A flood of interest

Following hard on the heels of the previous record-breaking year, the close of 2016 marks the end of another warmest-year-on-record.  A warming climate is associated with greater frequency of intense storm events and flooding in the UK.  Climate change research back in the 1980s highlighted this association, and warned of rising sea levels and increasing frequency of flood events across much of the world. 

Thirty years ago, the UN's 1987 Brundtland Report brought the results of that research more fully into the public domain.  It highlighted the need for mitigation to reduce emissions of carbon dioxide and other greenhouse gases, and for adaptation to inevitable short-term change. Following two decades of limited activity, the UK's Stern Report back in 2006 provided evidence that the benefits to the UK of strong, early action would considerably outweigh the costs involved.  The earlier effective action is taken, the less costly it will be.

Sediment-laden flood water in a central section of the Eye Brook tributary of the river Welland in 2016

Flooding across the UK since then is consistent with climate change researchers' projections, and the UK Committee on Climate Change identifies flooding as currently the greatest risk associated with climate change. Insurance companies are taking the issue seriously as some properties become uninsurable and the risk associated with others becomes uncertain.  'Building resilience' is an increasing refrain from insurers, while the Bank of England expresses concern about financial instability associated with climate change.

Within our Water Friendly Farming project, we are investigating options for adapting to current flood risk trends by introducing permeable dams and supporting farmers in their efforts to improve soil management to attenuate flood peaks.  As well as potentially reducing flood risk downstream, better soil management can also reduce the effects on crop performance of water-logging, compaction and grass weed competition associated with a combination of heavy machinery and intense rainfall. 

Our continuing monitoring of flow at the base of each of the three study catchments will enable us to document actual change in due course.  We will be modeling the implications of our management on downstream water quality, sedimentation and flood risk under a range of rainfall scenarios.  Initial modeling results suggest that the management we are adopting may be better able to reduce the impacts of regular storm events than some of the more extreme ones that we are starting to experience more frequently than in the past.

The danger is that, as we focus on our response to immediate problems, we continue to neglect the increasingly urgent need for mitigation of longer term climate change.  In 2016, the UK government announced new targets for carbon emissions reduction by 2030 and became the 111th country to ratify the Paris Climate Agreement, signalling new national policy for climate change mitigation. This is one to watch as we enter 2017.

Within the Allerton Project, we contribute towards mitigation by adopting renewable energy and effective insulation, home-working and teleconferences, minimising flying and supporting local food producers.  But we need to do much more, as a society and as individuals, to mitigate climate change rather than just adapting to the consequences of it.  Recent American research suggests that the next thirty years may not be as kind to us as the previous thirty have been.  Our New Year's resolutions seem obvious enough.

Robin reliance

It's the time of year when we bring bits of tree into the house and send each other pictures of robins. Robins have featured on Christmas cards since Victorian times and have become as integrated into our mid-winter festivities as holly and mistletoe.  Even the technological advances of recent decades have not totally eclipsed our long evolutionary psychological integration with nature.

Robins are one of our most widespread and abundant species, occuring in woodland, on farms, and in urban gardens.  As a confiding and adaptable bird, the robin is a species which is much loved by a large proportion of people.  This is a species which has a strong cultural value.

Robin territory numbers at Loddington

Robins have fared well at Loddington.  Breeding numbers doubled between 1992 and 2001 during which time we carried out a combination of habitat improvement, legal predator control and winter feeding.  Numbers were 24% lower in 2006 in the absence of predator control.  In this, robins follow the trend set by species such as blackbird and spotted flycatcher whose nesting success and breeding numbers are influenced by the control of nest predators.  

Robin numbers were 56% lower in 2010 in the absence of winter feeding as well as predator control.  Robins are regular visitors to garden bird tables, and have also frequently been recorded using gamebird feed hoppers on the farm at Loddington.  Our Trailcam records even document robins feeding from hoppers at night.  Those big eyes which are no doubt part of the robin's popular appeal, are put to good use.  With predator control and winter feeding restored at Loddington in recent years, robin numbers are now at their highest level since 1992.

