Nitrogen, life, death
Audio 02:39
The development of nitrogen fertilizers has made it possible to explode yields in agriculture Getty Images - Caroline Gauvin
By: Florent Guignard Follow
2 min
Nitrogen is an essential element for plants.
Found naturally, it is found in the form of chemical fertilizers for agriculture.
As a result, there is too much nitrogen on Earth today, which causes pollution and endangers human health, as Claude Aubert denounces in his book
Les apprentis sorciers de l'Nitrogen
.
Advertising
They live on love, fresh water, sun and nitrogen. For plants, nitrogen is life. “
Nitrogen is quantitatively the main food for plants,”
recalls Claude Aubert, agricultural engineer.
The more nitrogen you put in, the more the plant grows and the higher the yield.
"
Nitrogen represents 78% of the earth's atmosphere.
But for most plants it is the organic nitrogen and mineral nitrogen in the soil that counts, transformed by the work of bacteria.
But with modern chemistry, at the beginning of the 20th century, we were able to create synthetic nitrogen: fertilizer, which revolutionized agriculture, with spectacular yields that feed humanity.
Until submerging the planet, as Claude Aubert regrets in the book he has just published,
The sorcerer's apprentices of nitrogen, the hidden face of chemical fertilizers
(Living Earth editions)
.
Twice too much nitrogen on the planet
“
We put too much of it, and even a lot more than the plants need,”
notes the organic farming activist.
The amounts of chemical nitrogen released each year are roughly equal to those that naturally exist in the natural nitrogen cycle. We have therefore doubled the quantity of nitrogen circulating. Some of this nitrogen is well used by plants to make them grow
; but about half is too much. This nitrogen, soluble in water, will pollute groundwater, for example.
But also the rivers. But still the atmosphere. With effects on human health.
In the form of nitrous oxide, it is also a greenhouse gas about which little was said at COP26, while it is 300 times more powerful than carbon dioxide in terms of global warming. Nitrogen can also have harmful effects on biodiversity. "
The leaves will become enriched in nitrogen, in the form of nitrates or amino acids,"
explains Claude Aubert.
These are the forms that insects, aphids and others, need. So the more nitrogen the plant absorbs, the faster the pests will develop. And since there will be more, we will have to use more pesticides.
"
Nitrogen, source of life for plants, also sows death, at the AZF factory in Toulouse in France and at the port of Beirut in Lebanon, two of the most serious industrial explosions of the 21st century, caused by ammonium nitrate .
This is the best, or worst, nitrogen fertilizer.
"Which animal lives the longest?"
"
In vertebrates, it is the Greenland shark.
Researchers have estimated the age of a female who died in fishing nets: she was almost 400 years old.
Is it the cold that preserves?
Rather, its secret to longevity lies in its very - very slow growth: the Greenland shark only grows one centimeter per year.
Everything takes time in this polar water animal: it moves at a record speed of less than 2 km / hour.
And he does not reach sexual maturity until 150 years old.
When we die, they are still children.
Newsletter
Receive all international news directly in your mailbox
I subscribe
Follow all the international news by downloading the RFI application
google-play-badge_FR
Flora