Why managing winter rainfall on arable land matters
© GNP For Kent farm manager and AHDB Kent Monitor Farm host Tom Reynolds, managing water has become much more challenging in recent years.
The amount of winter rainfall is higher than it used to be, he reveals.
This has caused the heavy land areas of the farm to have issues with standing water after deluges and occasionally threatening the local village of Postling when the road floods.
See also: Why one Essex arable farm faces difficult decisions in 2025
Farm facts
Tom Reynolds, S Salbstein Ltd, Postling, Kent
- Annual rainfall now as much as 1,200mm
- 332ha across two farms with 158ha in arable rotation
After a heavy rain event, water comes off the farm’s chalk downland areas and flows across some of his arable land.
This puts the drainage system under pressure and threatening to waterlog crops. “This isn’t the dry South East anymore,” says Tom.
“Pre-2000, our annual rainfall was in the region of 750-800mm, now it’s as much as 1,200mm.”
Changes
As a result, he has been updating the farm’s drainage system and has also changed the way that he manages the soil.
He is using an integrated approach to improve infiltration rates and its water holding capacity.
“Holding more water on-site is possible and there are now ways to monetise that so it can work for the business,” he acknowledges. “But our main purpose is to produce food.”
The farm has been predominantly no-till for the past 15 years, farmyard manure is applied and a varied, diverse rotation, which includes herbage seed, is in place.
Soil organic matter levels are good, which Tom partly attributes to the farm previously having a dairy enterprise.
“We have been doing what we can to continue to improve our soils and how they function, but it’s a slow and steady process rather than an overnight change.”
Preventing floods
More recent interventions include planting a hedge and establishing a 12m grass margin in a field by the village road, to try to help prevent it flooding.
Slowing the flow and making the most of rooting to build soil aggregation will help to reduce run-off, he believes, providing a benefit to the local community and wider society.
Tom has also put one particularly wet field into a herbal ley and has done some baseline soil measurements, so that he can collect some data over a three-year period.
Half the field is in a simple herbal ley mix, with the other half being a more expensive diverse mix, so that he can compare their impact.
“Not only was the field very wet, it also had a bad blackgrass problem, so there are agronomic reasons as well as weather-proofing reasons for doing so.
“In due course, it will be grazed by our suckler herd.”
Other on-farm solutions that Tom is planning include taking the bottom 1ha part of a wet field out of production and creating a wetland.
The farm has an Higher Level Stewardship scheme, so he will use a water storage option to help fund this change.
“It will become a tussocky grass area, which will also have biodiversity benefits for the farm.”
Adding in other small wetland areas could also be done, he admits.
“Putting them next to existing ditches makes sense – modelling work done by Tom at The Environment Partnership has shown that five small wetlands on this farm would reduce run-off by 10% but only involve taking 0.2ha out of production.”
Drastic action
Much more drastic action would be land cover change, he notes, although that may limit the farm’s productive capacity and its impact would have to be assessed carefully.
“Again, modelling suggests that turning two of our fields into woodland would reduce run-off by 61%.
“But how it would be paid for and how long it would take to deliver this result are still to be determined.
“There may be other sites that are more suitable for this sort of approach.”
Tom remains open-minded and recognises that the farm landscape has the potential to provide water storage solutions.
“For us, it’s about putting in practices or features that help with water management and allow us to keep farming most of the land.”
Integrated management approach to wet winters
Tom Reynolds, right, and Tom Young of the Environment Partnership © Louise Impey
Helping arable soils to cope with the UK’s increasingly wet winters requires an integrated management approach aimed at solving the “too much, too little” water problem that farming is at risk from.
Land lying wet over the winter period has become a familiar sight in the past few years.
Standing water and waterlogged soils have created difficulties with missed operations windows, disappointing yields and poor returns.
Making space for water on farmland is one part of an integrated approach.
However, the starting point on most farms is to improve infiltration rates and the soil’s ability to hold water, by focusing on soil health.
Getting more water into the soil profile matters for several reasons;
- it reduces run-off, erosion and any associated pollution,
- it builds in drought resilience for the drier summer months, and
- it helps ease tight workload windows and improve productivity.
“It is possible to hold water on-site and integrate it into the landscape,” says Tom Young of The Environment Partnership.
“A well-structured and free-draining soil with a good organic matter content will help relieve the flooding pressures that many sites are facing.”
Where run-off volumes are affecting farming practices, he notes that understanding more about landscape water movement and flow pathways helps to show how the catchment is functioning and what specific on-farm solutions are required.
“When you know where the water is coming from and where it wants to go, you can look at features that will allow you to keep farming that land while coping with the extra water volume.”
If ditches are struggling after a heavy rain event, a small wetland area, a scrape or correctly-sited pond might help, he suggests.
“Where there is lots of drainage to one area, these sorts of features are relevant and will reduce run-off.”
Land cover change is another possibility, Tom adds.
“This varies from siting grassy strips and margins strategically to taking land out of arable production, perhaps putting it into woodland or making a wetland habitat with rough vegetation.”
Infiltration tests
Conducting an infiltration test is a good way to assess the soil’s current ability to hold water and see if improvements can be achieved.
Take a 5in-diameter steel tube and drive it into the ground, before pouring in 1in of water and then timing how long it takes to infiltrate.
Compare the results from an in-field test with one done in a margin or under a hedge, advises independent consultant Niels Corfield.
“It often takes much longer for the water to percolate in the field and some tests even have to be abandoned after a time.”
Infiltration rate matters because there is one chance to get water into the soil, he points out.
“If it can’t get there during a rain event, you are at risk of drought later in the year.”
Appropriate management can influence the soil’s ability to hold water, he advises.
“It involves eliminating compaction, making maximum use of living roots and building soil structure.”
SFI actions for water management
Actions that cover the management and buffering of land next to watercourses, as well as those that encourage soil management practices, are already available as part of the Sustainable Farming Incentive.
Payments vary from £6/ha for soil organic matter assessments to £73/ha for no-till farming, £129/ha for multispecies winter cover crops, and £382/ha for incorporating herbal leys.
Pond and ditch management actions have payment rates of £4-£38/100m for ditches and £257-£424/pond.
More ambitious, “high priority” actions for managing arable land or grassland for flood resilience and water quality attract payments of £938-£1,241/ha.
In addition, where appropriate, the 6-24m 3D waterbody buffer strip action attracts a payment of £1,182/ha.
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