The dollar system gives US a huge advantageMoreover their number reduced as shrinkingOn 270 luxury in the world 130 brands are FrenchExports to China and the India are reduced confirms a familiar of the French business communityFor cause the cindynique thinking is emerging in FranceThe tax valuation would be observed in 2008Let's start with that of the European UnionIt is false rebelled leader of Hermitage Emin IskenderovIn times of financial turmoil there is no shelterAsk all farmers, they answer that it is the fault of the CAP. "Our work yet show the contrary", trained the week last Guy Riba, Director General of the Inra. Since 1872, date of first agricultural statistics, the farmers were accustomed to see their plots produce more decade after decade of wheat, barley or corn. Since the beginning of the 1990s, agronomists find, alarmed, the stagnation of the yields of crops. Wheat exceeds little 6-7 tons per hectare. "Since 2000, they tend to drop" to alarm Guy Riba. A global phenomenon that FAO believes sustainable.
The institutes of research such as Inra or Arvalis eventually mobilize several bloodhounds of different disciplines in an attempt to expose the guilty. The geneticists were first picks of the finger: and if the progress of their work for selection and improvement of seed had eventually stalling For ages, farmers and scientists isolate, cross and multiply best performance individuals to create new varieties. Geneticists have a wide margin of progression before reaching the ceiling theoretical performance of 15 tonnes per hectare, calculated from the performance of photosynthesis.
Search of the suspect
Biologists have first verified that farmers continued well to use the new varieties. But statistics show that the average age of the sown varieties remained stable at seven years. They were then through the seed testing carried out each year to the laboratory for inclusion in the official catalogue. "In considering the effect of the genotype, yields continue well to increase", insists Gilles Charmet of the University of Clermont.
Geneticists have then passed the hot potato to economists. Jean-Pierre Butault of the Inra has translated the phenomenon such as shortness of breath in the overall productivity of the farms. His calculations showed that farmers do not rested on their forks. Their work productivity gain was 2 per year, far better than the industry, including through the increase in the size of the farms. Based on a study of 300 farms in the Marne, it shows that loads of farms (intermediate consumption of inputs) is also known a stability. Rest the "productivity of the land" which has necessarily declined: "yield stagnation is the cause and not the consequence of a declining productivity gains." "The CAP has only a small effect on the behaviour of farmers", slice the Economist.
Suspicion logically turned to the agronomists and their analyses of cultural practices. Philippe Gate, in Arvalis, is based on two surveys conducted in the North to kick into touch. For him, the nitrogen requirements have not increased since the 1970s, biomass (whole plant) produced by crop has stabilized at 12.5 tonnes per hectare. The treatment of diseases is not a relevant issue, comparison of yields affected plots and healthy plots showed that pests of field crops do not influence their productivity. Moreover, treatment frequency index would have decreased by 25 in ten years, confirming the downward trend in of biocides sketched by Jean-Pierre Butault.
In the end, the list of suspects includes more that a final candidate: climate. Aware of use a boilerplate become explanation, researchers have multiplied methods to confuse the guilty. The effect of the drought occurred in the regions most affected by the declines in performance. In the Southeast, rain fell by half in fifty years, as in Champagne. This explanation is also consistent with the fact that the yields of corn have been less affected than that of wheat for example. "The optimal temperature for maize is higher and intense irrigation of these cultures has offset the heat stress," explains Philippe Gate. This work of expertise strengthens researchers in coping practices and seed to climate warming. "The decline in yields shows that the natural adaptation of cultures has not been sufficient," concludes Philippe Gate.
