Strawberries, polytunnels, carbon

Strawberries exceptions to the rule?

Does increased yield, quality and reduced agrichemical useage lead to a reduced carbon footprint for strawberries grown in polytunnels compared to those grown outdoors? In seems not, recent analysis by 383ppm for a major strawberry producer produced an interesting conclusion.

Surprisingly, despite a greater yield per hectare strawberries grown in polytunnels have higher carbon emissions than those grown outside (78g of CO2 per kilo versus 17g of CO2 per kilo for Class 1). Our data and scope were limited but this disparity between the two production methods are so great that we don’t expect the inclusion of future data to change the overall conclusion. In hindsight perhaps it’s not so surprising - strawberries are relatively light and the polythene used for polytunnels is heavy with the embodied carbon you’d expect of a material made from crude oil.

Some ideas - use renewable alternatives to polythene or materials which don’t need to be replaced as often.

Amjad Karim, 26th January 2011