil degradation?
Professor Harris
We need to think about this kind of scheme that Professor Chadwick has described and integrate that—like I have said earlier—at a catchment scale to start to link the land uses to the outcomes within the catchment. You could then look at the way in which you can incentivise landowners to manage land so that the multiple benefits can be achieved, restoration where possible, things like tree planting and so on. There is no single answer. It will be a combination of these things. There are some impediments to that. For example, in my understanding, my opinion from what I have seen is that the things designated as PIFs I think they are—permanent ineligible features—if a farmer puts a piece of land into woodland, they are then taken out of the farm payment calculation. Clearly, there is a problem there for a farmer who is trying to do something for somewhere else in the catchment. I think then that we can start to look at the way in which this knowledge is transferred and imparted. You need to be able to enable a term that I have often used called trusted intermediary between farmers, landowners, and the way in which they can understand and work in that environment because it is incredibly complex. If you are a small farmer, it is a lot to take on. If I start talking to a farmer about genetic analysis of microbial communities, I don’t suppose I would get a cup of tea at the end of the day. I think that it is important that we recognise that there is a gap there in knowledge transfer linked with incentivisation. The EA started to make moves in that direction with catchment-sensitive farming officers and it is rather redolent of the old days of ADAS when there was a link between farmers and advisory agency and research and ideas flowed backwards and forwards: we have a problem on these farms; can we commission a piece of work and get that out? That kind of pipeline of knowledge and inquiry, it would be great if we could have something like that.
Professor Chadwick
Just to follow up on that, Defra is sponsoring two projects at the moment on the sustainable agricultural intensification theme. One of those is at the catchment scale trying to address what the barriers are between farmers stopping them collaborating for exactly these kind of reasons, to get maximum use of the land for various ecosystem services, and what are the incentives that need to be put in place. In fact, tomorrow and Thursday we have a two-day workshop over at Bangor on this subject, but it is early days yet to see where we are.
Chair
That is helpful. Thank you. Before I move on to our closing question, this analysis of the costs and the £1.2 billion, has that been done before? Is this just a one-off or is it something you are planning to revisit?
Professor Harris
This was a one-off. It was a piece of Defra research and the paper has come out of the Defra report.
Chair
Okay, that is helpful. Thank you.
Mr Lilley
In that report, over half the costs are attributed to greenhouse gas emissions from soil. One of the things that puzzles me about our study is we are saying there is a problem but we don’t know what the problem is because we have not studied it, so we have to have a monitoring system so that we can know what is happening to the soil. I am not quite sure how we can both know there is a problem and know that we don’t know there is a problem, but how we can not know there is a problem and still be able to measure it is odd. Are we saying that we know the rate at which carbon dioxide is being emitted from the soil net? That is question 1. Question 2—because the Chairman will not let me come back—is Professor Freeman Dyson, who is a physicist and not a soil scientist, did suggest that if we could increase the CO2 capacity of soil—indeed, on the figures in our research a 10% increase would remove all the CO2 that has been added to the atmosphere since the industrial revolution. First, do we know that CO2 in the soil is declining and, secondly, would it be possible to make it increase significantly?
Chair
That is three questions.
Professor Harris
Yes, known knowns and unknown unknowns. Okay, let me try to take those. We do know we have some very broad and good estimates and measurements of CO2 production from soil. We know that this is a contributor to the greenhouse gases. We also know that there are ways in which we can reverse that loss of organic matter. There are ways in which we can manage soils to try to reverse that. I don’t know about that precise number of Dyson’s but—
Mr Lilley
Sorry, no, the number was mine from research. It said that soil contains three times as much carbon as the atmosphere and the atmosphere has increased by 30%, so you can work out the 10%.
Professor Harris
Yes. Well, that is where you could certainly bury a lot of sequester soil, organic matter and, therefore, CO2. There is also an interesting mechanism around increasing rates of erosion and increasing CO2, but that is more complicated than we need to worry about at the moment. Certainly, by managing the land to increase organic matter you will sequester more CO2 from the atmosphere.
Chair
So we do know there is a problem?
Professor Harris
Yes.
Chair
It would be better to have more refined measurements to give us a richer picture, is that what you are saying, of the scale and extent of the problem and to be able to measure the potential attempts at a solution?
Professor Harris
Yes, and in an integrated way, so coming back to: let’s not just do that, let’s try to put it in the context of these other measurements.
Chair
Okay, thank you. Sadly, you don’t get a cup of tea at the end of this session either, Professor Harris. Sorry, Professor Chadwick, did you want to come in?
Professor Chadwick
I was going to come back just slightly to say that Defra and the DAs have spent a huge amount of money recently on improving our greenhouse gas emissions inventory from agriculture. There is a huge amount of information on the nitrous oxide emissions from soils and controls on those fertilisers and manures and how best to try to reduce those; a lot of information now on the ruminant methane emissions and how they contribute and how we should try and can try to reduce those emissions; and obviously an increasing body of evidence about how we can best sequester carbon through peat land restoration and so on. There is a lot of underpinning information behind the calculations that have been made there.
Chair
Thank you. I am going to bring us to a conclusion by asking you both: what is the most important step that the Government could take to ensure that soils are managed more sustainably, one from each of you. It is a hard one.
Professor Chadwick
I think you have to know what you have in terms of stock and, therefore, you have something to work from in terms of improvements. The monitoring and evaluation is one thing, but incentivising farmers to work in such a way that this will happen, it is the education side of things again. We have talked about soil organic matter being something that is ubiquitous, really, but it has so many additional benefits that it brings with it. An increasing yield is one of them and if that is the hook, then that is the way to push it.
Professor Harris
I think incentivisation is incredibly important. You mentioned earlier, Professor Chadwick, about getting people to work together within catchments. That needs to be facilitated, but there perhaps need to be some very hard decisions made about property duties alongside property rights in this regard. There are certain things that should be done in areas that the landowner might not be keen on, so having to get over that to make sure that that happens.
Chair
Brilliant. Thank you both very, very much indeed. I bring the session to a close. Oral evidence: Soil health inquiry, HC 653 5