This sort of conservation management system has a cost, and this is met by a combination of private funding and government payments through initiatives such as the Countryside Stewardship scheme.  At times of political and economic uncertainty, searching questions are inevitably asked about expenditure at all levels, from government to individual farms and households.  The moral imperative for wildlife conservation aside, the case for public and private investment in wildlife is strong.

Each Christmas we demonstrate the cultural value we attach to robins, but the importance of this species, and countless others, extends much further.  The evidence for important benefits of wildife to human psychological wellbeing continues to mount.  Wildlife can reduce stress and anxiety, and increase positive mood, self-esteem and resilience, helping to reduce mental health problems which are an enormous and persistent social and economic national burden.  The robin is a seasonal reminder that, at times of political and economic uncertainty, arguably above all others, our wildlife is an asset which we need to recognise and support for our mutual benefit.

Water Friendly Farming project results

We launched our latest report on the Water Friendly Farming project at Westminster earlier in the week.  You can access a copy here.

The report covers the results of intensive data collection across five years, and three headwater catchments totalling around 3,000 hectares.  We weren’t surprised by the large turnout to the launch.  This is a project with exceptional experimental rigour, practical grounding and multiple objectives that are highly relevant to current policy for water management in agricultural catchments. The most notable results are worth summarising here.

Phosphorus concentrations at the base of the two ‘treatment’ catchments and one control catchment have increased during the five-year period.  Although high phosphorus concentrations are often associated with high sediment concentrations during peak winter stream flow, for most of the time, during base flow, high phosphorus concentrations are the result of discharges from sewage treatment works.  The increase may be influenced by the relatively low concentrations associated with high summer flows during 2012, but the fact remains that domestic sources of phosphorus are a major issue in rural catchments.  Both agricultural and domestic sources are difficult and slow to address but our research is improving our understanding of the issues.

Landscape scale aquatic biodiversity, as represented by aquatic and wetland plants, has increased in the two ‘treatment’ catchments in response to the creation of new wetland habitats, while remaining constant in the control catchment where there has been no such management.  This is the first unequivocal demonstration of this process and is extremely encouraging in terms of the potential for landscape scale conservation of aquatic wildlife on farmland more widely.

Modelling of our data suggests that a switch from plough-based crop establishment to a no-till approach could result in an 11% decline in peak flow and associated downstream flooding.  The same change in crop establishment strategy could also result in a 38% reduction in sediment load exported from the catchments under most rainfall conditions.  This would also help to reduce flood risk because of reduced sedimentation of drainage channels in the lower catchment.  We will be exploring to what extent such changes are feasible within the constraints currently expedrienced by farm businesses.

Our research continues. Take a look at the report for more detail, and I'll continue to post updates on this blog periodically.

Hedge management for nesting birds

The British lowland countryside is characterised by a network of hedges, a much valued component of our cultural landscape and a nesting habitat for countless birds.  Together with RSPB partners, we recently published a paper on the effects of hedgerow structure on the nesting success of these birds.  Our previous research at Loddington revealed that controlling crows and magpies had a beneficial effect on nesting success and subsequent breeding numbers of some species, and also that nesting success was influenced by the structure of the habitat in which nests were located.

As management of many hedges has been neglected in recent years, resulting in a more open structure, this could leave nesting birds more susceptible to predation than in the past.  Our monitoring of 399 nests over two years revealed that birds were choosing the denser parts of hedges in which to nest.  Nest survival was higher in hedges that had been cut four years before than in those that had been cut more recently (in the previous year), and nests fared better in mechanically trimmed, stock-proof hedges than in recently laid or neglected leggy ones.

This is encouraging.  While we have shown that the control of crows and magpies can have an important role to play in songbird conservation where landscape characteristics support high numbers of these species, our recent research shows that hedgerow management can also help to improve songbird breeding success on farmland.

Farming and flooding - investigating common ground

Payments to farmers are currently under review as a result of our forthcoming departure from the EU.  It will ultimately be up to the UK government to decide what farmers get paid, or more importantly perhaps, what they get paid for.  Leaving aside the production of abundant, affordable and nutritious food, what do UK tax payers expect from farmers in return for their financial support?

