Oral evidence: Soil health, HC 653Wednesday 9 March 2016
Oral evidence, 9 March 2016.
Witnesses
Professor Paul Hallett, University of Aberdeen, Professor Richard Bardgett, University of Manchester, and Professor David Powlson, Rothamsted Research, gave evidence.
Chair
If I can call the Committee to order, we have our second panel. We are one person light, but we have with us Professor Hallett from the University of Aberdeen—thank you very much for joining us today—and Professor David Powlson from Rothamsted Research. We understand Professor Richard Bardgett is on his way from Manchester and currently stuck on a—
Professor Powlson
He is stuck in a flooded train, or something.
Chair
Oh, bad luck. We have all been there, so our sympathies go to him. If he is able to join us we will ask him to join as the panel goes on. We were going to kick off this panel by asking you, first of all why do you think that soil is generally not on the public radar? You sat through the previous discussion. Secondly, how successful do you think the UK is at managing soil vulnerability? What can you add that the previous panel have not told us?
Professor Powlson
As a soil scientist, I obviously have axes to grind, but it has always seemed a bit bizarre that there are legislation and policies that directly affect water and air but many of us would think that soil was pretty important in a similar sort of way, yet the legislation that affects soil is exceedingly indirect. So for example the water framework directives and nitrates for water have implications for the way that soil is managed, important implications, but it is indirect. That just seems something that has grown up. It is true that soil is rather complicated and I am not going to hide behind the, “Oh, it is too complicated; we cannot do it”. I think we can. In the sense that water and air are substances that can be seen as pure, in some sense, so you can start setting limits that you must not have more of chemical X in them or something of that sort, soil is not like that. Soils are all very variable, as we have said earlier, so you cannot say, “This is a pure soil and this one is not”. With soil it is a bit more complicated. I think you can set targets. I have some sympathy with what Peter Melchett said, and I think you can look at trends in certain properties, so it is not quite as simple but I would be very keen on seeing some policies that do directly affect soils, partly because things in soils do change slowly. If you are on the wrong trajectory you may not even know it or it certainly may not show itself for five years, 10 years, 20 years or even more. That is an issue. No, I do not think we are particularly good at managing soils in this country. Again, Defra in the past have produced various documents. I think there was one in 2009 called, “Safeguarding our Soils”. Now, as far as I know this has almost completely been not acted on, so there are lots of fine words and good stuff in that. Indeed, I think some of us probably contributed to its writing at the time, I do not know, but nothing seems to have happened. Just going back to the last session, I think the Scottish devolved authority and have done a better job of raising the profile of soil somewhat.
Chair
Thank you, Professor. Professor Hallett?
Professor Hallett
I want to disagree with the comment about the public being disconnected with soil. I think there is a portion of the public who are very concerned about it. We would not be sitting here if that was not the case. Just as David has said, it is a very difficult medium to put simple values on to, but it is possible to put values on to it so that we can classify its quality or whatever else. I am sure if you put a group of us in a room and said, “Look, here is your X amount of pounds, how are we going to test the quality of the soil?” we would come up with a solution for you. I do not think it is something that is as elusive as is being put across, and I think the public does have an interest in it. Another aspect that we have to put across as well is that internationally the threats to soil are a lot bigger than they are in the UK and that is going to put pressures on to the UK as well, and we need to keep a note of that. A lot of the science expertise that is in the UK right now is going overseas at the moment with Newton funds or whatever else to help find solutions.
Chair
Which areas do you think are particularly at risk, or particularly vulnerable?
Professor Hallett
In terms of soils?
Chair
Pressures. The US?
Professor Hallett
So basically as you get towards equatorial latitudes, things get worse. Sub-Saharan Africa is where the apocalypse is happening at the moment. The US is another area where if you look at drought maps from two years ago they were worse than you have ever seen before in your life—the worst on record. So there are various areas with huge pressures on them. The other areas where there are big pressures would be India and China where there is again huge population pressures.
Professor Powlson
If I can add to that, you have different pressures. So, for example, in sub-Saharan Africa I have been involved in reviewing some work from there and you have the situation of soils that have had very low inputs; they are infertile for all sorts of historical but also management reasons and they are under enormous pressures from climate. Just because it is hot and dry erosion happens easily, but you then also have to combine that with social and governance issues. You have very small farmers who cannot afford to buy things, so things like micro-credit come in, so that there are interactions there. Whereas in other places like China where I shall be in a few days’ time, you have rather different situations where agriculture has increased its production enormously over several decades but at an environmental expense, because things like pesticides and fertiliser use, which I think are sensible, have gone up to ridiculous levels in places like that, so that has impacts as well. There is a whole plethora of issues in different places.
Chair
Thank you very much. What can we do to ensure that the soil is resilient and to minimise the effects that we heard about in terms of the impact on climate change? One or two things that you would suggest? Professor Hallett?
