Some progress on the maize front

Avid readers of my blog will know I have been campaigning about the detrimental impacts of maize cultivation in Devon, in particular its implication in local flooding – see here for blogs on that topic. Well, some progress appears to have been made. Last week the Department of Energy and Climate Change (DECC) published a consultation document entitled “Review of support for Anaerobic Digestion (AD) and micro-Combined Heat and Power under the Feed-in Tariffs scheme” – you can download it and read it here. Be warned – it is mighty hard work …. Much of the document relates to proposals to reduce the ‘Feed in tariff’ payments but part of it relates to maize.


The document states “It is also Government policy that the primary purpose of agricultural land should be for growing food. Data published at the end of 2015 suggests maize is increasingly being grown for AD installations.”. This conclusion mirrors exactly what I have been saying!

As a result the following two options have been put forward:-

  • Option 1 – Restrict FITs payments to electricity generated from biogas derived only from wastes and residues
    If implemented, only electricity generated from biogas derived from wastes and residues will be eligible for generation and export tariff payments.
  • Option 2 – Limit FITs payments in relation to electricity generated from biogas not derived from wastes and residues to 50% of the total biogas yield
    If implemented, electricity generated from biogas derived from wastes and residues will be eligible for generation and export tariff payments. Electricity generated from biogas derived from other feedstocks will be eligible for generation and export tariff payments but only up to a maximum proportion of 50% of the total biogas yield produced in that quarter.
    The maximum is set at 50% because crops such as maize tend to have a higher biogas yield compared to typical farm waste feedstocks such as manures, resulting in a relatively low ratio of crop to waste per tonne of feedstock.

Option 2 is currently the preferred option because it provides for payments for electricity generated from biogas with high carbon abatement costs, but offsets some of the risks associated with investments and feedstock support from only using waste and residues.

What this means is that DECC intend to cut the subsidy paid to maize farmers by probably 50% (i.e. option 2) in an attempt to discourage them from growing maize as a source of biogas in Anaerobic Digestion (AD) plants. The question is therefore, will a 50% cut be enough to change land use? Will this mean that the amount of maize grown in Devon will reduce and therefore will the amount of flooding experienced by local communities reduce?

This is undoubtedly progress and is to be welcomed.

Maize field mud

DECC must have been privy to the report of the Environmental Audit Committee on Soil Health which was published today because there is much mention in that report of this very topic. You can download that report from here. The problems caused by maize are mentioned on pages 26-28 and pages 34 and 37. The recommendation of the EAC is that subsidies should be removed from maize cultivation when it is grown for AD biogas production.

The EAC took evidence from a number of specialists in the field (who are quoted in the report) including the Soil Association, Rothamstead Research, the Committee on Climate Change and the National Trust, all spoke about the problems related to maize cultivation, soil health and flooding.

However this single recommendation relating to maize and AD plants will not be enough on its own to safeguard soils and reduce flooding risk. Maize cultivation has grown from 8000 hectares in the UK in 1973 to 183,000 hectares in 2014. In Devon maize cultivation has rocketed 89% between 2000 and 2013. The vast majority (80%+) of maize is grown as feed stock for cattle and not for AD plants. The DECC proposals will therefore only apply to 20% of the maize grown in the UK.

Rory Stewart, the DEFRA minister responsible for the other 80% of maize grown in the UK also gave evidence to the EAC Committee and said “maize planted incorrectly, harvested at the wrong time of year or in the wrong climatic conditions can contribute to soil erosion” and “If your maize processes are contributing to soil erosion, that is in breach of your cross-compliance regulations and the RPA can then fine you for doing that.

He then went on to say this “That is really an issue for the Department of Energy and Climate Change. It is predominantly about energy policy, renewable energy policy and the different types of renewable energy policy, but we certainly within the Department are looking closely from our point of view at the costs and benefits of that kind of activity“.

In effect Rory Stewart said that controlling soil degradation and flooding as a result of maize cultivation needed action from DECC regarding subsidy levels. The problem is that 80% of the maize in the UK is regulated via his Department’s cross compliance rules which are clearly not working effectively.

To be generous to Rory Stewart one might say that Government works in a highly choreographed fashion. We are awaiting the publication of the Environment Food and Rural Affairs Committee Report on the recent winter floods (where maize again was much discussed) along with the Government’s report on flooding and DEFRA’s 25 year Environment Plan – all expected this summer. Let’s hope that the impact of the ‘80%’ of maize is covered in those reports and changes are made as a result.

