It’s going to be wetter in the winter and drier in the summer.

But there are also going to be more extremes, says Tim Wheeler of the Department of Agriculture at the University of Reading’s Walker Institute for Climate System Research, who believes this will be the biggest challenge for arable farmers.

“Coping with the increase in variability will be the most difficult,” Prof Wheeler warns. “More prolonged and frequent droughts and floods, together with an increase in storms and other extreme weather events, are much harder to plan for than a gradual increase in temperature.”

Last winter’s heavy rainfall means only six months in, 2014 is already the wettest year on record, he says. “The second wettest was 2012 and four of the five wettest years since monitoring began have all been since 2000.

“So the patterns we’re seeing are in line with what the meteorologists expected.”

Added to this, it’s also getting warmer, points out Prof Wheeler. “This year, Scotland is on course for its second warmest year since records began. Worldwide, the warmest year ever recorded was 2010, while thirteen out of the fourteen warmest years have all been in the 21 century.”

Warmer temperatures increase the evaporative demand of plants and need for water, he says. “So coping with dry periods will also become a reality for growers. What is deemed to be an unusual year now will become a much more frequent event in the future.”

That means events such as the heatwave experienced across much of Europe in 2003, considered to happen once every 250 years at the time, will happen one in every two years by 2050, he explains.

“The relevance of that to the arable farming industry is that it knocked wheat production in Europe by 10%.”

The good news is that warmer seasons and higher levels of atmospheric carbon dioxide should improve productivity in the UK and across northern Europe for the next 10-20 years, says Prof Wheeler.

“Providing there is sufficient water, the longer growing seasons will be an advantage. But other major grain producers, such as Australia and the USA, which are already more sensitive to the climate, will suffer.”

However, a change in the distribution of crop pests and diseases should also be expected, he warns. “As it gets warmer, we will see new problems developing. Many of them are weather dependent, especially if the overwintering stages aren’t killed off by cold temperatures; research shows Europe gets a new pest or disease every ten months.”

For farm businesses, making an investment to help cope with weather extremes is difficult to justify while they are still infrequent, he acknowledges.

“It takes 20-30 years for the climate to fully change, so there’s no need for hasty decisions. But once the gases are already in the atmosphere, there’s a commitment and the laws of physics mean there will be a change.”

He outlines some different approaches for growers, all of which can be used to help a business cope with climatic variability.

“The first is to wait until an investment in either irrigation or better drainage becomes financially viable in most years,” he says. “A good example of this is irrigating wheat.

“Alternatively, having other options, such as a diversification or different cropping, is a possibility. We’ve seen the raspberry sector move to new varieties that are better adapted to warmer conditions, for instance.”

His final point is that financial insurance products, such as those used in the USA, could be developed for the UK market. “These would allow for some risk management.”

Time to rethink farm plans in face of volatile weather

Prevent profits from drying up

Investing £2.2m in water supply during the past seven years has allowed the Euston Estate in Suffolk to maintain its output and continue to produce top-quality crops.

The need to irrigate every year, even in 2012, means that variability in water supply is a huge risk to the predominantly light land business, explains estate director Andrew Blenkiron, who has overseen the construction of one reservoir for winter water storage and is now in the process of building a second.

“Once that’s completed, we will have the ability to irrigate the majority of the farm, which stretches to 2,524ha,” he says. “It’s all about future-proofing the business.”

Irrigation is essential for the potato, onion and carrot crops that are produced by Euston Farms, where the focus is on added value, he adds. “To get the marketable quality that’s required, we have to keep them watered, usually until harvest.

“Most of these crops are grown on Breckland sands, which hold very little soil moisture, so drought and moisture stress are constant threats to profitability.”

Sugar beet, which is also grown at Euston Farms, is irrigated when sufficient water is available and conditions warrant it, he adds. “But that’s for very different reasons. The water helps to bulk it up and increase yields, rather than improve quality.”

It worked very well last year on 36ha of late-sown sugar beet, which had to be redrilled after wind blow, he recalls. “It was irrigated in September and we ended up with a respectable yield as a result.”

While the business has the potential to irrigate its cereal crops, the economic returns from doing so are much tighter, he reveals.

“We only have sufficient soil moisture for combinable crops in three out of every five years. But irrigation is dependent on the grain market – when wheat is £220/t it can be worth doing, but at £120/t it isn’t.”

This year, root crop irrigation started in April, once soil moisture deficits had fallen, reports Mr Blenkiron. “It’s been warm and windy, which are ideal conditions for transpiration, so we’ve been irrigating ever since.”

Otherwise, the risk of even drier summers has prompted him to reduce the farm’s wheat area. “We’ve replaced some of the wheat with forage maize, which will be used in an AD plant. Maize doesn’t need as much moisture as wheat and is drilled in April, rather than September.”

Even so, he admits to retaining 20-30mm of water until May, to help establish the maize if required.

The past two years have also seen a £140,000 investment in drainage, says Mr Blenkiron. “Irrigation and drainage go hand in hand. The moment you start to apply water to a crop, it must be able to move through the soil profile.”

He plans to spend £50,000-60,000/year on drainage every year in the short-term and is also putting in another 8,000m of pipework this autumn, for the new reservoir.

“We have had to make long-term decisions, due to the variability of water supply.”

Don’t let extreme weather be a drain on your farm’s resources

Paying close attention to soil drainage has allowed Forrest Farms, Suffolk, to increase yields, maintain the timeliness of field operations and get the farm’s diverse range of crops established without difficulty, even in the wettest seasons.

But just as important as investment in new drainage systems has been the ongoing maintenance of existing ones, stresses James Forrest, who points out that drainage only works well if the water has somewhere to go.

“If the ditches are silted up, or old tile drains have collapsed, problems do develop quickly. And these will carry on over a number of years, unless action is taken to put things right.”

Mr Forrest has his late father to thank for having the foresight to undertake a great deal of drainage work across the Hanslope and Beccles clay loam soil types that feature at Mowness Hall and surrounding farms.

“Most of the work, which started in the 1960s, was done when there were grants. Over time, tile drains have largely been replaced with plastic pipes, using better pipe laying equipment and new technology.”

Any problem wet patches are investigated promptly, with the help of a drainage map and a spade. “It’s often due to the deterioration of an old tile drain, which may not have been laid correctly in the first place.”

Mole draining is done every five to eight years, depending on the rotation and conditions, says Mr Forrest. “On the Beccles clay soils, the moles don’t hold as well, so we have to do it more often.”

A miraculous transformation has been seen on new land taken on under contract, simply by clearing the ditches and mole draining. “For a cost of about £100/ha, there’s been an uplift in wheat yields of 1.25t/ha. And that benefit continues in following years.”

Coping with more extreme weather events won’t be easy, despite the continual investment, he suspects. “But a good drainage system also brings soil structure benefits, which helps the water to move down the soil profile.”

With sugar beet in the rotation, he is aware that well-drained soils are needed to allow late lifting and get heavy machinery onto the land. And he points out that spring crops, which tend to follow the sugar beet, also benefit from soils that allow water to permeate them and can be cultivated at the optimum time.

“We need the widest windows to work our land,” he says. “Without good foundations, we wouldn’t have much chance to get on the land when we need to. That would compromise our rotation and our profitability.”