Professor Hallett
The simple one is organic matter, so that was raised by the previous group and also last week as well. Organic matter potentially is the ability to sequester carbon from the atmosphere, but that is just one aspect of it. It is basically the building block of the soil and what makes it different from rock, basically. It is something that gives it stability; it will hold on to more water, and any policy put in place to boost up the organic matter in the soil is going to have positive implications both to farm incomes and also to resilience to environmental threats.
Professor Powlson
I fully agree with that. There is an important issue about monitoring, and I think John Krebs referred to this earlier: if we do not measure things to do with soil over time you do not know whether they are getting better or worse, other than in an anecdotal way. The problem is that with organic matter content, which is measured as organic carbon, the total amount changes pretty slowly. I have been working at Rothamsted for many years and we have long-term experiments that have gone on for 170-something years, and so fortunately we, and a few other places around the country and around the world, have long-term data. This is fairly rare, but we know from that that things like organic matter content change slowly. You are looking at decades, really. Now, that means that if you are monitoring by only measuring that it is not very sensitive. You will not know if things are getting better or worse. There are fractions within that total that we know about and I will not bore you with the details, but soil scientists know a lot about these. There are certain fractions that you can identify chemically or physically and there are biological groups within the soil that change more quickly and can give you a bit of an early warning, or you can look at ratios of these different things to total organic carbon, and where they are different from what is expected and normal that can tell you if things are getting better or worse. I would be very keen, as Lord Krebs said, to see a monitoring scheme particularly connected with organic matter but the other things as well. It is not rocket science, as Paul said. Soil scientists know a lot about these things, and with some work and a bit of discussion we could sort something out. You could have a range, you could have the Rolls-Royce end where you measure lots of things but might be too expensive and impractical, or you could have the very simple end, but somewhere in between this can be done. This is not easy. We are dealing with a difficult material, but it is a tractable issue, I would say.
Chair
I remember my visit to Rothamsted looking at the seeds that you had collected over 150 years including through two World Wars, so the commitment to scientific knowledge went on even when there were no glass jars to store things in.
Rebecca Pow
While you said the organic matter changes very slowly, of course we have whole areas in the UK where we have massive soil erosion where there is hardly any organic matter at all, so surely that is a no-brainer in that we have to do something about it, and that is not even difficult to measure because it would not take you very long to come to the conclusion that there is none, or there is very little. Your monitoring is not going to help those areas. That is already destroyed and what do we do there is the crucial thing?
Professor Powlson
Erosion is a special case, and terribly important. In this country its focus is in particular areas, but it is a particular thing. If you are monitoring organic matter content that has huge implications for many properties of soils other than direct erosion. With erosion we already know the risk factors. The ways to combat them may not be put into practice because again it is back to the point that was discussed in the last session, I think, that farmers, who are increasingly highly intelligent, well-educated business people, are driven by short-term economics. The practices that might be sensible in the long-run may not be economic in the short-run, so people may end up doing or not doing things that would be sensible.
Rebecca Pow
Those eroded areas are not to do with wind and things here like they are in the Sahara. They are to do with the type of cropping that the farmers are doing, largely, in the east?
Professor Powlson
Yes, in part. Okay, if you are on a slope you are more likely to erode, whatever you do. If you kept the soil under grass and it is not over-grazed you are unlikely to erode. If it is over-grazed you will get erosion. Other people know much more about that than I do. Any time that you have soil that is bare with nothing growing on it between crops, or big spaces between the plants, like in the situation of maize, all of those factors are likely to increase the likelihood of erosion, particularly under climate change where it is expected that there are likely to be rather more extreme events, such as rainfall. We know quite a lot about erosion. What we do not do really is put into practice the things that we know to slow it down.
Mr Peter Lilley
I must declare an interest, as Rothamsted sits in my constituency.
Chair
Have you seen the seeds?
Mr Peter Lilley
Yes. Can sequestration of carbon in soil play a significant role in reducing carbon emissions?