Through the life of our EU membership, wildlife conservation has been a primary focus for agri-environment schemes, and this continues to be a major concern for a substantial proportion of the population.  Landscape is another.  An abundant supply of clean drinking water is a fundamental requirement of the population as a whole and becomes increasingly challenging as that population increases, and changes in rainfall patterns influence reservoir storage.  Most recently though, it has been the frequency of major flood events that has risen up the popular and political agenda.

Farmers are also concerned about the increased frequency of intense storms in recent years.  Apart from the flooding of low lying farmland, intense storm events cause water-logging and compaction of soils which, in turn, result in deterioration in soils, increases in weed burdens, reduced crop yields, and increases in input costs.  All of this reduces both farm profitability and the production of our food.  Getting water off the land through improved drainage is an increasing priority for many farmers.

So what can farmers do to reduce, rather than accentuate flood risk downstream?  Over the next five years, we will be addressing this question as part of our research in the Water Friendly Farming project, a landscape scale experiment with the Freshwater Habitats Trust which started in 2012 and involves three headwater catchments. 

Diagramatic representation of headwater ditch or small stream showing the two opportunities for controlling flow during storm events - optimising soil management to improve its buffering capacity, and creating permeable timber dams.

While effective drainage on our clay soils is essential, there is scope to improve the water holding capacity of the soil above the level of the field drains.  Improved soil management that reduces compaction and increases organic matter and biological activity improves conditions for crops, but also increases the capacity of the soil to hold water when it rains. Even greater benefits can arise from reduced soil erosion because of the associated reduction in sedimentation of drainage channels downstream.  This is all very much easier to say than to achieve in practice, but we are providing farmers with whatever support we can to help them achieve this over the coming years.  In doing so, we can draw on our own practical and research experience at Loddington, and on specialist advice from others.

We have already been surveying some fields for soil compaction, organic matter and earthworm abundance, all of which influence both flood risk and crop performance, and sharing this information with farmers.

Recently constructed permeable dam in the Water Friendly Farming project study area

There is also scope for holding back water in ditches and small streams by using permeable dams.  Such dams can often be relatively simple to install and permit water to flow normally uderneath them for most of the time, but hold it back when the water level rises during heavy rain.  Retaining water in headwaters, even if only for a couple of hours, can reduce flood risk downstream.  We have just started installing such dams in one of the two treatment catchments in our Water Friendly Farming study area, using locally sourced timber and a local contractor. 

We are using a combination of hydrological modeling by Colin Brown at York University, on-site observation, and guidance from catchment farmers to inform the siting of the dams.  The objectives are always to maintain base flow, optimise water storage during storms, and avoid impacts on productive land.

Over the coming years, we will continue to provide whatever support we can to help farmers in the study area to improve soil management, and we will install permeable dams where it is feasible and effective to do so.  By continuing to monitor flow at the base of the three study catchments, and comparing these data with data already collected as part of our ongoing research, we will be able to evaluate the effectiveness of this approach in terms of reduced downstream flood risk.  Such data, and our experiences along the way, will help to inform the development of policy that enables farmers to be rewarded for carrying out work on their land which has benefits for people living far beyond the farm boundary.

Allerton Agroforestry

Identifying and understanding multiple benefits from single management practices has been at the heart of our research activity throughout the life of the Allerton Project.  There are few better examples of such multiple benefits than agro-forestry on marginal land.  A number of research projects across the country have explored its potential, but there has been no widespread adoption, in part because government land use policy has focused on single objectives associated with arable, pasture and forestry, and because of apparent limited application on productive land. Agroforestry systems are more widely accepted and adopted in many other parts of the world and I have been fortunate to conduct research into such systems in Portugal and West Africa, as well as following UK agroforestry research with interest.

Portuguese Montado is the classic agroforestry system with tree densities usually of 30-60/ha and multiple uses including cork and charcoal production, and shooting and wildlife conservation, as well as livestock and arable production.