Exton maize

My friend and co-maize campaigner Miles King has also blogged on this topic today – see here. He also kindly alerted me to the DECC consultation which I otherwise would have missed.

Natural Flood Management on Countryfile

Countryfile on Sunday did a couple of films on how to manage the problems associated with the recent floods. The two pieces featured examples from the south west.

You can watch Sunday’s Countryfile by pressing here and viewing on the BBC’s  iPlayer. The first piece is about natural flood management schemes also known as ‘upstream measures’. This section is 7 minutes 32 seconds into the programme.

Nigel Hester - Countryfile
It features the work carried out by the National Trust on its Holnicote Estate in Somerset. This is a picture of Nigel Hester, the NT’s project manager with Tom Heap from Countryfile. It is a widely acclaimed scheme and I am visiting Holnicote next week to meet Nigel and be shown around – I will report back.

The National Trust have also recently published the report on the Holnicote project “From Source to Sea – Natural Flood Management” and you can download it here. The project was funded by DEFRA, the Environment Agency and the NT and involved the University of Exeter, JBA Consulting and Penny Anderson Associates Ltd. It is well worth a read as I am sure it will be a major  building block for much that we will see happen in the future to ‘slow the flow’.

The second part of the Countryfile piece on flooding tackled dredging and focused on the Somerset Levels. That part starts 26 minutes 58 seconds in. Again a very balanced piece and is well worth watching.

Part of the challenge with dealing with floods is to separate fact from fiction, hyperbole and prejudice. There are lots of competing interests when it comes to this topic and I thought Countryfile did a good job in setting this out.



Maize in the news again

I found this article on FG Insights – a farming website – called ‘Is it possible to crow maize responsibly?‘ You can read if here. It is a very fair summary of the issues involved – what was surprising to me was the implied acceptance that most maize wasn’t being grown responsibly.

Screen Shot 2016-02-11 at 22.56.59
This was my response on Twitter to the article

Toby Willison Exec Dir Ops EAThis is a tweet from Toby Willison – he is the Environment Agency’s Executive Director of Operations – good to see the EA taking a stand but I would like to see them getting more proactively involved locally and publicly.

I also came across this piece on the BBC website about a farmer in Somerset “Powered by poo: Somerset farmer enjoys biogas boom” – see here. This is very encouraging – there is a huge growth currently of biogas or anaerobic digestion (AD) plants at the moment – the Government is actively and financially supporting this process under the banner of ‘Energy from Waste’. However most of the new AD plants in my part of the world rely on the contract growing of maize to fuel the plants as there doesn’t appear to be enough waste available. This Somerset farmer shows it can be done and he specifically states that he isn’t going to use maize in his plant as he has enough waste via his dairy herd. Good for him – solving the problem of the disposal of animal waste by producing green power.

The other AD plant I know that runs on waste only is the Langage plant near Plymouth. They recently submitted a planning application to expand the site so I emailed them asking if this meant there would be an expansion to maize growing in the area to supply the enlarged plant. They came back to me immediately and told me they didn’t use maize in their system and only used waste. Good for them too.

The Soil Association have also just published a new report entitled “Seven Ways to Save our Soils” which you can download here. This report isn’t just about maize, it is about soil management generally but is of course very relevant to maize cultivation. Here are the 7 ways:-

  1. Increase the amount of plant and animal matter going back onto fields
  2. Improve soil health monitoring across the UK
  3. Encourage soil organisms – both those that build up soil and those that release nutrients
  4. Cover up bare soil with continuous plant cover
  5. Bring more trees onto farmland
  6. Reduce soil compaction from machinery and livestock
  7. Design crop rotations to improve soil health

If you have published a report like this 40 years ago farmers would have looked at you as if you were mad – it was what they all did routinely – how times have changed.

Maize field mudFinally as a result of the winter storms and their impact on my village – Exton in East Devon I wrote to my local MP Hugo Swire about flooding and the issue of the increased cultivation of maize. My letter to him is below.