Professor Powlson
A bit. I declare an interest here. I think I can claim to be one of the people way back in the late 1980s, and certainly through the 1990s, who pushed this idea quite a lot together with other colleagues. Perhaps we got a bit overexcited at the time and some of us have scaled down what we might have said 20-odd years ago. Some of my colleagues still, I think, push a bit too hard on this. The fact is that the organic matter in the world’s soils, put it like that, your country soils, is a very large quantity. It contains about twice the amount of the carbon in the CO2 in the atmosphere. There is much more in the ocean, but that is another matter. You have a very big stock there, and this is where words become confusing. I like to use the word “stock” of carbon. A sink, an active sink, is where a lot of carbon is going into something. With a big stock you have inputs and outputs but that stock might remain constant. For example, if you start a new forest now, you have a bare bit of land and you grow some trees right now from seedlings these will be taking up carbon in the trees; they will be putting carbon through their roots and letting it fall into the soil. That area will certainly be a sink for carbon, so it will be sequestering carbon that would otherwise have been in the atmosphere, quite clear. Because you have this big stock in the world soils already, it is both an opportunity and a threat. It is a threat because you might lose some of that stock, and so deforestation, draining of peat soils have been talked about. These are all things that lead to release of carbon from this big stock. I now put more priority in a sense of looking after those places where we have big stocks. Don’t drain peat, absolutely minimise deforestation. A mad thing in my view, not in this country but it is a relevant thing, is clearance of semi-natural vegetation on peat soils in South-East Asia to grow more palm oil some of which goes to make biodiesel. A lot goes into food things as well. This is releasing carbon because you are draining the peat. It is total madness, in my view. You have to be very careful to preserve and keep those places where you already have big stocks. Where your stock is low, such as in long-term arable soils, you do have some potential to increase that stock, so doing that can indeed contribute to some extent to slowing climate change by locking up carbon that would otherwise be in the atmosphere, but they are not as big amounts as I think some people claim. It all goes in the right direction, so we should do it, but there are some of my colleagues worldwide who I think use overoptimistic numbers for the quantity of carbon that can be locked up in that way.
Professor Hallett
I will add on to where David ended off. Regardless of whether or not it is locking up carbon in an arable system, it is improving the soil somehow, so there is a benefit there in improving the soil. The other thing is carbon dioxide is just one greenhouse gas. Nitrous oxide is far more potent from arable systems, and if you have better structured soil that does not become anaerobic so often you are going to get less nitrogen loss to the environment through nitrous oxide. You are going to have to apply less fertiliser to the land and basically it is a win-win.
Chair
Is that nitrogen coming out just from that fertiliser, the nitrous oxide?
Professor Hallett
There are lots of nitrogen sources within soil, but a large proportion will be the inorganic fertiliser that is added on or the organic matter that is added on.
Professor Powlson
Or from manure.
Chair
Thank you.
Mr Peter Lilley
How significant could no-till agriculture be in reducing greenhouse gas emissions?
Professor Powlson
I would say a bit. Again, I have published papers that make the argument that no-till does not sequester as much carbon as some people claim—often I think because their methodology of measurement is not right—but it does sequester some. So it is generally a good thing from that point of view. The other thing that no-till does, because you are not mixing up the soil first of all it almost certainly will decrease erosion risk, but it does concentrate the organic carbon near the soil surface. That is a very good thing because it gives you better soil quality near the surface. That is good for emerging seedlings and it is good for water infiltration as well. No-till has some part to play, not as much as is sometimes claimed—it is not a panacea, it is not going to save the planet—but it does a bit and it has many other benefits in most but not all situations, but weed control is a challenge, which Peter Melchett talked about.
Professor Hallett
I would just add it probably depends where as well. So in the US mid-west or something, no-till probably is a very good practice to put into place. In the UK the evidence base really is not there, so in monitoring of greenhouse gases from no-till versus ploughed plots in Scotland the trends were all over the place. It is very difficult to predict which system was better than the other.
Professor Powlson
In some cases no-till gives you more nitrous oxide.
Chair
Sorry, Professor Hallett, can I just clarify? Did you say that in the US there is an evidence base for it?
Professor Hallett
The evidence base is much stronger because of that.
Chair
In the mid-west.
Professor Hallett
But they have much lower yields than you get in the UK.
Mr Peter Lilley
Lower?
Professor Hallett
Yes.
Chair
Lower, yes. Is that part of the trade-off?
Professor Hallett
No, it is the farming system is you put lower inputs into the system because you get lower outputs out of it so financially you want to not spend much money on your farming practice.
Mr Peter Lilley
I am not sure if it is your sphere, Professor, but last time I was at Rothamsted your colleagues were taking about potentially increasing the yields of grain anyway. My figures are probably wrong but, from memory, 14 tonnes per hectare to New Zealand levels of 20 tonnes per hectare. We just heard from the previous speakers that yields are declining, which was not what I was told.
Professor Powlson
It is a bit more complicated than that. It is not my field, I am not a plant scientist, but in fact we have had some very high yields recently in our long-term experiments at Rothamsted and also there are situations in this country where again very high yields have been obtained. A farmer in Lincolnshire last year had a world record for wheat yields of 15 point something tonnes per hectare and I think he might have had one for rape as well. So, it can be done. To be fair his inputs are very high as well, which rather worries me. There are cases where very high yields are obtained. Yields in this country have been generally stagnant; I do not think you can generally say that they have been going down—they have been stagnant. They increased a lot in the past but they have been stagnating and indeed at Rothamsted we have had discussions about why this should be. Getting yields up in the past is a combination of plant breeding, better varieties, input and general management and these have all had their effects, but in the last 10 to 20 years the average yields in this country have been rather stagnant. So, within that you will find some places where soils have degraded and they have gone down but then a few cases where a world record holder is doing very well.
Peter Aldous
Would that be down, do you think, to a change in outlook in the common agricultural policy from yield food maximisation to environmental management?