We now have an opportunity to investigate the merits of agroforestry at Loddington.  A moderately productive pasture field that has been used for rearing lambs for many years has been planted with trees at a range of densities.  While maintaining lamb production from most of the pasture through our collaboration with Launde Farm Foods, the trees bring potential additional benefits. The tree species selected, and the inclusion of shrubs in some places, are specifically intended to improve the area for pheasant shooting. The trees and shrubs also provide a new wildlife habitat.  Through the influence of trees on the soil, we might expect increased carbon sequestration, enhanced soil biology and potential for flood peak attenuation through improved infiltration of water during storms.

The trees have been planted without support from an agri-environment scheme but with help from the Woodland Trust who are also supporting our research.  Two plots are planted with trees at a density of 100/ha to represent a relatively high agroforestry density, and these will be compared with other plots at higher tree densities.  Some are planted at 400/ha to represent the lowest permissible density for open woodland planting with government funding, and others are planted at 1,600/ha, the maximum density that can normally be funded for woodland creation.  Trees will be thinned in due course as part of the normal management of such a plantation, but differences in tree density will be maintained.  We anticipate very different results across this range of tree densities in terms of the trade-offs and synergies between our various economic and environmental objectives.

The next few years provide us with an opportunity to learn much about the management of the plots to meet our multiple objectives, and we will also be gathering data to help inform this process.  Our initial priority is to gather baseline data on grass yield and lamb production, tree canopy area, bird numbers, and soil biology, organic matter, compaction and infiltration. These data will ultimately enable us to make environmental and economic assessments of tree planting on pasture under a range of scenarios, and recommendations for future policy and practice elsewhere.

As the trees develop, we will explore the interactions between a range of objectives such as livestock production, carbon sequestration and flood risk management in relation to different tree planting densities.

Uncovering cover crops

Cover crops are very much a hot topic at the moment.  They seem to have so much to offer – improved soil structure and organic matter, retained nutrients, erosion limitation, and even blackgrass control.  But not everyone is convinced of their merits.  It’s all very well farmers with light land in the south extolling their virtues, but what of the rest of us?  And in these challenging economic times, do they pay?

We don’t have the answer to all these questions, but we are learning a lot about the potential of cover crops on cold wet Midlands clays through a rigorously designed experiment that has been running for the past year.  The research is part of our contribution to Defra’s Sustainable Intensification research Platform (SIP).  We are still analysing the data, but I can share some interim findings.

We looked at three different mixtures, oats and Phacelia; oats, Phacelia and radishes (oil and tillage); and oats, Phacelia, radishes and legumes (vetch and clovers).  We also had a bare stubble control plot in each of the three fields in which the experiment was replicated.  Our Soil Scientist, Dr Felicity Crotty has been gathering data on soil physical, chemical and biological properties, while our Farm Manager, Phil Jarvis is gathering yield and economic data.

Soil Scientist, Dr Felicity Crotty

Felicity quantified the effect of drilling the cover crops on soil structure in comparison to the bare stubble control which had not been driven over by machinery, and by the end of the winter, the soil structure had visibly improved and compaction was reduced in all the cover crop treatments while the bare stubble control remained unchanged.  The oats, Phacelia and radish mixtures had slightly greater plant cover, but importantly, significantly lower biomass of weeds such as blackgrass.  There were some significant differences between cover crop mixtures in soil biology, specifically surface dwelling earthworms and millipedes, which may have implications for organic matter breakdown and incorporation into the soil.  The radish based mixtures were also associated with the highest yield in the following spring oats crop, and lowest weed biomass, compared to the stubble control plots.  Further analysis, especially of the economic data, will enable us to evaluate these mixtures more fully.

Our interim findings for the first year suggest that cover crops can reduce weed populations and enhance yield through improvements in soil function, but we now need to discover whether such benefits justify the cost incurred by establishing the cover crops in the first place.  Meanwhile, cover crops have been established in a new experiment this autumn, this time looking in more detail at the specific components of the mixtures so that we can understand better the role of each species. 

The spring oats following last year’s cover crops have now been replaced by wheat.  Next year we will assess the yields of that crop in relation to the different cover crop mixtures.  Our aim is to understand the implications of cover crops, not just in terms of immediate costs and benefits, but also as part of a rotation.

