The seabirds saved by synthetic chemistry

Agriculture was ripe for revolution. Europe’s population had doubled over the 100 years to the mid-19th century and could double again over the next 100 – if food production kept up. A huge increase in the area under cultivation had driven this growth, but land was running out. Farmers needed new tools; they needed new ways to increase agricultural output.

On a farm in Alsace, nestled against the German border, French chemist Jean-Baptiste Boussingault came up with a solution. His experiments had proven beyond doubt that farm output depended on one element above all others. He had seen it in his fields; had measured it in his lab: the more nitrogen he applied, the greater the yield from his crops.

To add nutrients to their soil, farmers relied on the recycling of organic waste. Straw and animal manure – up to 20 tonnes per hectare – were commonly applied to fields around Boussingault’s farm. But food and nonrecycled waste removed nitrogen from the ecosystem and it could only be replenished by rotating high value crops with low-yielding (but nitrogen-producing) legumes. Which led Boussingault to a clear conclusion: to increase productivity, farmers needed to find new sources of nitrogen.