Professor Powlson
I do not know is the answer to that. I am not going to waffle about it because I do not know the answer.
Rebecca Pow
Just very quickly on the point about high yields in your experiments at Rothamsted: when you are getting those high yields are you also advocating good soil management practice to get those high yields or are they high yields because of GM modification and extra inputs?
Professor Powlson
Not GM modification because that is not legal apart from doing specific experiments.
Rebecca Pow
Better plants science. Are you giving advice about the soils? Are they high yields with good soils or are you giving the opposite advice?
Professor Powlson
I hope we are not giving contradictory advice. We are where we are on the soil that we have. We do work with people on other soil types, very contrasting ones. Our soil happens to be really quite a resilient one just by chance. On our very long-term experiments we get high yields with a treatment that has had very large farmyard manure applications over many years and a very high organic matter content—unrealistically large as a practical input. We also get high yields on treatment that has had chemical fertilisers over many years. In fact the very best yields have been with manure plus some extra fertiliser so you can achieve high yields in a number of different ways it would be fair to say.
Chair
Thank you very much. Have you anything to add, Professor Hallett, before we move on?
Professor Hallett
No, not to that.
John Mc Nally
You mentioned earlier that soil organic carbon has decreased over the last 30 years in arable and peat soils. How worrying a trend is this for you?
Professor Hallett
I am not convinced the evidence is there that it has decreased but it has definitely in arable systems decreased in some areas and there was probably a worrying trend even before 30 years ago in terms of the amount of organic matter in the soils. Just to go back to what I said earlier to boost that up is going to have positive impacts in terms of soil quality.
Professor Powlson
There are a number of bits of data on that. Because we do not have in this country really systematic and probably routine monitoring, the database is not good. The countryside survey is one source of data. One I am more familiar with is some work that was done called the national soils inventory run by the Soil Survey Group as they were at Cranfield University. It was a joint bit of work between them, Rothamsted and ADAS and there was a survey of soils on a grid all across the country where many things were measured in around the early 1970s. That was partly repeated about 20 years later in the early 1990s. So, you can look at a trend. You can look at two time points—not nearly good enough, but it is something. Some work published from that on soil carbon showed—my interpretation of the data is a little bit different from the authors’ interpretation—that the soils that were very high in organic carbon had indeed declined over that period and peat soils were a special case of that but I think there were other high organic matter grassland soils, some of which had been overgrazed during that period, causing erosion and degradation. Then you have the mid-range organic carbon soils that had also declined in organic carbon over that period and part of that I am sure is because of the decline in what we would call lay arable farming—several years of pasture, several years of arable. Partly because of just economic pressures but also because of the impact of foot and mouth and BSE some farmers going out of animals so they did not need grass anymore, unfortunately. But a little counter to that was the soils that were already pretty low organic carbon level in the 1970s, because they had been arable for a long time had increased a little bit in soil carbon over that 20 years and my interpretation of that is bigger yields, better varieties and so on, and also straw incorporation because the ban on straw burning came in during that period. So, slightly counter-intuitively I completely agree that many soils have gone down in organic matter but slightly counter-intuitively some that you might say had been the worst have become a bit better over that period according to that data set.
Chair
It is beginning to sound complicated.
John Mc Nally
It seems there are contradictions going on here with the different levels and the deterioration of the levels. I do not know if I am any clearer than I was five minutes ago.
Chair
That is the purpose of this inquiry.
Professor Powlson
Some that were good got worse.
John Mc Nally
I am aware of that.
Professor Powlson
Some that were good got worse. The ones that were the worst got a wee bit better.
John Mc Nally
A wee bit better, so the deterioration is not that too concerning?
Professor Powlson
It is concerning because we need our soils to be in the best possible physical and biological condition not only for agricultural purposes, although certainly for that, but because of all the ecosystem services, to use the nerdy term, that we get from soils to do with cycling of water, habitat for organisms and so on. Those things as well as agricultural productivity will almost always be better if soils have a bit more organic matter and therefore better structure. So, it is concerning but there are things we can do about it, albeit not always easy to do but we know a bit about what can be done.
Peter Aldous
We have very variable soils across this country. Does that make it difficult, do you think, to develop policy at a national level?
Professor Hallett
Yes, it does. You can be a bad farmer on very good soil and come across much better than a good farmer on very poor soil if you put policies in place, so it is difficult to implement that. It is also difficult with the complexity to work out what targets you should be aiming for. If you were, let us say, aiming for a 20% increase in carbon it could be very easy in some areas, much more difficult in other areas. So it adds complexity to it definitely.
Peter Aldous
Do you feel there are lessons to be learned from other policy areas as to how one might address that? I am thinking such as in water management.
Professor Hallett
Definitely. There would also be benefits from looking at how other countries are looking at soil monitoring and soil protection strategies as well. For instance, many Scandinavian countries have quite detailed policies in place. Scotland is moving toward that direction as well, so there is a lot to be learned.
