Elveden Estate – LEAF monitor and SPot Farm

Frances Wright explores some of the benefits of being a LEAF farm and how the second year of AHDB SPot Farm trials fit with these principals.

Being a LEAF (Linking Environment and Farming) Demonstration Farm means looking at practices with a more holistic outlook than demanded by best practice, says Andrew Francis, farm manager at Elveden Estate. “LEAF helps you develop a new mind-set, such as your thought processes on strategic business management; you think of things which otherwise you would not take into consideration,” he says.

The farm has been a LEAF member for more than ten years, and a Demonstration Farm since 2013. He pays tribute to the support and access to ideas available only to LEAF members, which have helped to stimulate his work.

“The LEAF network provides you with an effective skeleton which is structured to help you make changes; there are always challenges when you do something a different way which can make you reluctant to make changes. When you become a LEAF member you are buying into support from board members who have a wealth of experience and can offer you helpful advice on how to avoid pitfalls.”

Members also provide inspirational examples of different production systems that Andrew, whose farm specialises in onions and potatoes, would not normally have access to. He has benefitted from insights into farm systems used with livestock and combinable crops by taking away their best practice regimes and using it as a skeleton to build on at the Elveden Estate.

“You have access to ways of approaching good practice which you can then adapt and use in your own business. Using this method gives you confidence in the network and structure which you can then flesh out with your own applications by adding your own personal touch.”

He sees benefits to the mentoring approach, which challenges farmers to check and counter check their practices to seek better ways of working. For example, the needs of vegetable cropping often results in headlands being left bare over winter. This can lead to them becoming weedy with compacted soils causing problems in the next crop in the rotation.

“We find these headlands can sit for a year not doing very much, but then they do not provide optimal conditions when we plant our cereals, resulting in many seedlings not getting away.”

This year he is trialling a green cover crop suitable for pollinators; not only will it benefit the environment and provide competition for the weeds but also take-up any water from irrigation overlaps. As it will have added benefits around the field as well, this is a multi-faceted outcome from solving a commercial problem. “This is a short-term solution to an annual problem, but if you do an increasing number of this sort of work, it becomes very effective,” he says.

His long-term objectives include exploring how to work with permanent field boundaries and margins to try and build an environment which would benefit pollinators. He is assessing mixes suitable for planting in the headland areas as part of the rotational provision and he hopes the bees will follow these pollinator mixes round the rotation.

“In our area on the Norfolk/Suffolk borders, with our Breckland grasses we are able to provide a good environment for invertebrates, but we need to do more for the pollinators.”

Incubating beneficial predators is also an idea on his radar for the longer term; he would be interested in discovering which plants provide the best reservoir for aphid predators so that when the pest appears the predators are ready to strike.

Catch crops which could attract aphids could also play an important role in the future. Planting a catch crop on a 12m margin next to a susceptible crop might attract up to 90 per cent of the pest. “The catch crop would not have to be a food crop so we could control the aphids with conventional plant protection products; at the same time, it would significantly reduce the amount we use on the food crop apply – helping us to keep under maximum residue limits (MRLs).”

Andrew sees a gap in this sort of knowledge in the farming sector, which potentially could be provided by a botanist and an entomologist. “Benefits from this sort of work need measuring, but how we could measure the direct and indirect effects needs to be worked out. Nevertheless, if we can show measurable benefits it will lead other people in the right direction.

“My policy is take a new idea, try it – you may learn something new – but do not make sweeping changes; if it works then multiply it up bit by bit. Then you can embed it as standard practice.”

Andrew sees the work with LEAF as a natural extension of the focused trials which are being undertaken in his second year as host of the AHDB Strategic Potato Farm East (SPoT). This year’s trials will build on last year’s work, some of which had brought forth surprising results. “Last year raised some interesting questions which we are seeking to address with these new trials,” he says.

AHDB SPot Farm East trials

This year’s demonstration plot on common scab will be backing up ten years of previous work on the use of water to control common scab. Work will continue looking at combinations of timings and amounts of water to determine the optimum cost-effective scab control strategy for the farm across a range of varieties.

Andre says, “the response to control is not always the same; some varieties are more resistant than others, and therefore need less water for a shorter period. As water becomes more scarce, particularly in this area of the country, we are looking to do more with less. We need to know whether we can continue with our current practices or need to refine them.”

Getting the most from irrigation and N applications

Small amounts of nitrogen (N) were not being taken up by the crop, last year’s trials revealed, but the probes used had been designed for use in greenhouses, so were not robust enough for use in the field. As a result, the experiment is being repeated to give Andrew more statistically valid information on nitrogen (N) movement in the soil.

“Last year we looked at N application timings, but the information needs complementing with how much to put on and when, and differences between placed and broadcast N, to bring in more detail.

“We have to find the sweet spot between optimum uptake and inefficient use. We also need to know where it ends up if it is not taken up by the crop. There are varieties which run out of steam, so we need to know the optimum time to apply N – and when it is too late.”

The on-farm water supply is from an aquifer, so Andrew needs to be aware if N is going through the soil and any potential there may be for creating problems. Everyone shares broad responsibility for ensuring clean, sustainable water, he says. He is working with Anglian Water, the Rivers Trust and Cranfield University to discover the best way to minimise potential impacts on the water in the aquifers. He has also called in further support from NIAB CUF and CUPGRA (Cambridge University Potato Growers Research Association).

He is also looking at reducing run-off from heavy rainfall events or irrigation overlaps, by disturbing tractor wheelings with the use of a Wonder Wheel. “There is a lot of traffic on fields used for potato growing creating compaction; not only do you have the destoner and the planter, but also the regular wheelings from irrigation and spraying crop protection products. These provide conduits for water runoff, possibly taking sediment and nutrients, too.”

Life after linuron

With linuron’s demise getting closer, Andrew is searching for guidance for the best options for controlling weeds in potato crops. There are alternative herbicides available, but some of these can cause scorch on certain potato varieties – and sandy soils can exacerbate this – while others are much more expensive.

Moreover, he has found residual herbicides can affect the crop following potatoes, particularly onions. This year he is looking for the SPot Farm to provide guidance on optimum rates and mixes for a cost-effective herbicide. “We need to find the sweet spot where the herbicide will do a good job but price per hectare is not astronomical.”

484 trial plots have been set-up to evaluate herbicide rates across a number of varieties.

“To make the best choice of herbicide you need to know your weed spectrum and your variety, and whether the variety is able to break the herbicide down – otherwise it will sit in the canopy.”