Brexit - the long view

Now that the full ramifications of Brexit for farming, the environment, and all they provide for the UK population are becoming more fully appreciated, perhaps it is time for reflection.  A few years ago we did this by bringing together the latest agri-environmental science with the earliest available local community knowledge.  It was a fulfilling experience in improving our collective understanding of our past, present and, most importantly, our future management of the land.  The book that resulted from this project is now freely available from the British Library by clicking Exploring a Productive Landscape .

We recognised then that we have a few challenges ahead of us, not least the multiple increasing impacts of climate change, a growing national and global population, declining availability of natural resources such as land, fuel and nutrients, and economic pressure from global markets.  Brexit will influence the strategies adopted to address these issues in future.

There have been bigger changes before of course.  Dispersed Roman and Anglo-Saxon farmsteads were replaced by the feudal medieval open field system which, in turn, gave way to enclosure.  These were largely closed systems in which resources were recycled locally.  Without the protection of the Corn Laws, late nineteenth century steam power increased exposure of national food production to global markets and resulted in a long period of depression for the rural population. National food security was prioritised in the Second World War, and the 'Green Revolution' contributed to increased food production, world population growth, and our dependence on fossil fuels. How significant Brexit is in the context of these historical events remains to be seen, but there is no doubt that the consequences for the way the British countryside works for us all could be considerable.

Our membership of the EU has coincided with a period of increasing realisation that the recent historical trajectory is not sustainable.  EU-funded research collaborations across Europe have helped improve our understanding of agri-envionmental issues, and funding has been made available to reward farmers for delivering services that bring no immediate economic benefit to the farmers themselves, but result in multiple benefits to the wider population as a whole.  My involvement in a scientific review of agri-environmental issues for the EU back in 1999, first highlighted for me the wide range of scales, impacts and people associated with the management of soil alone.  Now we are embarking on our latest EU-funded research project, SoilCare, which specifically addresses the public and private benefits of improved soil management.

A combination of history and science reminds us that the delivery of this mix of public and private benefits must be a fundamental requirement for future agricultural policy.  As our research at the Allerton Project highlights repeatedly, a multifunctional approach to land management, delivering benefits at a range of scales, is what we need to aim for to achieve both an economically vibrant farming industry and an environment which underpins the health and wellbeing of our society as a whole. We increase the importation of food from outside Europe at the expense of social and enviromental damage elsewhere in the world.  There are increasing concerns that the implications of this for us are not confined to a troubled conscience, but contribute to increased risk of social and political unrest, as well as to multiple local and national impacts of global climate change. The world is a smaller place than it has ever been before.

The dialogue in Exploring a Productive Landscape seems particularly poignant now, given the constraints on farm profitability and public funding.  Economic uncertainy outside the EU means that we need to use the limited resources available to us more efficiently and more wisely than ever before.  The task now is firstly to develop, secondly to promote, and thirdly to support the methods by which farmers can deliver healthy soils, woods, wildlife and water, while also providing the food and energy that we all demand.  That will have a cost, but it is one that must be paid, not just for us, but for those who take up the baton for the next stage in our history.

Soils research underlying land management

Both the farming and scientific communities understand that soil physical properties influence our ability to produce food and make money from the land.  There is also an increasing acceptance that soil biology plays a role.  But how are soil physical and biological properties related? This is the question posed by Leicester University PhD student Falah Hamad.  He is currently in his second year of data collection.  At Loddington and another site in Cambridgeshire, he is collecting data across a range of land uses and soil conditions, from compacted arable land, through better structured arable soils and pasture, to established woodland.

Falah Hamad measures CO2 emissions from pasture

As well as soil physical properties and organic matter, he is carrying out repeated surveys of earthworms and measuring CO2 efflux as an indicator of soil microbial activity at each of the sites.  His results are already revealing how earthworm numbers respond to reduced soil disturbance, and how compaction and soil organic carbon differ across land uses.  These data also provide a valuable baseline for our continuing research at Loddington, and provide new data for pasture and woodland to help us build on our existing knowledge of arable land use.  They will help us understand some of the biological process underlying (literally) our management of the land.

