Wednesday, August 28, 2013

Chicken and fertilizers

Dolly Partons sings:
We've got chicken every Sunday and the preacher comes around
And every Saturday morning daddy takes us all to town

Today "Sunday Chicken" is no institution. Chicken is everywhere and in all shapes. And it is dead cheap. 

We eat chicken because of chemical fertilizers. Let me explain how & why. And why it might not be such a bargain in the end...

Historically livestock was fed on grass, silage and hay, all crops that can’t be eaten by humans. Small quantities of pigs and chicken, who largely eat the same as humans and don’t grow well on grass could be raised on waste products or seek their own feed in the farmer’s yard or manure heap – a very popular place for chicken. Historically this meant that pork and chicken were expensive. The tradition of “Sunday chicken” is an expression of this. Expensive and rare foods were eaten on the Sunday. 

With the introduction of chemical fertilizers, farmers could specialize in grain production and the proportion of land in grain as well as the yields increased a lot. This in turn allowed for even more mechanization, so that grain production use very little labor. The essence of this is that grain now has become very, very cheap in a historical perspective. And it is in light of this we should see that chicken consumption has increased five times in hundred years in the USA and ten times in Sweden, while beef consumption is more or less stable[i].

Nitrogen fertilizers give a tremendous boost to growth. According to the European Nitrogen Assessment[iii], synthetic N fertilizer has been estimated to sustain nearly 50% of the world’s population, but its use comes with a very big prize tag. The report states that the increased level of reactive Nitrogen in the biosphere might represent the greatest single experiment in global geoengineering ever made. 

In one of the most influential scientific articles last decade, ‘Planetary boundaries: Exploring the safe operating space for humanity, professor Johan Rockström and colleagues identify the nitrogen cycle as one of three areas - together with climate regulation and biological diversity - where human beings have surpassed a threshold for stable development. The quantity of biologically active nitrogen released annually into the biosphere has increased ninefold in 100 years, and it is projected to continue from 165 million tons in 2000 to 270 million tons in 2050 (MEA 2005). 

From the perspective of the individual farmer the use of Nitrogen fertilizer is profitable. The return of one euro invested in nitrogen fertilizer is estimated to between two and five euro. But someone else pays a bigger bill. Without knowing it, if you are a European, you might bear costs of over €500 per year for farmers’ use of Nitrogen fertilizers. “Environmental damage related to Nitrogen effects from agriculture in the EU-27 was estimated at €20–€150 billion per year. This can be compared with a benefit of N-fertilizer for farmers of €10–€100 billion per year, with considerable uncertainty about long-term N-benefits for crop yield”  says the European Nitrogen Assessment.

Overuse of nitrogen fertilizer is no European specialty; it is the same or worse in many places. In the US the Mississippi, the Columbia, and the Susquehanna rivers together discharge approximately 1 million tons of nitrogen in the form of nitrate per year to coastal waters according to a report from H. John Heinz III Center – this corresponds to about one tenth of the total quantity of nitrogen applied[iv]. In Rwanda, erosion causes loss of almost 1 million tons of organic matter, some 40,000 tons of nitrogen, 280 tons of phosphorus and 3000 tons of potassium—more than the total use of chemical fertilizers according to the Ministry of Agriculture. 


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