27th Jan 16

Dear Mr Swire MP,

I  live in the village of Exton which is in your constituency where I have been a resident for around 3 years. Over that period of time I have been alarmed at the flooding in the village from the Exton brook.
I write a blog and have written a number of pieces where I make the link between the flooding and the proliferation of maize growing in the catchment.
I have also been contacted by some local residents in the Village who have been flooded in Station Road and by a local District Council (Geoff Jung) who had seen my work and was trying to sort out problems for some of his electorate who had recently been flooded for the first time ever in Woodbury Salterton/Raleigh.
I also saw a piece about the flooding of the School in Tipton St John where you were asking for answers. 
I am convinced that the flooding that has taken place recently in East Devon has been in a large part caused by the increase in maize growing  which is tied in with the opening of the 2 Anaerobic Digester biofuel plants on the Sidmouth Road near to the Show Ground.
This is the link to the blog I wrote today regarding the growth of maize growing in Devon
along with a couple of other links to earlier posts.
I think  a consensus is forming now that to tackle flooding we need to work at a catchment level which must include carefully scrutinising land use and land management practices. Maize fields are heavily compacted and are harvested late in the year so they are left bare and vulnerable to runoff in periods of wet weather during the winter.
Maize cultivation in your Constituency is a part of the problem and needs to be carefully looked into to determine whether the location and scale of the activity are compatible with a flood-free existence for the people who live in the villages downstream.
Much of the research into the damaging effects of maize were conducted by the Environment Agency see here
I am wondering whether the Environment Agency discussed this with you when you met them regarding the flooding in Tipton St John  as the photograph I saw showed the bright brown flood water which is so characteristic of the problem?
I find it rather a sobering thought that the flooding problems experienced in East Devon occurred as a result of ‘Yellow Warnings of Rain’, let’s hope we don’t get Amber or Red Rain Warnings.
Yours sincerely,
 Adrian Colston
When he replies I will let you know what he says.
If you are worried about the possibility of flooding where you live as a result of maize you could write to your MP too.

A trip to Holne Moor – cuckoos, scrub and flood prevention

I spent the afternoon yesterday with Kevin Cox, who lives in the Mardle Valley, is an RSPB Council member and heavily involved with Devon Birds. We talked about Devon birds, Devon Birds and the management of Dartmoor’s commons. Kevin has recently purchased part of Holne Moor from South West Water.

Holne 1
Holne Moor overlooking Venford Reservoir.

We went up to Holne Moor to have a look around. A very interesting visit for me. This is the key bird research area I have written about recently – the place where Exeter University’s Professor Charles Tyler, his team of research students and nest finders have been working (The Dartmoor Upland Bird Nest Group) – see here and here. This is the area where some of the key cuckoo research is taking place as well as being an area which supports high population densities of whinchat and meadow pipit.

Holne 4
The moor is grazed and has a swaling programme but does have quite a lot of small trees dotted around the landscape – cuckoos need these small trees so that they can survey the landscape and see where the meadow pipit nests are. On many commons now these dotted isolated trees are absent and new regeneration is now difficult due to the grazing and burning pressure.

The area is also very interesting as it gives a clue as to how natural flood management measures might work on Dartmoor in the future and play a part in ‘slowing in the flow’. South West Water have retained a belt of land around their reservoir at Venford. This area has been fenced off.

Holne 2

In this photograph you can clearly see the fence line – with grazed moorland to the right and the lightly grazed enclosure to the left. You can see that patches of light scrub have developed in the closure.

Holne 3
Here is another view of that enclosure.

These two photographs tell me a couple of things.

Firstly, if Dartmoor was not grazed, scrub and eventually woodland would quickly develop – the George Monbiot re-wilding scenario. Dartmoor is of course as I have said many times before an important historical and cultural landscape and therefore if the re-wilding scenario were to happen across the Dartmoor landscape then most of that would be lost. The landscape of Holne Moor is a good example of this as it has been ‘designated’ as a Premier Archaeological Landscape – see here for further details.

Atlas of Antiquities 1Jeremy Butler in his 5 volume Dartmoor Atlas of Antiquities sets out a detailed catalogue of the archaeological interest.

Atlas of Antiquities 2
The map and accompanying text details the importance of the area from the Bronze Age, through the Mediaeval period to the present.

The challenge for all those involved with the management of such places therefore is getting the balance right between archaeological interests and biodiversity – both of which are of European Importance. I have written about this challenge before and it seems to prove intractably difficult to solve even though all parties are in fact pretty much in the same place – i.e. everyone wants a grazed landscape.