This is useful to us, and helps us provide guidance to farmers and advisors through our ongoing knowledge exchange programme, but is it what farmers want to hear?  The knowledge and interests of scientists and farmers are not always perfectly aligned!  This is the subject of another PhD project being carried out by Stephen Jones from Nottingham University.  He is taking an interdisciplinary approach, combining social and natural sciences to compare the attributes attached to soils by scientists and farmers.

Are farmers and scientists looking for the same thing in soil?

In his research, Stephen will be interviewing arable farmers from a range of backgrounds to find out what they want soils to deliver for them.  He will also be gathering data on the soils themselves to apply scientific physical, chemical and biological attributes to those soils.  Such properties are relevant to the whole range of 'services' that soils deliver for society and to the policy objectives of government.  But how well matched are these societal and scientific objectives with those of the people actually managing the land?  Combining social and natural sciences within one study will help us find out and guide our future knowledge exchange activities.

Celebrating songbirds

It seems remarkable that I have now been monitoring songbird numbers at Loddington for a quarter of a century, carrying out eight early morning transect counts each summer.  Over that time, our research has expanded to cover a wide range of agri-environmental issues, influencing both policy and practice on individual farms, but our monitoring of bird numbers has continued unchanged throughout.  Long-term datasets such as this provide an insight into issues which cannot be explored through short-term research projects.

Linnet - now abundant at Loddington again

Long before the term ‘ecosystem services’ came into use, we carried out research into several wildlife species, recognising the important role they play in helping to meet our needs.  We have looked at spiders and predatory beetles in field margins and beetle banks because of the role they play in controlling aphids and other crop pests.  We have researched bumblebees, solitary bees and other pollinating insects because of their role in fruit-set of wild and cultivated plants.  We have investigated aquatic invertebrates which provide an indicator of the quality of our drinking water supply, and we are currently investigating earthworms and other soil invertebrates because of the important role they play in soil function.

Where does this leave birds?  Let’s accept that birds have an important cultural value.  Birds inspire us.  They provide the focus of attention for millions of bird watchers across the world, and bring satisfaction to countless others who observe them more casually.  Farmers are no exception.  As our recent PhD student, Susanne Jarratt was able to demonstrate, farmers learn about birds through their participation in agri-environment schemes and develop an appreciation of them.  Nearly a thousand farmers across the UK took part in this year’s Big Farmland Bird Count.  And let’s not forget that it was the study of grey partridges in Sussex, started by Dick Potts in the 1960s, that inspired the research that underpins our current understanding of the farmland ecosystem.  More recent research demonstrated that songbirds such as skylarks and corn buntings benefit from the management of farmland for partridges.

So what about the songbirds at Loddington?  What have my two hundred early morning bird counts revealed?  They show that songbird numbers have changed considerably in response to game management on the farm.  Following a baseline year in 1992, when we made no changes to the management, songbird numbers had doubled by 1999 following seven years of management for wild game.  From 2001, we kept the habitat management going, but stopped the predator control, and then from 2006, we also stopped the provision of winter food.  Songbird numbers dropped until, in 2009, they were little higher than the 1992 baseline. 

Songbird numbers are once again almost twice as high as in the baseline year of 1992

Introducing a reared pheasant shoot with limited predator control in 2011 did not result in the increase we had seen in the early years of the project.  However, research carried out by John Szczur and Patrick White identified the importance of predator control for some species and we have taken the decision to increase predator control specifically for these birds in the past couple of years.  Songbird numbers are now 90% higher than they were in 1992, while numbers in the wider countryside remain relatively constant.

While not all birds have increased, those which have include iconic species such as song thrush, whose song is appreciated by numerous visitors to Loddington each spring, and the more subdued spotted flycatcher which makes the remarkable 8,000 mile round trip from West Africa to join us each year.  Tree sparrows are now on more or less permanent view from our visitor centre, and blackbirds, linnets and chaffinches are amongst the other species to be thriving.  That is surely something to celebrate.