Heading north: the great crop migration

My job is full of numbers. Yields, areas, quotes, temperatures... all take a big chunk of my working day. Most of these figures are predictable. Yet every once in a while, something really unexpected comes into focus.

Scandinavian oddity
This is exactly what happened a few months ago, when I entered for the second year in a row a corn production in Sweden. That piece of information puzzled me. In fact, had it not come from an official source, I would have believed it to be a mistake. Even if corn is grown on a very large scale in countries such as the US, it remains a tropical plant, not well adapted to the coolness of Swedish summers.

Though strange, the few thousand tons of corn produced in Sweden were not revolutionary enough to keep me awake at night. I would probably have forgotten the issue if I had not stumbled across an odd article barely a week later; it described the truly impressive growth of corn acreage in Denmark. As was highlighted in the paper, corn area totalled a mere 20,000 ha at the beginning of the nineties. In 2008, it had risen by almost ten folds. At the same time, the optimal sowing date for the crop had moved backward, from May 1 to April 20. Ten days in twenty years may seem anecdotal, but for an agronomist, this equals to a flashing red light: something is going on there!

Heading north
Quite excited, I decided to have a serious look at the corn data I have for Europe. Here is what I found:

Source: various national statistics offices. The data include both corn for silage and for grain.

In the northern fringe of Europe (namely Denmark and Poland, but also Sweden or the Baltic states), corn acreage has increased very sharply between 1995 and 2009. This also holds true in Germany, where the area allocated to the crop has gained 500,000 ha since 1995. However, as the German area was already quite high in 1995, this implies a smaller change in proportion than in other countries. On the other hand, corn area has stabilized or even decreased in countries of southern Europe (Italy, France, Slovakia, but also Spain or Hungary).

Without too much head scratching, I could thus easily see two things: first, that there seemed to be consistent changes in corn acreage happening both in the north and in the south of Europe. Secondly that situations in the south and in the north seemed to be opposite. As both the north and the south of the European Union are submitted to the same agricultural policy (the CAP), I was left with a growing suspicion that these contrasted changes may well be linked to climate. At this point, I decided to call one of the most prominent specialist of cereal physiology in France and get his point of view on the matter.

My story did not seem to surprise him much; in fact, it corresponded to what he had been monitoring for years. Agricultural species are moving north, as farmers take advantage of a wider growing window - the gap between sowing and harvesting dates. For a plant such as corn, the growing window is long (at least five months). In countries like Sweden, where summers are cool and winters come early, the long growth cycle of corn had until recently prevented any major development of the crop because the plant would not be able to perform its entire growth cycle before the frosts. Yet, as this drawback becomes less important, farmers in northern countries have started introducing the crop onto their farms...

Southern worries

Image: Tuscany

This explanation left me with one serious question: what would happen in southern Europe? If the growing window tended to increase in the north, one would expect that crop development in the south might be more frequently hampered by less auspicious weather events, such as droughts or hot spells. According to my own observations, this already seemed to be the case in several European countries located along the Mediterranean rim, where the area left fallow showed a tendancy towards increasing.

After I had expressed my concerns, there was a deep silence at the other end of the phone line. "This is a real issue, I was finally told. It is very likely at this point that future weather conditions in the south will exceed the adaptive capabilities of a species like wheat. Farmers will probably have to turn to more drought-resistant species. Who knows? In 2030 or 2040, farmers in Italy may well choose to grow sorghum or millet instead of durum wheat..."

If this turns out to be the case, then it is really worth wondering what farmers of more southerly countries, such as Mali or Niger, will be left to cultivate. Millet and sorghum both constitute staple food in Africa today. If these crops move north, answering this particular question might indeed become one of the most important issue of the coming years. If not of the century.

Version française : la grande migration agricole