Water, water, everywhere...

It takes over 17,000 litres of water to produce just 1 kg of chocolate.

That's one of the startling figures compiled in a new report on food waste by the Institution of Mechanical Engineers in the UK.

The report: Global Food - Waste Not, Want Not; made the news last month because of the headline-grabbing figure of 50%. That's the proportion of food wasted worldwide without ever reaching a human stomach.

The figures for water usage in the report come from the Water Footprint Network and make for stark reading when tabulated (see below). For example, it takes 822 litres of water to produce 1 kg of apples.

On average, 1 kg of beef takes 15,415 litres of water to produce and one cup of tea takes 27 litres.

The various wasted inputs (water, energy, agrochemicals, etc.) associated with wasted food is often not considered by consumers but, as the report states: "[the 50% headline figure] does not reflect the fact that large amounts of land, energy, fertilisers and water have also been lost in the production of foodstuffs which simply end up as waste".

Water use in agriculture (Source: Global Food - Waste Not, Want Not)

According to a recent European Environment Agency (EEA) report on water use in Europe, agriculture accounts for 33% of total water use. That figure can go as far as 80% in parts of southern Europe where irrigation of crops is essential and accounts for almost all agricultural water use.

In the clamour for higher yielding varieties of crop plants for agriculture, it makes sense to stop and think about how current yields are squandered and how limiting resources such as water and energy and thrown in the bin.

You can read the food waste report here.

You can read the EEA report here.

I write more on the issue of food waste, the global future of crop production and precision agriculture in the Spring edition of Walton Magazine, which is out now.

Image: Watering Crops by Margaret W. Nea. Creative Commons