Podcast: Climate change and potatoes

Tractors ploughing a field

Potato planting

18 February 2015 by Richard Hollingham

This week in the Planet Earth podcast, Ruth Welters of the University of East Anglia and potato farmer Johnnie Jiggens explain how environmental science can help the agricultural sector plan for future weather extremes.

To assist those who find text-based content more accessible than audio, a transcript of this recording is available below.

Richard Hollingham: Chipped, baked, roast, diced, crisped or mashed: in the Planet Earth podcast, what effect will climate change have on Britain's favourite vegetable, the potato. I'm Richard Hollingham and in National Chip Week I have come to an arable farm in Essex where potatoes are one of the main crops. And you really have to feel for farmers on a day like today, it's a bleak winter's morning and we're surrounded in the farmyard by the flat Essex countryside and then beside me a series of metal-clad barns surrounded by wooden crates - more on those in just a moment. Johnnie Jiggens owns this farm and I am also joined by Ruth Welters from a new NERC-funded project called Agritech Water Cluster. Now, before we talk about potatoes, Ruth, what is Agritech Water Cluster?

Ruth Welters: So, the Agritech Water Cluster is based at the University of East Anglia in Norwich and we really want to work more closely with farmers and other business people in the Anglian region to bring some of our research a bit closer to the things that they need to know on their farms.

Richard Hollingham: And you're particularly concerned long-term with climate change?

Ruth Welters: We've got expertise on soils. We've got people who work on rivers and water. We've got people who very much focus on weather and of course we've got people who look at long term climate change and do modelling predictions for how climate might change over the next fifty years.

Richard Hollingham: Now we're going to talk in a moment about how that's related to potatoes, but there is a barn here full of them. Can we go inside?

Johnnie Jiggens: By all means. Come in.

Richard Hollingham: So, through the roller door and into the barn itself and this is stacked floor to ceiling with wooden crates and each of these wooden crates is full of potatoes.

Johnnie Jiggens: It is indeed, yes. So each potato box, we call them, stacked in this store are six high and each should hold one tonne of potatoes.

Richard Hollingham: Okay. That's an awful lot of potatoes. Let me just rummage through this crate which is down on the floor. They all look pretty perfect, actually. They are about tennis ball size potatoes and so this is just one box absolutely packed full of them and the whole barn is full of potatoes.

Johnnie Jiggens: It should hold about 900 tonnes when it is full. I would like to think they are perfect potatoes but I can't always guarantee we grow the perfect potato but we certainly try.

Richard Hollingham: And where will these end up?

Johnnie Jiggens: This specific potato is actually leaving the farm today and it is going to be packed up to go off to the Canaries. It will actually be sold out in the Canaries in a 25 kilo bag straight off the shelf in their supermarkets and it will be for the people from there.

Richard Hollingham: So how have you got involved with scientists? What can they bring to farming?

Johnnie Jiggens: Well in this specific research, obviously about water, and that is pretty critical to growing potatoes for many elements. Obviously, originally, it was probably brought about back in the seventies when irrigation started to bump up the yields. Yields would have been in almost, probably, single figures apart from the years when rain fell at the right time.

Richard Hollingham: So more rain, more water, more potatoes? It's as simple as that?

Johnnie Jiggens: Yes, effectively. Now, very much, it is now for quality, be it skin finish of the potato. We also use water in certain years at harvest to keep the skin quality so they don't rub on the machinery, and then ultimately it is also critical on yield.

Richard Hollingham: How much of one of these potatoes is water?

Johnnie Jiggens: The dry matter would be something in the region of 20% to 24% I believe, so you're talking about 70/75% plus water.

Richard Hollingham: Ruth, when we're talking about water and the importance of water for potatoes how is that related to climate change?

Ruth Welters: We're interested in, obviously, helping farmers with some specific research if we can, but we're also very much interested in water use in the broader environment. So we're interested in there being water for agriculture, water for the rivers and for our wetlands in the eastern area and also, obviously, the other big use of water is the water company. We really want to try to help all of these people understand just how much water is there now and how that might change in the future, how that might affect their businesses and how we can start to plan for that and to see how that might change both in the near future and over the longer time up to about fifty years time.

Richard Hollingham: And what are the predictions for water related to climate change and the change in weather patterns, I suppose?

Ruth Welters: So, generally, in the whole country the predictions are it will get slightly warmer and slightly drier and of course in the East Anglian region we're feeling it here, even now, and that will become more extreme here - that's the prediction. The other thing, of course, is it's not just a steady increase to slightly warmer, slightly drier, it's that there is a lot of variability and we've seen that and I'm sure you've experienced that yourself Johnnie in the past. In the past couple of years, especially, it really depends on when that rain falls and how much you can store on your farm and how much is available. The other side of the research is in the shorter time scale and the people who work on weather forecasting to try to increase their accuracy in small spatial scale and shorter timescale, so that you might be able to say, yes it will definitely rain tomorrow in my field.

