All you need to know about biobeds

This was the title for the final workshop of this series of three which has taken place at the Allerton Project, organised by Jim Egan, with funding from the Welland Valley Partnership and support from The Campaign for the Farmed Environment. The workshop was led by Andrew Down, a Catchment Sensitive Farming Officer with Natural England and there was a visit to the Allerton Project's own biobed which Farm Manager Phil Jarvis and team are currently building – see some pictures on his blog.

The most important step is planning what you are going to do. Looking at the overall spaying/farm yard operation is a great starting point as many farmers could use this as an opportunity to make the farmyard more efficient as well as more environmentally friendly. 

Visiting farmers discuss the Allerton Project biobed

The first decision is whether you want a biobed or a bio-filter.  If you have a covered sprayer filling area you should be looking at a bio-filter, and if you are working on an outdoor operating system then it’s a biobed that you need.  We discussed everything from permits and exemptions through to construction and costs.

If most farmers took a long hard look at how they currently operate they’ll see there are a range of environmental risks and a number of inefficient steps in the whole spraying operation.  An investment in new infrastructure might be the best way forward and hopefully this workshop helped to give some ideas as to where to start.

Forty percent of pesticides in watercourses comes from farmyards with between 60 and 100% of that coming from foil seals and tractor washings! Andrew also reminded us all that for a single pesticide the limit in drinking water is 1 part per billion which equates to 1 drop in an Olympic sized swimming pool, or just one slug pellet in a 100 metre length of ditch.  If we want to keep the chemicals we have, better managed sprayer filling systems and a biobed or bio-filter are worth considering.

Improved soil management giving improved yields

Another successful workshop for Welland farmers today, supported by the Welland Valley Partnership and the Campaign for the Farmed Environment.  Here's a guest blog from the Allerton Project's Jim Egan who organised the event - 

The line-up of speakers was very varied and I thought I’d share some of the key points I picked up from each one. Allerton Project Director, Alastair Leake kicked the day off by looking at why soil organic matter is important. Soil organic matter:

·         Improves seedbed quality
·         Increases water infiltration
·         Increases Water Holding Capacity
·         Helps keep nutrients available
·         Produces simple nutrients from complex organic molecules
·         Fuels the Carbon Cycle

He also talked about how worms can be a farmer's best friend!

Next up was Ron Stobart who is the Head of Agronomy Knowledge Transfer and Training at NIAB TAG. Ron was given the task of talking about rotations and how this can influence soil organic matter.  It was great to hear about some long term research and gain some new knowledge. Ron reinforced the messages Alastair had delivered. Soil organic matter influences physical, chemical and biological properties including:

·         Improved drainage/workability of heavy soil
·         Improved available water capacity of light soil
·         Improved stability of soil crumbs
·         Assists root exploration
·         Improved nutrient holding capacity
·         Releases nitrogen to plants
·         Encourages earthworms, soil fauna - those worms again!

'Why Grow Cover Crops?' was the topic that Phil Sumption from the Organic Research Centre was given. Apart from re affirming my belief that there is a lot that conventional and organic farmers can learn from each other, here are my key points from Phil’s presentation. Consider growing cover crops to:

·         add nitrogen to the system by fixation
·         prevent leaching
·         modify the availability of nitrogen and other nutrients
·         build soil organic matter and encourage microbial activity
·         prevent soil erosion
·         help with pest, disease and weed control

Last of the formal speakers was Matt Taylor from ADAS who tackled 'Recycling of Organic Materials to Land'. Again lots to learn but my key take home messages were: 

• Know what you are applying - use laboratory analysis
• Apply accurately and evenly - if you can use precision application machinery
• Make best use of nutrients - NPKS costs money but can boost yield which gives a better financial return

After lunch our guests went out with Allerton Project Farm Manager, Phil Jarvis to look at what we are doing here at the Allerton Project.

