GLOBAL - Nitrogen use in agriculture keeps two billion people alive and costs the US economy over two hundred billion dollars a year, according to a growing body of research.
Studies have tried to monetise the benefits and costs of Nitrogen, with a recent paper arriving at an average per hectare per year figure of $252 for the cost of Nitrogen leakages into US fresh water.
However, figures on Nitrogen’s detrimental side vary hugely, depending on costs to human health, ecosystems, climate and farming.
A paper in Environmental Research Letters in February stressed the challenges in accurately gauging the cost of leached Nitrogen, particularly from algal blooms and consumption of contaminated water.
As a result of this, the cost for Nitrogen in the US ranges from $1.94 to $2255 per hectare per year.
The role Nitrogen plays in crop performance and food security was illustrated in a 1997 study which claimed one third of the world’s population would not be alive without synthetic Nitrogen fertilisers.
While higher productivity from the land is a key benefit of applications, Nitrogen costs the EU an estimated €35-230 billion/year and benefits farming to the tune of €20-€80 billion per year.
For farmers, there is pressure on both synthetic nitrogen fertilisers as well as a host of regulations on the spreading and handling of animal slurry.
Heavy fines are levied by US governments to dairy farms every year. An Environmental Protection Agency calculation from 1998 calculated the extent of river impairment at over 170,000 miles – 70 times that of the Mississippi river.
In terms of dairy cow manure, a 200 cow US dairy farm is equal to that of a settlement of 5,000 to 10,000 people.
This figure was delivered by the US Department of Agriculture Natural Resources Conservation Service, which, in 1995, followed up the above fact with the statement that “any increase in animal numbers results in an equal increase in the problems arising from manure collection, storage, treatment and utilisation.”
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