Richard Hollingham: Now, I've covered farming issues, environment issues for a number of years and when you talk to farmers the weather is never right.

Johnnie Jiggens: Yeah, I don't think you will find a farmer that is happy about whatever weather we are having, but it is very difficult to predict the weather. I've noticed the weather forecasters, and I'm not accusing anyone, but it certainly hasn't seemed to be as accurate and quite often you will be told you are going to get, for example, 20 millimetres of rain the next day, so the ideal thing would be to turn the irrigation off or to stop it and if that irrigation doesn't come you've suddenly lost 24-hours of potential watering of the crop and it puts you back, and if you then have a spell of a week, two weeks dry period after that you are forever chasing yourself with getting water onto the crop.

Richard Hollingham: So water is crucial and that's the weather, but what about climate. What is farmer's attitude to climate change and these long term predictions being told 25 years along, 30 years along, 50 years, 100 years, does that help farmers?

Johnnie Jiggens: Yes, I mean it has got to be helpful for future planning. It is more these spells of long dry periods, which is when the irrigation becomes critical. The last few summers have been quite nice but we've also had, especially it seems to be weekends, where it has done nothing but rain. So in my case I would happier at the more accurate predictions of the weather. Whether we're warming up... throughout the world we may be but are we in England, I'm not so sure.

Richard Hollingham: So, Ruth, you've got a challenge here to work with farmers to try and convey that the climate aspects of this. It sounds like you can sell the idea of more accurate weather but selling a long term climate prediction is harder.

Ruth Welters: Yeah, and it is also for us to understand really about what the time scales that farmers do plan on and I think maybe at the start of these projects we thought everyone needs to know a fifty year prediction and maybe for certain businesses but that's not true. For the other businesses that we work with, for example, Anglian Water, they are planning on a 25-year timescale, so that data may be of more interest and of use to them. So we're not trying to convert people but we're just trying to start a conversation to say... for us to understand as much as for other people to understand what are the risks and what sort of timescale are we trying to work on.

Richard Hollingham: And what about changes of crops. Assuming farms are still in this part of England in fifty years time, might farmers have to start thinking about different uses of water or change in crops even.

Ruth Welters: So that's something that at a workshop we held we really tried to get a feel for people who are really trying to plan ahead, so are they putting water storage on their land, are people looking at drip irrigation and all these other innovations, and I think it really does depend on the crop. So, for example, maybe in the horticultural region, so that would be much further up north towards The Wash, maybe people are more thinking about these enclosed systems where they can capture and reuse all the water. Obviously that doesn't make sense for potatoes. So it really does depend on the crop. We're interested and that is some of our work to try to model where crops are grown now and how, if the climate changes in the way that we do predict, whether we will shifts of those different crops grown in different parts of the country and maybe some of the crops we grow here now won't be able to be grown here in fifty years time. But we're not in a position to say that for sure, we're just starting to look at that now.

Richard Hollingham: Now, Johnnie, you are third generation farmer in this area, actually on this farm?

Johnnie Jiggens: Exactly, yeah.

Richard Hollingham: You're obviously got a sense of the past and what's been farmed here and you can talk to your father, grandfather, whatever, of what's been farmed. What about the future? Are farmers good... are farmers good at thinking ahead and thinking how we might have to plan for water use in the future, particularly if you're going to carry on growing something like potato which uses quite a lot of water.

Johnnie Jiggens: You always plan a year or two in advance from just a crop and rotation and areas such as that, but we've invested on our farm heavily in water storage over the last... probably going back twenty plus years but only two years ago we put a new ten million gallon reservoir in, so extra storage there for winter storage of water, and that will allow us to irrigate potentially another sixty, seventy acres of potatoes throughout the summer. So that secures water for us. All these capital investments obviously, clearly, cost money and you've got to have the returns to be able to invest in the future.

Richard Hollingham: Johnnie Jiggens, thank you very much for inviting us to your farm and Ruth Welters from Agritech Water Cluster, thank you as well. I will take some pictures of the farm here and stacks of potatoes which we will put on the Planet Earth Online Twitter feed which is Planet Earth News and also on our Facebook page. So, Johnnie, the next stop for these and these will be picked up in just a moment, is the Canary Islands?

Johnnie Jiggens: It is indeed, and these will be collected very shortly and taken off the grader, bagged up into 25 kilo bags, stacked on pallets and loaded on a container ship on Wednesday, I believe, early Feb for sale in the Canaries if you are on holiday there.

Richard Hollingham: For more news from the natural world, do visit Planet Earth online where you will also find all our past podcasts now going back more than six years. That's the Planet Earth podcast from the Natural Environment Research Council. I'm Richard Hollingham and from the farm here in Essex as they load up more potatoes onto the tractor, thanks for listening.