As Kevin Cox said to me on site yesterday (I paraphrase) – the archaeology has survived on here on Holne Moor for thousands of years through the ebb and flow of vegetation and farming cycles, however at the moment there is a biodiversity crisis and we may only have 30 years to save some species such as the cuckoo. Surely there is enough flexibility and goodwill within the system to tweak a few management techniques and thereby work out how to enable the cuckoo (and whinchats, meadow pipits etc) to flourish (e.g. ensure there are perching places and enough food for cuckoos) – the work that the Dartmoor Upland Bird Nest Group are currently researching.

The second thing that the two photos above tell me is how quick and easy theoretically it will be to naturally add regenerating trees and scrub to the landscape in very small but strategic places so that natural flood management schemes can help slow the flow. If enclosures were erected around specific stream valleys the developing scrub would quickly emerge and add ‘hydraulic roughness’. The areas of grazing land lost would be tiny and as long as the Commoners were compensated and not penalised as the current ‘ineligible feature’ nonsense currently would do then surely this too is a win-win for everyone.

I thought yesterday was going to be dominated by Storm Imogen – it certainly seems to have around our coasts but inland it was pretty windy but in my experience was mostly dry and allowed me instead to make a new friend, see a new place and think more about Dartmoor and its management.Holne 5


Politicians go into overdrive about the flooding

The last couple of days has seen a huge amount of political debate about the floods. There is so much happening at the moment that I am still working through a lot of it and digesting it.

Firstly there was a Ministerial Statement by Liz Truss – a full transcript of that debate can be downloaded here. There is a lot in it and it is worth a read. I was pleased to see Liz Truss had said the following.

In the light of recent events, we have commenced a national flood resilience review to ensure that the country can deal with increasingly extreme weather events. The review will look at forecasting and modelling, resilience of key infrastructure and the way we make decisions about flood expenditure. …….  The work of the Natural Capital Committee, to which I have reappointed Dieter Helm as chair, will complement that. It will further develop the catchment-based approach we are now using for our environment planning, including slowing the flow upstream.

This is good and important as there is now a clear understanding in DEFRA that stopping flooding is a multi-faceted issue. It wasn’t that long ago that the debate was solely focusing on dredging and building flood defences.


The Secretary of State refers to the Nature Capital Committee which chaired by Dieter Helm. The NCC is the independent advisory body set up to advise the Government on the sustainable use of England’s natural capital – our forests, rivers, atmosphere, land, wildlife, oceans and other natural assets. They clearly have a role therefore to play in the flooding debate. The chairman Dieter Helm has recently published a paper setting out the issues regarding flooding as he sees them. You can download and read his paper here. Helm sets out the summary of his case as follows.

There are three steps to the required rethink, and these are set out in this brief summary paper. The first is to work out how much flood defence we need, and what it should comprise of. This requires an economic assessment of the catchment systems and their natural capital. The second step is to create a longer term, sustainable asset-based framework and the associated financial basis. At the core are: a balance sheet; an asset register; a regulated asset base; debt finance; and a corporate structure. Third, floods defence needs a proper institutional context. Flood defence needs to be put on a stand-alone basis, allowing the EA to focus on environmental protection, structurally separating out operational, project management, catchment management, regulation and catchment planning functions. The paper brings these three steps together to propose a way forward.

In case you haven’t guessed – he is an economist! I’m not going to comment on his second and third points at this stage as I am still mulling over what it means but in his paper regarding the first step he says:-

Agriculture takes up most of the UK’s landmass, and it is both a major cause of increased flood risks and a major potential means to alleviate these risks. Yet agricultural policies and the associated subsidies pay little or no attention to the flood risk dimensions. Some particular examples include: the much greater exposure to rapid run off from the planting of maize; the soil erosion of such crops; the importance of pasture and grasslands on river margins; the burning and encroachments on heather moorlands; and high stock grazing densities.

The farming practices of the upper reaches of river catchments are especially important in determining flood risk. These are also typically the most highly subsidised types of farming, with the lowest agricultural yields. Thus the costs to outputs of adapting practice are lowest, yet they have the highest benefits in reducing flood risk by holding water. They typically also have the greatest value in natural capital for recreation, leisure and biodiversity.

In the Somerset Levels case, the changing farming practices directly contributed to the silting of the two main rivers, and there were demands for dredging to deal with the consequences. Upstream farming practices have contributed to the more recent flood events too.