Peter Aldous
Just talking about Scandinavian and Scottish countries, perhaps they do not have the natural advantages that parts of England might have had for a long time and therefore they have been more prudent in the way they have managed their soils.
Professor Hallett
In terms of my own research area, which is soil compaction, then yes, definitely, because their soils are incredibly vulnerable to soil compaction so they spend a lot of research in that area and they put a lot into education of farmers and also implementation of policies to try to reduce that. So, in Denmark soil compaction is viewed as one of their greatest environmental threats. You are completely right with that statement that it has been more obvious to them. They have been working in a more stressed system.
Peter Aldous
When we look at areas like the United States, Canada and the Ukraine where we are looking at a completely different type of agriculture, what do they do, if anything?
Professor Powlson
It is a different type of agriculture. All those places are all pretty large scale agriculture, larger scale than ours but big rather than sub-Saharan Africa scale. Again I think there is a mixture of things there. I am sure in the US there isn’t legislation as such but there is very strong advisory type work going on through the Soil Conservation Service, part of the USDA, for example. There are also a lot of farmer-led activities, as there are in this country as well now. For example, zero tillage has been mentioned. I think this has a lot of benefits, benefit for soil carbon in terms of total quantity. It is smaller than claimed but it concentrates near the surface so it is good. In this country there are some highly innovative farmers, one of which is near Rothamsted in Mr Lilley’s constituency, Ian Pigott—all the best people clearly—who have decided that their soils are deteriorating and they need to do something about it. These farmers are going to a zero tillage system using new equipment that has only recently become available. They are also moving to more spring-sown crops rather than autumn-sown ones—I will come back to that in a moment—and then having cover crops during the winter. Cover crops are sometimes proposed as a way of mopping up nitrate from a water quality point of view and nitrate vulnerable zone legislation has this in it but they are growing these simply as a way of getting some more organic matter and plant material to go in the soil. So, there are some farmers who are taking initiatives and grabbing hold of new equipment as it becomes available and so on. I think there are issues there because having more spring-sown crops can be economic for the farmer. The yield is lower but the input costs are lower. But on a world basis the total grain production will be lower so nothing is quite straightforward.
Chair
Thank you very much. We are going to move to the next question. [Interruption.]
Peter Heaton-Jones
Thank you very much indeed. Professor Bardgett, welcome, by the way. You have come in at a particular point. We will let you—
Chair
We have done an inquiry into flooding and resilience of the transport network.
Peter Heaton-Jones
How very appropriate. We will let you catch your breath before we launch straight into your questions. Let me ask Professors Powlson and Hallett, thinking about the way we can encourage landowners—incentivise them perhaps is a better word—to take measures to ensure that soil protection is pretty much high on their agenda. Are we clever enough at that? Do we need to do more to incentivise landowners on soil protection, Professor Hallett?
Professor Hallett
Definitely you have to incentivise them more. The levy boards of the HDB in Britain put a lot of money into trying to look at better soil management practices so there are a lot of programmes open at the moment and that is basically money paid to the levy for generating the crop gets put back into both research and also education on how to manage soils. Likewise the various government agencies do the same thing. Groups like the Soil Association also push towards that. But there has never been enough education and it is something where I think both through education and also through specific policies you may be able to encourage farmers to perform better soil management. And there are a quite a few different constraints that they are working against.
Peter Heaton-Jones
Before I come to you, Professor Powlson, how might farmers be encouraged, to use that phrase?
Professor Hallett
On organic matter, giving them a source of organic matter is probably the best way, so whether it be encouragement of residue incorporation rather than selling it off to produce fuel or livestock feed or whatever is one aspect. Providing them with new plant varieties that may be better in terms of returning carbon to soils, generating anaerobic digested or composting on farm is another possible approach that could be used. Also municipal sources of compost or other organic sources so there are a lot of potential areas there. There is encouragement off putting in break crops, using education about cover crops as well, so there are various mechanisms that are possible.
Professor Powlson
Again, recycling of waste better would be one way to go. From a policy perspective, I would love to see some way in which there were payments in a way for good practices. For example, organic products can command a higher price—not always that much higher, but that tends to be a small market for people who can afford that or make those choices. There are other things. For example, there is an organisation called LEAF, which stands for Linking Environment and Farming, doing an absolutely excellent job of working with farmers and so on and indeed bringing farmers and consumers together. They monitor farms and give accreditation for good practices and so on but is nobody pays more for that, so that is one thing. On the positive side the organisation in England, Natural England, do quite a lot of good things. They call it catchment-sensitive farming, which must be funded directly or indirectly through Defra I think. They do some quite useful work with farmers on catchments; the clue is in the name. So, there are some good things going on in what you might say in an educational sense but being sensible, not experts telling farmers what to do but having proper involvement with farmers.
