East Anglian conference: Is climate change a double-edged sword for farmers?

Bill Clark, Commercial Technical Director at NIAB

Bill Clark, Commercial Technical Director at NIAB - Credit: Archant

The wildly contrasting weather of 2012 made it a dismal year for food production. And the Norfolk Farming Conference later this month will hear that our changing climate could bring yet more challenges for the region’s farmers in future – but also some opportunities.

Dr Clare Goodess, Senior Researcher at the Climatic Research Unit

Dr Clare Goodess, Senior Researcher at the Climatic Research Unit - Credit: Archant

From drought to deluge, and from snowfalls to floods – even by its own fickle standards, the British weather set a new benchmark for unpredictably during 2012, making life extremely difficult for East Anglia’s farmers.

Prayers for rain to revive arid soils after an 18-month drought were finally answered in spring, but the over-zealous cloudburst took us from one extreme to the other, and into one of the wettest summers on record.

It was a disastrous combination for staple crops like wheat and vegetables, with fields flooded, crops washed out and yields damaged.

And the vagaries of our weather are expected to become even more pronounced in future, with climate change predictions suggesting winters becoming wetter and summers becoming drier.

That could present a host of obvious challenges to agricultural productivity – but it could also bring some new opportunities.

The impact of climate change and the roles which new technology and science will play in the future of food production will be among the topics discussed at the Norfolk Farming Conference in Norwich on February 21.

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Speakers will include Dr Clare Goodess, a senior researcher at the Climatic Research Unit at the University of East Anglia, who will outline the challenges of the changing weather. She said there have been a series of “statistically significant” trends recorded in the East of England between 1961 and 2006, including a 1.8C increase in mean daily maximum temperature, and a steady reduction in the number of frost days.

Climate analysts see those trends continuing into the future, accompanied by more pronounced extremes in the hottest days of summer, and severe rainfall events in winter.

But while drier summers would increase demand for irrigation, water and wetter winters could increase flood risks. Dr Goodess said the damaging effects of a warmer climate could be partly mitigated by positive changes in wheat and sugar beet yields and opportunities to grow new crops.

Meanwhile, it is thought that increased concentrations of atmospheric carbon dioxide (CO2) could aid photosynthesis, the process through which plants convert CO2, water and sunlight into chemical energy for growth.

Dr Goodess’s suggestions were echoed by Bill Clark, commercial technical director at NIAB (the National Institute of Agricultural Botany, based in Cambridge), who will also be addressing the conference.

He said: “That’s the case with sugar beet yields. It’s the main reason why sugar beet yields have been going up in the past 10 or 20 years. If growers sow too early the seedlings are exposed to these low temperatures and produce a flower head and not a root, so you don’t get any yield from that plant. If it is warmer in spring then you can sow earlier and the risk of it going to seed or bolting is reduced.

“Climate change is a very positive thing for sugar beet, but for other crops it is a very mixed picture. One of the things we have been concerned about is the effect of very high temperatures on flowering in wheat.

“One of our targets is to look at varieties with heat tolerance. It usually means bringing the flowering period forward so it flowers before the very high temperatures. But that can then shorten the grain-filling period. It is not black and white.

“In general, climate change for arable crops will have a negative effect. That is in a situation where we are talking about global food insecurity and where, particularly in Europe, we are talking about trying to increase yields against a backdrop of European legislation forcing yields down.”

Mr Clark said many of the difficulties facing the region’s agriculture were linked to agronomic and technological factors – but, in one of the driest regions of the country, the potential for increasing yields would always be governed by the availability of water.

“Wheat yields have been static for 15 years on farms,” he said. “One of the factors is whether growers are actually growing the highest-yielding varieties. They grow the varieties they are comfortable with, and the ones they know how to grow.

“Farms are also getting bigger and so it becomes slightly more difficult to maintain individual crops. It is very difficult for large farms to optimise their timings for phosphates and nitrogen. In trials we can do that, so yields are going up in trials – but they are not going up on farms.

“From an agronomic point of view, optimising inputs is a real challenge, but even if farms optimise all their inputs, yields will still not go up quickly enough.

“To grow a 10-tonne crop of wheat, which is not unusual per hectare of good land, that crop needs 500mm of water per year. So it takes half a tonne of water per square metre to produce 1kg of wheat. If you want to double your yields from 10 tonnes to 20 tonnes you need twice as much water, 1,000mm per year, and we don’t get anything like that in the East. So the answer is not just genetics. High-yielding crops cannot be the answer on their own, because we don’t have enough water.

“A combination of plant breeding and agronomic research should allow farmers to raise yields above those currently achieved. But it is a complex scenario, especially in places like East Anglia where water is the limiting factor.”

UEA climate researcher Dr Goodess said the unpredictable weather of the past year was at odds with the recorded annual trends.

“We had a very dry winter with drought conditions in spring, followed by a very wet summer, so what has happened over the past year is very different to the seasonal pattern of dry summers and wet winters,” she said.

“Making sure we capture the winter rainfall is going to be essential in future so that it is available during the summer. The bottom line is that the threats and the negative opportunities seem to outweigh the positive. There will be decreases in frost days which could potentially have a negative impact on some types of agriculture.”

Prof Dale Sanders, director of the John Innes Centre, which is hosting the Norfolk Farming Conference, will give delegates an insight into the centre’s latest plant science research and the benefits it could bring to the agricultural community.

He said: “Instead of struggling with yield grains of half a per cent, can we jump to five per cent and more? Can we do this at the same time as reducing pollution and agriculture’s contribution to global warming, while also adapting crops to the extremes of weather wrought by climate change?

“Science can help achieve goals that seem impossibly conflicting. What we achieve in the UK can inspire and benefit farmers, breeders and researchers the world over.”