Corn planting has advanced by about a month, giving crops more time to grow and develop, Jacques Mathieu, head of crop researcher Arvalis Institut du Vegetal, said in an interview this week in Dijon in eastern France.
Average French corn yields rose to a record 10 metric tons per hectare (2.47 acres) last year, from 8.95 tons in 2010, according to data from crop office FranceAgriMer. The harvest is estimated at 16 million tons in 2011-12, up from 15.2 million tons a year earlier.
“We’ve advanced sowing by a month in not even 10 years,” Mathieu said. “We still have a real potential to lift yields. There’s a climate change element, but also the genetics.”
Average global temperatures are rising about 0.2 degree Celsius (0.36 Fahrenheit) a decade and this will continue for at least another 40 years based on climate-change models, according to Philippe Gate, scientific director at Arvalis.
For corn in France, “the yields continue to progress,” Gate said in a presentation yesterday at a conference organized by grain-industry lobby Orama. “In the central and northern regions, where the temperatures were sub-optimal in the past, nowadays they’re closer.”
Claude Menara, a farmer who grows corn on about 450 hectares in the Lot et Garonne department in southwestern France, plants at the end of March rather than the end of April or start of May, as he did 10 years ago.
“Global warming means we sow earlier,” Menara said in an interview in Dijon. “We’ve gained four weeks.”
A warming climate has already changed the geography of European agriculture, with a northward expansion of crops, said Jean-Paul Renoux, head of corn at Arvalis, in a presentation at the Orama conference.
“The limit for corn in the 18th century was the Lorraine, nowadays you have corn up to the Baltic,” Renoux said, referring to a region in northeastern France bordering on Germany and the Baltic Sea in northern Europe.
Climate change also has a “negative side” for corn due to an increased risk of water shortages, and warming means insect pests are spreading northward, Arvalis head Mathieu said. Longer and more intense drought conditions can interfere with nitrogen uptake by plants, corn head Renoux said.
Climate change means winter-planted wheat, barley and rapeseed in France are at a rising risk of overly dry or hot conditions, according to Mathieu. France had its driest spring in 50 years last year, cutting soft-wheat yields to 6.8 tons per hectare from 7.25 tons in 2010, according to FranceAgriMer.
“Climate change is hurting the winter crops,” Mathieu said. “If you look in the past 10 years, every year there’s been a weather mishap, it can be a summer that’s too hot, it can be a spring drought.”
Wheat has several development stages in which adverse conditions can reduce yields, Mathieu said. Climate change is keeping in check yield increases achieved by plant breeding, he said.
“There’s been a lot of progress in wheat,” Mathieu said. “With the varieties of 25 years ago we would have had a larger yield slide.”