This is important stuff – an influential Government appointed figure talking about the importance of land use and farming practices along with the roles they play in exacerbating flooding risks. It seems like only yesterday that saying such things was sacrilegious! It gives credibility to the comments of George Monbiot – see here for example and also my blogs about maize – see here for example.

Exton brook1

Yesterday there was an Opposition Motion on the Flooding led by Labour’s Shadow to Liz Truss Kerry McCarthy. You can download the transcript of that debate here. Again a long and interesting debate with many differing views, but importantly some members from both sides of the House clearly see solutions to the flooding problems lying beyond solely dredging and defences. This is part of what McCarthy had to say:-

Yesterday, the Environment Secretary welcomed Dieter Helm’s excellent paper, “Flood defence: time for a radical rethink”, which highlights the critical role played by land use in both causing and helping to alleviate flooding, especially the protection of natural capital in upstream areas. Pickering in North Yorkshire has attracted some attention this week, highlighting how efforts to slow the flow of water from the hills prevented the town from flooding this time. I know that that is not the only example. The Environment Secretary has said that she wants the results from Pickering to be used more widely, so how is she going to make that happen?

Dieter Helm also highlighted the thorny issue of how some agricultural policies and associated subsidies pay little or no attention to flood risk dimensions. The examples he gave included greater exposure to rapid run-off from the planting of maize; the burning of heather to improve grouse moors, as it reduces the land’s retention of water; and farming practices in the upper reaches of river catchments. Helm sets out how adaptation measures in these areas, such as the planting of trees, could have some of the greatest potential benefits for reducing flood risk.

Very interesting to hear what Richard Benyon MP (a former DEFRA floods Minister) had to say:-

One of the great knee-jerk reactions among many commentators—including, I am afraid, some Members of Parliament—is to say that the panacea for all flooding events is dredging.

If we want to improve the rivers, we must consider wider catchment issues such as land use management. We should bear in mind the extent to which farming has changed in recent years. If we look at a map of the Bristol channel two years ago, when all the excitement was going on around the Somerset Levels, we see a large proportion of Somerset being washed into the channel in a plume of silt. That was caused by farming practices higher up, not in the area where the flooding was taking place.

Undoubtedly there is a lot more in that debate that I haven’t picked up yet – here for example are Mark Avery’s views (the former Conservation Director of the RSPB) – he is particularly interested in the management of grouse moors and the fate of hen harriers.

Glastonberry 13

Finally, at least in Parliamentary terms the Environment, Food and Rural Affairs Committee met to start of review of the floods and the lessons that need to be learnt. Unfortunately the first session was dominated in media terms by why the Chairman of the Environment Agency was in Barbados and not in the north of England – see here for example. I haven’t yet seen the full transcript of this session yet but you can watch it all here on Parliamentary TV.

The Guardian reported:- Screen Shot 2016-01-07 at 11.38.23Hopefully more will follow from future sessions of the Committee.

Liz Truss yesterday also spoken at the Oxford Farming Conference – you can watch that speech here. A lot about the importance of farming for food security and little about farmers’ responsibilities to the environment! In advance of her speech it was trailed that she wanted to give farmers the powers to dredge ditches on their land – see here. This statement has been met with disbelief from some quarters – see Miles King’s excellent blog here, here and see the second part of this BBC report here.

I spent some time a couple of days ago talking on the phone to Jeremy Pursglove (author of Taming the Floods) who I haven’t seen for about 11 years! We were comparing notes about what needed to be done to deal with flooding in a world where ‘exceptional’ has become the ‘normal’. This was my starter for 10.

  • Clearly some places need more flood defences
  • Upstream measures such as at Holnicote  and at Pickering
  • Much more attention to land use, for example in places where there are steep slopes running into streams and roads don’t plant maize here as the compacted soils will shed the water immediately
  • A grounding out of the de-silting / dredging argument
  • Decanalising rivers / reinstating meanders.
  • Allowing flood plains to flood – removing bunds which protect farmland
  • More trees in the uplands in the right place (i.e. not in historic landscapes or Special Areas of Conservation etc) but not more conifer plantations …..
  • A review of upland grazing so that ecosystem services can be delivered – this doesn’t mean no grazing animals but it might well mean fewer of them
  • And of course no development in flood plains

Interesting times ahead – despite all the noise in the system, the conflicting DEFRA announcements and some very entrenched and partisan views there is a real opportunity here and now.