Peter Heaton-Jones
I am interested in this grey area between education and incentive. Are we saying that there are landowners who generally speaking know full well what needs to be done but frankly need some incentive to do it, or are we saying they just do not know what needs to be done in the first place?
Professor Powlson
I am sure there will be the whole range.
Peter Heaton-Jones
Generally is it possible to say which direction do you think we should go in? Is it purely education or do we assume they know but they are not doing it and they need some incentive to do it?
Professor Powlson
I think for larger arable farmers I might go to your second option, which takes me back to the short-term economics versus long-term good practice, but I could be wrong.
Professor Bardgett
Just to add, I agree with everything my colleagues said and I think waste management is absolutely essential to this in terms of recycling waste on farms but also bringing other waste in. In relation to your other question my impression is it is really, as David said, a combination of those and in some situations there are probably already farmers who are very knowledgeable about what needs to be done to maintain their soils but I suspect in other places there is quite a lack of knowledge about it not through any other reason that they have not just had that information or it has been exposed to them. I think there needs to be a combination but those incentives probably need to be targeted at particular areas where something can be done to improve soil fertility but also there could be incentives that are more about protection. To me, it is really three measures. There is a need to protect what we already have in terms of natural systems or semi-natural systems. There is also the need to prevent degradation of soils that is ongoing through different incentives and measures, but also I would say there needs to be more incentive to restore soils as well because there are an awful lot of soils particularly in urban areas and so on that could be restored. Soils are incredibly resilient and I think there is capacity to restore them through incentives as well. Just one very final thing I would add to make up for my absence: I do think on a positive note that scientists are also working more with farmers from the onset of doing experiments and that kind of thing needs to happen more. When we design our experiments we need to work with the landowners, the land managers to ensure that the science we do is relevant and can be fed into practice.
Chair
Thank you very much indeed. Did you have a follow-up?
Peter Heaton-Jones
I was going to seek your guidance. Do you want me to go back to what was going to be our original first question to Professor Bardgett?
Chair
Yes, let us just quickly do that, very quickly.
Peter Heaton-Jones
It feeds in rather well as we have been talking about the need for education. If you widen that out to the thought of public awareness, so not just among landowners or farmers but the public in general—we did touch upon this with Professor Hallett earlier on—you say, Professor Bardgett, in your written evidence and I quote, “There is a need for greater awareness among society of the vital importance of soil for human lives”. How do we do that?
Professor Bardgett
I believe that very strongly. As a soil scientist it is a very common thing that you encounter. When you tell people what you do, they are slightly confused about its importance, but when you explain it to them they can see the relevance and to me it is really about education in schools. I am not aware if schools deal with soils in any way other than perhaps in A levels when they may be looking at soil profiles. From an early age, children should be exposed to the importance of soils. There needs to be more education among the general public. It is quite clear that lots of people live in cities and more people are turning to growing their own food, but there seems to be an awful lack of knowledge about how best to manage soils—how to deal with contaminants in soils to prevent contamination of food and so on. So, I think it is at all levels and also in terms of agriculture through the mechanisms we were talking before about enhancing knowledge and awareness in that sense.
Peter Heaton-Jones
As a Committee, we should be looking at how we can help that and would that be a Government project? Would that be something that would have to be led at a Government level or are there other ways we could do that?
Professor Bardgett
I think so. At the very core, looking at the national curriculum for teaching and getting it embedded in there. I am not suggesting you have A levels on soil science but I think soil should be embedded within teaching from an early age in terms of its importance generally to mankind and to local communities.
Peter Heaton-Jones
One brief follow-up: what about those of us who have long since left school, though? You have a great many people who are not taking GCSEs or A levels who need to know this stuff. How do we get to average Joe public?
Professor Bardgett
Again, the Government can do an awful lot. If you look back to the Second World War in the Dig for Victory campaign there were major educational programmes for the general public on how to grow food in often terrible soil conditions and we were enormously successful as a nation in producing food at that time. Similarly in America there were education programmes within local communities about how to manage the soil to produce crops for food production. The evidence is during those times those countries, Britain and also America produced an enormous amount of food through the local communities. A lot of that was driven by public awareness and also education—local education on how to deal with the soil to grow crops.
Peter Heaton-Jones
So, a bit of wartime propaganda—“your soil needs you”?
Professor Bardgett
Perhaps in a different style but I think local educational programmes on how to deal with soils.
Rebecca Pow
Just following up on that note, the gardening fraternity have already got it about soils and it is odd we have not transferred that over so we could learn lessons from what you are saying. Also just on that note when students go to study agriculture do they do soil science still? We used to back in the day.
Professor Bardgett
Yes, they almost certainly do and I think most degrees in ecology, geography will have an element of soil science within them. But very often it is embedded within another course so it might be a—
Rebecca Pow
I believe you cannot do a soil science degree now anymore or anything like that, can you? Is that right?
Professor Hallett
You can at the University of Aberdeen.
Professor Bardgett
But there are not many.
