Hidden benefits of grass margins

We know from our previous research, and from other studies, that earthworms and other soil organisms are essential to soil functions that influence crop performance, water quality and flood control.  Our research has also shown that these organisms benefit from stable soil conditions associated with reduced tillage and no-tillage systems of crop establishment.  Soil life is enhanced by crop rotations in which the soil is not disturbed.

Desirable though this might sound, achieving these conditions is not so straight forward.  At some stage in the rotation, it might be necessary to plough for root crops, or because of wet conditions or for weed control for example.  The biological communities in the soil are rapidly destroyed and organic matter mineralised following cultivation.

Pasture provides a refuge for soil organisms such as earthworms but is not present or sufficiently well distributed on many farms.  On these farms, grass margins created under Environmental Stewardship schemes may provide an alternative refuge from which colonisation of arable soils can take place.

Worm numbers in grass margin and along transects through arable fields

MSc student, Stephen Jones recently completed his research into this issue in our School Farm catchment.  Worm numbers, biomass and species richness were all greater in grass margins than in the adjacent wheat or first year grass ley fields, with values for the first metre inside the field being consistently intermediate between those of the margin and main field.  There was a higher density of worms in fields next to Environmental Stewardship margins than in fields next to narrower cross-compliance margins.

These findings are important as they suggest that grass field margins, especially those created within Environmental Stewardship schemes, serve as a potential reservoir for recolonisation of arable fields when worm numbers become depleted by intensive cultivation.  The same may be true for other soil organisms.  Given the importance of earthworms and other soil organisms for soil function, including crop rooting capacity, nutrient cycling, water quality and flow control, the benefits of grass margins may be considerably greater than has formerly been assumed.

A great new opportunity

We are to be part of a major new Defra initiative called the Sustainable Intensification Platform (SIP).  Our combination of farm and landscape scale study areas at and around Loddington will become one of a network of five such areas across England and Wales.  The decision follows a lengthy and highly competitive selection process and is testament to our pioneering research at a range of scales over the past two decades.  The study areas are not just individual sites, but incorporate several activities at the landscape scale.  In our case, this involves building on existing projects ranging from our own farm at Loddington, through our 'School Farm' demonstration catchment, to our Water Friendly Farming experiment in the headwaters of the Eye Brook and neighbouring streams, and to the river basin scale through the Welland Valley Partnership. Collaboration is key to our research.  This involves numerous people, and I would like to thank those who have supported this bid directly, and by contributing to our work over the years, enabling us to become one of the five national SIP study areas.

Our current study area (green circle) around the upper Eye Brook and Stonton Brook tributaries of the River Welland, with the Water Friendly Farming project in the headwaters, and our own farm at Loddington outlined in purple.

On our own farm at Loddington, Alastair Leake's role has been pivotal in facilitating the increasing emphasis on soil management, developing a new eco-build visitor centre to enable us to expand our activities, and translating research findings into policy.  John Szczur has brought exceptional knowledge of animal and plant identification and ecology to the project at Loddington for more than twenty years, as well as being at the core of our data collection at the landscape scale.  As Farm Manager, Phil Jarvis plays a central role at Loddington, juggling the needs of the farm business with those of our research trials, while Jim Egan plays a key role in disseminating information to the farming community nationwide through initiatives such as the Campaign for the Farmed Environment and the FWAG Association.

Outside Loddington, collaboration is key.  In the School Farm demonstration catchment, thanks to our neighbours who own most of the area, and especially to Gareth Owen on whose farm we will be concentrating our efforts on livestock and grassland research and demonstration with Nottingham University.

At the larger catchment scale, thanks to the numerous local people who participated in the Eye Brook Community Project in recent years, raising both awareness of agri-environmental issues locally, and the profile of the Eye Brook catchment nationally.  Thanks to Jeremy Biggs and the rest of the Freshwater Habitats Trust team for all their work on the Water Friendly Farming project over the past three years, incorporating the Eye Brook headwaters and two neighbouring catchments.  We look forward to developing this work further.

These various initiatives are nested within the upper Welland river basin and I would like to thank our partners in the Welland Valley Partnership, a collaboration of statutory agencies, local authorities, businesses, and NGOs that provides a forum for local knowledge exchange, extension of our research experience, and practical action on the ground.

Our research and associated demonstration activities are usually carried out as partnerships with other research organisations from across the country, including numerous co-supervised PhD and MSc students.  The universities of Cranfield, Lancaster, Reading, York, Nottingham, Leicester and others have all contributed to our research over the years, as have ADAS, CEH, Fera, Rothamsted Research, RSPB, BTO, NIAB TAG, Anglian Water, Syngenta, Michelin and Agrii SoilQuest.  This collaborative approach has enabled us to carry out a wide range of interdisciplinary research combining natural and social sciences.  We look forward to further collaborations with these and other partners through the SIP, especially and most immediately with Nottingham University, Exeter University and NIAB TAG.

Finally, thanks to the many farmers in our local area who have supported our research in many ways.  We intend that the SIP will provide real opportunities for their farm businesses through the research that we will carry out with their inspiration and participation.  An oxymoron to some, the concept of 'Sustainable Intensification' is in essence about optimisation - finding an optimal balance between food security for a growing global population, resource use efficiency, conserving biodiversity, improving water quality, mitigating and adapting to climate change, and other economic, environmental and social objectives for the agricultural environment.

Apart from being an affirmation of the value of our research activities to date, the SIP will provide additional financial and academic support to enable us to develop our approach further, and will strengthen the translation of our research findings into policy and practice.

Land use and water quality

MSc student, Alejandra Barrios Rivera (York University) has just completed her time with us, exploring the relationship between land use and water quality in the three headwater catchments of the Water Friendly Farming project.  Thanks to Julie Ewald and Nicholas Aebischer at the GWCT headquarters in Fordingbridge for providing support with GIS and stats.  The data Alejandra used (provided by the Freshwater Habitats Trust) were from the February and March 2013 sampling period and comprised 94 samples from stream sites and 51 from ditches.  This 'should' have been a wet time of year, enabling us to examine the impact of runoff from land, but as it happened, rainfall was 68% lower than usual and so the sampling period is more representative of lower flow conditions.

The three catchments of the Water Friendly Farming project, showing major land uses

Total nitrogen and total phosphorus concentrations in the three catchments were broadly similar.  For both total nitrogen and total phosphorus, upslope woodland area reduced concentrations in water.  For total nitrogen, the upslope arable area was associated with higher concentrations, while for total phosphorus it was the upslope urban area that was associated with higher values. Nitrogen tended to be present at higher concentrations high in the catchments, while for phosphorus, highest concentrations were towards the base of the catchment. Neither slope nor soil permeability influenced nutrient concentrations in water, as might be expected for the relatively low rainfall conditions at the time of sampling.

These findings reflect other results from the project and from our other local monitoring, revealing a high impact of local residents on water quality through discharges from septic tanks and small rural sewage treatment works.  Nitrogen was associated with arable land but as elevated concentrations were recorded high in the catchments where settlements tended to be located, there may also have been a contribution from domestic sources.  We will need to examine data collected under wetter conditions to understand better the agricultural contribution under higher flow conditions when we know that sediment and phosphorus delivery to water from arable land is higher.