Calm after the storm

Yesterday in my blog I had some pictures of the little brook in Exton in full spate – see here. It has all calmed down again now.

Exton brook
All the water is back in the channel

Sun catching the pollarded willow

Blue sky through the alder branches

Pied wagtail
A pied wagtail checking through the flood remains for a meal

I had quite a bit of feedback to yesterday’s blog especially around the issue of cross compliance – that is the basic practices that farmers need to carry out in order to be eligible to claim their subsidies. Apparently on the 31/12/15 DEFRA updated the guidelines which need to be followed in 2016! I will be looking into that today and will update my blog in due course.

The brook in Exton is running brown again with maize field mud

I know I have been writing a lot recently about flooding, maize and brown flood water but when you keep waking up to the little stream beside your garden thundering with brown flood water you take quite an interest in it.

Exton brook2
The scene Sunday morning after last night’s rain.

Exton brook1An amazing colour – super loaded with Devon’s soil

Exton brook3Flooding in Station Road

I was even visited by a couple who live in Station Road in Exton who had read my previous blog on the flooding in the village. They were asking me about the maize connection. As a result I have been looking more deeply into what has been published on the topic.

For me, the key piece of research was undertaken by RC Palmer and RP Smith which was published in the journal Soil Use and Management in 2013  and was titled Soil structural degradation in SW England and its impact on surface-water runoff generation. You can download and read the paper here.  The summary of the paper states:-

“Field investigations between 2002 and 2011 identified soil structural degradation to be widespread in SW England with 38% of the 3243 surveyed sites having sufficiently degraded soil structure to produce observable features of enhanced surface-water runoff within the landscape. Soil under arable crops often had high or severe levels of structural degradation. Late-harvested crops such as maize had the most damaged soil where 75% of sites were found to have degraded structure generating enhanced surface-water runoff.”

“Remedial actions to improve soil structure are either not being undertaken or are being unsuccessfully used.”

“Brown Sands, Brown Earths and loamy Stagnogley Soils were the most frequently damaged soils. The intensive use of well-drained, high quality sandy and coarse loamy soils has led to soil structural damage resulting in enhanced surface-water runoff from fields that should naturally absorb winter rain. Surface water pollution, localized flooding and reduced winter recharge rates to aquifers result from this damage.” 

When this paper was first published George Monbiot wrote a piece in the Guardian – see here, where he suggested that government policy was partly responsible for the flooding of people’s homes by supporting and encouraging unsustainable farming practices including the growing of maize in unsuitable places.

Dr. Andrew Clark, Head of Policy Services at the NFU, responded furiously – see here, stating that farmers took their responsibilities seriously and if they didn’t you would not be eligible for their farm subsidies. He also concluded by stating

“The Journal of Soil Use and Management actually considers the impact that cropping and soil management can have on surface water flows at a field scale. It does not consider the impact of cropping and soil management on flooding. The lessons we should learn from this winter’s floods is all areas, both urban and rural, should be acting across entire catchments to find solutions.”

He seems to be suggesting here that the role of maize in flooding was therefore unproven. I would suggest that Dr. Clark hadn’t read the paper. The paper includes the following

“Archer et al.  demonstrate a link between land use and floods at catchment scale. They show from studies in the Axe catchment in Devon that rates of change in discharge volume respond to land use change at both the small and large catchment levels. The clearest evidence for this relationship was for moderate floods resulting from rainfall events of 10–30 mm/day.”

Robert Palmer one of the authors of the paper was pretty cross with the NFU comments and had the following published in the Guardian –  Maize farmers must take some of the flood blame – see here. I quote the majority of his reply below.

“The National Farmers’ Union doesn’t appear to grasp the seriousness of soil structural damage (compaction or squeezing the life out of soil) and its implications for water movement in the environment.”

“In my extensive field study of 3,243 sites, 75% of land under maize showed serious structural degradation (smeared, rutted and severely compacted) and was producing enhanced surface runoff across the fields. This is inevitable when crops are harvested late in the year (October and November) by heavy machinery.”

“Some 30% (93 sites) of this degraded maize land carried well-drained, naturally permeable soils over aquifer rocks. Historically, rainfall on these soils readily percolates vertically down through the soil and recharges groundwater resources. After maize cultivation, the damage to soil structure is so severe that rainfall cannot penetrate the damaged upper soil layers, and lateral surface runoff results.”