Rebecca Pow
That is important. On the same note, because plants and the types of plants we grow are so important in this, I believe there are not any botany courses either.
Professor Bardgett
In Manchester we have a degree in plant science.
Rebecca Pow
I thought you could not study botany anywhere.
Professor Bardgett
I am not aware of—
Rebecca Pow
I think that is another issue to raise in this whole subject of science and who studies what and trying to encourage anything. Would you agree?
Professor Bardgett
I agree, but I also think that, in university education, the best way to get students interested in soils is not necessarily through a course on soils. It is more through a course on climate mitigation or food security. You captivate them by the bigger issues and then you bring in the educational element of soils and it is gripping them in the same way you might grip them in terms of teaching them about cancer or something.
Professor Powlson
Can I add to that? I am a visiting professor at the University of Reading that is one of the places you used to be able to do a BSc in soil science. You cannot do that anymore there. The soil science group is embedded within a larger school but my colleagues there say on the positive side they are giving some soil science courses to more people than ever before even though nobody comes out with BSc in soil science.
Rebecca Pow
Thank you very much. To get on to the real emphasis of my question, we have touched a little bit about monitoring schemes, but in a nutshell—perhaps we can start with Professor Hallett—should we have a monitoring scheme for soil health. If so, what would you do and how would you do it?
Professor Hallett
The answer to the first part is yes, definitely. Then how should we do it? I would say that it would be better to have multiple people input into what needs to be measured but definitely carbon has to be measured and it is not just weighing how much carbon is in the soil. You have to go down to quite a deep depth and work out how much there is in the whole entire profile. That is not categorised that well. I know a study that was done in Scotland predicted that it would be estimated about £400,000 to sample it more effectively, not often but more effectively, just in our country. So, to do it UK-wide would be quite a bit more than that but that is only one measure. So, there are a lot of other properties related to the fertility of soil, the biology that is in it, how it behaves physically, which is also quite poorly understood so when we look at things such as water storage during drought, flood risk alleviation or whatever else, the way the soil changes over time, the actual flow properties within the soil again are not that well characterised around the UK. So, there are a lot of very simple measurements that can be put in place we could all agree on probably in the next two minutes and then there are other more sophisticated measurements that are needed as well and it is all going to be dictated by how much it costs.
Rebecca Pow
You specialise in soil physics so are those things you included in that answer or are there more things related to your specialism that we should be including?
Professor Hallett
In terms of what was raised by the previous group that soil compaction was the big issue, I raised the comment about Scandinavia before. Compared to the Scandinavia countries, our understanding of soil compaction is quite poor in the UK. The tests are fairly easy to work out if a soil is compacted or not. There is much more work you could do to look at how to alleviate the problem and how to get around it. In terms of water flow it is not that well characterised spatially. It is done at very big scales but what is happening down at field level where a farmer has control over it is not that well understood. It all depends on the spatial scale and how that integrates together.
Rebecca Pow
But it is possible?
Professor Hallett
It is possible, yes.
Professor Powlson
I would agree with all those things. Indeed we should have a national monitoring scheme so we know which direction things are going. Otherwise we are talking in the dark. Certainly soil carbon must be part of that as I said earlier. That changes very slowly so you really want some things that show you trends more quickly and there are fractions within or associated with the total, I will not bore you with the details, but a group of soil scientists could agree on some of those, which would be useful. There are groups of microbes or soil fauna that could be included in that and there are ways of measuring them. This would tell you a lot. Earthworms even tell you an awful lot about what is happening and indeed there is a suite of physical properties, again we can debate the details but this could be done.
Rebecca Pow
Professor Bardgett, in your written evidence you specifically mentioned monitoring soil health. Have you anything to add there?
Professor Bardgett
I agree with everything that has been said. It should be done without question in my mind and, again, we can debate the value of different methods but as a community we could very easily come up with a set of robust measures that could be routinely measured and some of them have been mentioned: organic matter content, carbon would be an obvious one, aggregate stability, compaction. I think the point Professor Powlson made about more rapid assessments, that is where the biological measures come in and there are some measures and work is being done to identify and rank some of those measures. The beauty of those is they can tell you how soils are changing quickly whereas, as Professor Powlson said, the other measures take several years so it is almost like an early warning sign perhaps.
Rebecca Pow
If we as a Committee put this forward as an idea about soil monitoring of course the farmers are going to just heave another sigh and say that is another load of bureaucracy and all the rest of it. How would it operate and who would pay for it because I can see this could be costly?
Professor Hallett
We are doing a monitoring programme across four catchments in Scotland at the moment where we have to go out to 120 different farms and get access to the land. Fortunately the person who is doing the work is very personable so she can interact with the farmers very well, but they are all really keen to have her on the land. She is looking at soil physical degradation and we are giving them information back out of it and that is the same thing. We say we are going in to do monitoring but we are going to provide you with information and it is going to help your farm—
Rebecca Pow
Are they paying you? Are they paying for it?
