What about agriculture? Insights from the past
Barley, wheat, potatoes and sugar beet are among the most produced crops in the UK.
- Barley production peaked around the 80’s, it significantly decreased until 1994 and then it almost stabilized around 6 million tonnes per year.
- Wheat shown an exponential production increase from the 60’s to the 80’s and then it remained nearly constant around 15 million tonnes per year.
- Potatoes didn’t experience a significant positive trend in any period, differently from barley and wheat, but it barely decreased of 1 million along the whole period.
- Sugar beet production peaked 10 years later than barley and wheat, achieving 11 million tonnes in 1997 hence reaching the barley peak of 1984.
Water use efficiency
Crop water footprint has decreased substantially over the past decades, mostly driven by enhanced yield. Hence, less water is required to produce a tonne of crop.
- Barley and wheat water footprint halved in the 80’s thanks to a linear increase of their yield.
- Similarly, potatoes water footprint significantly decreased up to the 90’s. Importantly, it shows the largest decreasing rate.
- Sugar beet water footprint linearly decreased in the past and it’s keeping on with the same trend nowadays.
- Notably, potatoes and sugar beet present a water footprint 10 times lower than wheat and barley, on a overall average.
The total water footprint varied in the past years mainly following the patterns of production and cultivated areas.
- Wheat and barley total water footprint clearly overlapped the trend of production.
- Conversely, potatoes total water footprint decreased faster than production, thanks to the halving of cultivated lands.
- Sugar beet total water footprint almost remained constant around 70 million cubic meters per year and then sharply decreased to 40 million cubic meters per year in the 2000’s.
The risk of external water dependence
- UK is a net importer of virtual water, namely it relies on external water resources for its domestic consumption
- Major flows come from Netherlands, Germany, and France
- Nearly 50% of the UK’s global water footprint is located in regions where water resources are over-exploited [Hoekstra et al., 2016, ERL]. See Spain below.