The early bird ... loses its eggs

Early nests are more susceptible to predation

The nesting season is underway for bird species such as blackbird and song thrush, but their nests are poorly concealed as the leaves are not yet on the trees and hedges. Analysis of our 11-year dataset by Patrick White previously revealed that early season blackbird nests were more susceptible to predation by crows and magpies than nests later in the season, although there was no such effect when nest predators were controlled as part of a game management system (1).  That work also revealed higher fledging rates and population increases during the period of low nest predation.

In another paper just published on-line (2), Patrick White's further analysis of nest data collected over the same period by John Szczur reveals that, as well as blackbird and song thrush, nest survival of dunnock, chaffinch and yellowhammer also benefited from the removal of nest predators during the breeding season as part of systematic game management. For whitethroat, the sixth species studied, there was no such effect.  However, when less intensive control of crows and magpies only was carried out, only blackbird showed higher nest survival.

1. White, P.J., Stoate, C., Szczur, J. & Norris, K. (2008) Investigating the effects of predator removal and habitat management on nesting success and breeding population size of a farmland passerine: a case study. Ibis 150 (Suppl.1), 178-190.

2. White, P., Stoate, C., Szczur, J. & Norris, K. (2014) Predator reduction with habitat management can improve songbird nest success. Journal of Wildlife Management DOI: 10.1002/jwmg.687

Welland farmers benefit from research

A workshop held at Loddington on Friday enabled sixteen farmers from the Welland river basin to benefit from research carried out by the Allerton Project and others into the control of blackgrass.  Thanks to Jim Egan for organising the event and to Stephen Moss from Rothamsted and Mark Hemmant from Agrovista for sharing their very considerable research experience with us.

Blackgrass is arguably the most problematic weed affecting farmers' ability to produce food from arable land.  Few herbicides are available to control this competitive grass, and some of those that are available are persistent in water and cause considerable problems for drinking water supply.  Farmers attending the workshop were told of the importance of these herbicides in the fight against blackgrass, but also of a series of complementary measures that can be taken to control the weed.

The Welland Valley Partnership supported this workshop as part of its programme of activities to improve water quality in the River Welland, while also helping farmers to use the resources available to them as efficiently as possible.  A workshop on 19 March will address the subject of soil organic matter management, and another on 25 March will introduce visitors to the Allerton Project's new biobed.

Allerton Project Director, Dr Alastair Leake discusses the role of spring beans in blackgrass control with Welland farmers attending the recent workshop

Do constructed wetlands work?

Our research with Lancaster University on the potential of field corner constructed wetlands to reduce sediment and nutrient movement to water has just been published*. Three designs were tested across three soil types, including sandy and silty soils in Cumbria, and our clay soils at Loddington.  Although rainfall inevitably had a major influence on sediment accumulation, wit more rain in Cumbria than at Loddington during the study period, the influence of soil type was considerable.  Sandy soils accumulated 0.8 tonnes per hectare of catchment per year, silty soils 0.4 tonnes, and Loddington clay, 0.03 tonnes.  Phosphorus concentration was highest in sediment with low particle size but this had little influence on the effect of soil type on overall accumulation of phosphorus.

Sediment accumulation behind a WFF project ditch dam

So does this mean field edge wetlands have limited potential in catchments with clay soils such as those of the Water Friendly Farming project?  It does seem that wetlands in sandy and silty soils are likely to capture sediment more rapidly, but we know from previous work at Loddington that simple ditch dams can be very effective at both accumulating sediment and providing biodiversity benefits.  Similar structures created in the Water Friendly Farming project have also already proved to be effective at some sites.  The current study involved only three wetlands, and as we report in the paper, siting of such wetlands is critical to their performance.  In terms of practical application, flexibility in design is also critical so that the structure can be adapted to site specific constraints and opportunities to optimise sediment and nutrient capture.  Finally, wetlands that fail to capture fine particulate matter associated with clay soils, and those on sandy or silty soils that fill up quickly, both indicate that appropriate soil management in the field is the most fundamental approach to reducing soil and nutrient loss to water.

*Ockenden, M., Deasy, C., Quinton, J., Surrindge, B. & Stoate, C. 2014. Keeping agricultural soil out of rivers: Evidence of sediment and nutrient accumulation within field wetlands in the UK.  Journal of Environmental Management 135: 54-62.