Professor Hallett
No, this is paid by the Scottish Government.
Rebecca Pow
That is the sticking point. I know lots of farmers already test their soil, is that just for alkalinity and that sort of thing? I declare an interest: my parents are farmers. They say they already do quite a lot of soil testing.
Professor Powlson
They do indeed, so most farmers, probably the vast majority, would have their soils tested. They would be particularly looking at nutrient availability to guide them as to how much fertiliser they need and that sort of thing. They would also in certain cases be checking on acidity, soil pH, whether to put on more lime or not. Organic matter content is usually a routine thing. If you are paying a lab to do this for you organic matter will be in there but not fractions or things that will tell you about rapid changes, and almost rarely any physical measurements.
Rebecca Pow
So this would be in addition? It really would help.
Professor Powlson
There are schemes. For example there is a scheme set up by Cornell University in the United States. I think it is called the Cornell soil quality or soil health scheme. It is not a monitoring scheme. Farmers pay $90 a field and there is a cheaper version I am told at $60 that includes all the things we have talked about. There is a lot of knowledge of all the things that can be measured and as both my colleagues have said with a bit of effort by the soil science community we could pick a sensible suite, but again there would be a cost involved.
Chair
We look forward to the launch of your programme. There is a final question from Mr Mc Nally.
John Mc Nally
I should have declared an interest here because I am a member of the Community Green Initiative in my own local area. I want to go back to your point on education. For some time now the Community Green Initiative has engaged with the local schools. They are engaged with the local YMCA where they go out and plant their own food. They grow their own plants themselves so the children, bit by bit through that, are managing to gain an understanding, quite a good comprehensive understanding of how the soil works. To carry that on further there is a huge demand on the soil growing your own locally produces food so you have all these competing interests. Without a doubt you have that. But to move on to my question, Defra is currently preparing a 25-year plan for the environment and I will just cut to the chase. Do you think there are lessons that can be learnt from the way the Scottish Government is trying to integrate the soils policy framework and including the Welsh approach on their soil quality, their indicators, is England playing catch-up on Scotland and Wales? Unfortunately not on the rugby field, but there you go.
Professor Powlson
If I can come in, I think that is right. It seems to me the evidence is, speaking from an English perspective, that the Scottish and Welsh devolved authorities have done a better job of at least trying to take the quality of soil seriously within a policy framework than has been the case in Defra. Defra, as I said at the beginning, has produced nice documents in the past, but I do not see any evidence of much happening as a result of them.
Chair
Have you anything to add, Professor Bardgett?
Professor Bardgett
No.
Chair
Professor Hallett? You are going to start charging those farmers for their field testing.
Professor Hallett
This was Defra funded, very similar monitoring in the south-east of England.
Chair
So it is not just in Scotland. Professor Bardgett, did you want to come in? We are very keen to hear from you given that you have had a full 18 minutes with us.
Professor Bardgett
Just one very quick thing. I think about the monitoring to me there are also two issues there. There is monitoring that is of use at a farm level and soil kits, education programmes in terms of how to best use that information would be enormously valuable at a farm level in some places. But it is also about natural capital and some of the monitoring schemes are really about monitoring soils change over time and how our soils are changing and their contribution to climate mitigation, nutrient loads and so on. So, for that I guess that to me is more of a government responsibility really.
Chair
Thank you very much. Can we conclude with a very quick-fire question? It is not often we get three soil health experts here. For those of us who do not have farms, do not live on farms and have very small city gardens, what one thing can we do to improve the quality of our soil? I am going to take each of you in turn, Professor Hallett. In a garden the size of this table.
Professor Hallett
We are all going to say the same thing: add carbon.
Chair
But how? What sort of carbon? How do I add carbon? When I go home tonight what carbon do I add? Where does the carbon come from?
Professor Hallett
You have me stumped.
Chair
Food waste, rotting food waste?
Professor Hallett
It depends where you are and what you are growing; it might be trees, it might be crops, so it is carbon is what I am going to say.
Professor Powlson
I agree with that. It could be from plant residues. It could be from food waste, all of those things, but also keep an eye on the acidity. In some places certain grassland soils are becoming more acid because lime costs money, so farmers have in fact saved money on that and that is an issue in this country.
Professor Bardgett
I could give you a whole list but giving you just one I would agree entirely. It is really down to waste management and recycling of waste. The analogy to me quite simply is if you use something and do not refuel it it is going to go into a bad state of affairs.
Rebecca Pow
Does that include human waste? Have you covered that?
Chair
Five seconds.
Professor Bardgett
Around a lot of cities in the 1800s there were night soil men, around where I live, around Manchester.
Chair
We will see whether that makes it into the final report; I am sorry to put that on you. Thank you very much indeed. Particularly Professor Bardgett, thanks for making the journey. I am sorry if for you the sitting was not long. Oral evidence: Soil health, HC 653 7