“We fertilize the forest because we need more biomass. The forest has the ability to bind CO2, which makes it a carbon bank. Secondly, we can use the additional timber produced for biofuel, which in turn replaces fossil fuel.”
Both scientists and governments are increasingly preoccupied with the role agriculture can play in the fight against climate change. One aspect of this is examining forests, and how increased CO2 storage capacity as well as increased biomass production can be achieved.
“The forest has the ability to bind CO2”
Erik Eid Hohle, The Energy Farm, Center for Bioenergy
"Tens of billions of dollars are being earmarked for carbon capture and storage at power stations, with the CO2 to be buried underground or under the sea. But perhaps the international community is overlooking a tried and tested method that has been working for millennia - the biosphere,” said UN Under-Secretary-General and UNEP Executive Director Achim Steiner earlier this year.
Recently, the Ministry of Food and Agriculture in Norway presented their climate report for the agricultural sector, and indicated fertilization of forests as a point of action. “Nitrogen fertilizer can contribute to increased productivity in the forest and more carbon stored in the soil,” the ministry writes in a white paper – Climate challenges – the agricultural sector as part of the solution.
In the Nordic region, fertilizing by use of helicopter has proven most effective because of the ability to cover large areas in a short period, and special fertilizers have been developed to maximize impact. This has been done for decades, especially in Sweden. The benefits for both farmers, who experience increased quality of their products, and the environment, are well documented.
Even though some N2O gas is being emitted in the process, and the fact that this is a global greenhouse gas 300 times more harmful to the environment than CO2, the net effects of carbon binding are nevertheless considerable. The IPCC (Intergovernmental Panel on Climate Change) calculates in general that 1.2 per cent of nitrogen fertilizer is emitted as N2O. Despite this, the overall effect is still a net binding of approximately 10,000 kg CO2 per hectare by using 150 kg of nitrogen fertilizer.
The Center for Bioenergy in Norway also emphasizes the positive energy output via biomass. “For every unit of fossil fuel you put in, you get 15 times more biomass, so this is probably the smartest way to use oil,” says Erik Eid Hohle.