“A typical winter atmospheric depression (now referred to in the media as a storm) will produce 20-30mm of rain over a 12-hour period. Optimistically, assuming that up to one half of this rain percolates into these damaged maize soils, this leaves the volume of half an Olympic-sized swimming pool (in excess of 1m litres of muddy water) to be shed laterally across the surface of this “sealed” land for every 10-hectare block of maize stubble. So this winter, when the Meteorological Office reports 30 “storms”, every 10-hectare block of damaged land under maize stubble has produced the equivalent of 15 Olympic pools (more than 375m litres) as enhanced runoff. And 196,000 hectares of maize were grown in 2013, an increase of 24% on 2012. How can the NFU fail to understand the implications of this land use for catchment flooding?”

These are strong words from a scientist and what he is saying is pretty unambiguous.

So how does this relate to the catchment of the Exton Brook? Unfortunately I don’t know how many hectares of maize is grown in the catchment but it is plain for all to see that a considerable amount is. I have had a look at the soil map for the area to see if that offers any insights. Soil maps for all of England are freely available here.

Soils around Exton
This is a screenshot of the soil types around Exton – the predominant soil type from the catchment is ‘Slightly acid loamy and clayey soils with impeded drainage‘ and is the darker brown colour on the map.

The description for this soil type can be viewed here. Interestingly and tellingly it states the following:-

Water protection issuesFarmed land is drained and therefore vulnerable to pollution run-off and rapid through-flow to streams; surface capping can trigger erosion of fine sediment

General cropping guidanceReasonably flexible but more suited to autumn sown crops and grassland; soil conditions may limit safe groundwork and grazing, particularly in spring

The growing of maize and its associated autumn harvesting on these soils is exploiting the soil’s core vulnerabilities and is leading to the rapid muddy flooding.

Unfortunately the recent construction of two anaerobic digester plants (AD plants) nearby to the east of Exeter has encouraged local farmers including those in the Exton brook catchment  to supply maize to these power stations. The maize grown in the catchment is one of the key materials used to generate biogas (methane and carbon dioxide) which then powers the combined heat and power plant – see here for more details of anaerobic digesters.

The government (via DEFRA and DECC) have produced an Anaerobic Digestion Strategy and Action Plan – A commitment to increasing energy from waste through Anaerobic Digestion – see here. However this strategy has led to the increased growing of maize simply to fuel the power stations. Maize however grown on farmland where food could be grown can hardly be viewed as energy from ‘waste’.

DEFRA have also produced a soil strategy: Safeguarding our Soils – A strategy for England – see here. It states this as its vision “By 2030, all England’s soils will be managed sustainably and degradation threats tackled successfully. This will improve the quality of England’s soils and safeguard their ability to provide essential services for future generations.”

So we have two strategies from the same department working in opposition to each other.

So what can be done to improve the situation – that is, reduce flooding risk and improve soil conservation?

The Palmer and Smith paper does include some recommendations and some signs of hope.

“The Environment Agency has a programme of catchment studies to identify runoff problems and is working with partners, farmers and their advisers to deal with these problems. In East Devon, the Environment Agency funded a project where a subsoiler was purchased and made available to a local contractor who provided a subsidized service to farmers to deal with soil compaction identified by soil surveys. Sites were revisited after treatment and about 50% of these were found to be improved.”

“Farmers are becoming aware of the linkage between soil structural degradation and runoff generation, and it is in their own interests to improve soil condition where they can. The Maize Growers Association has led a successful campaign in partnership with the Environment Agency to improve the management of soil under maize. New early maturing maize varieties are being widely adopted, and frequently now maize stubble is being rough cultivated in autumn to remove topsoil compaction and surface damage.”

There is little evidence that the recommendations above are being followed in the Exton brook catchment – perhaps because many of the maize farmers are new to it as a result of the new AD plants.

Dr Clark from the NFU in his letter to the Guardian quoted above said

“It is simply not true to claim that farmers need do nothing to protect their soil and still be eligible for CAP payments. Every farmer receiving payment must complete an annual soil protection review. This requires farmers to identify problems – such as erosion and compaction – and set out actions on how to address them.” 

Unfortunately the protection that maize farmers need to apply to receive their CAP payments simply involves leaving the maize stubble in the fields over winter – the so called ‘minimum soil cover’ clause – see here for more details. And that clearly isn’t working and is urgent need of review.

Finally DEFRA should ensure that AD plants use waste and not specifically grown crops.