Throughout the history of the human species, there have been innumerable inventions and discoveries that have left an indelible but often unappreciated mark on history. Many of these discoveries, like paper, the compass, and the clock changed the course of history and have allowed humans to achieve new levels of greatness. Though today, these discoveries are often seen as commonplace and their contributions to human achievement go underappreciated.
At the turn of the 19th century, farmers fertilized their crops using the same methods that had been used for hundreds of generations; namely, manure and compost. While this was sufficient to meet the basic needs of the plant, fertilization was random in both the placement and amount of nutrients and crops tended to have low yields (i.e. less than 25% of today’s yields). Production was quickly falling behind the demand of ever growing urban populations.
Something needed to be done and great minds around the world began searching for a way to increase food productivity; they were searching for something new, something to advance agriculture and push food production to new heights.
Enter synthetic fertilizer; the invention that feeds the world.
The history of nitrogen based fertilizers begins back in 1909 with the Nobel prize winning discovery of the Haber-Bosch process, a technique which pulls nitrogen from the air and mixes it with hydrogen and methane to produce ammonia – the main ingredient in nitrogen based fertilizers.
However, the process was hijacked by the war effort which was hungry for ammonia needed in munitions. Driven by the WWII, ammonia production around the world took off as the Haber-Bosch process was fitted for mass production, with 10 large industrial ammonia plants in the USA alone by 1944.
When the war ended several developed nations were perfectly situated to begin the mass production of synthetic nitrogen based fertilizers as production switched from munitions to fertilizer.
Fortuitously, the mass production of fertilizer led to massive increases in food production which coincided with the post-war baby boom, though it is a bit of ‘the chicken or the egg’ situation.
With the world’s population doubling between 1900 and 1960, from 1.6 billion to 3 billion, the agricultural community became increasingly dependent on synthetic fertilizers to produce enough food to feed the world’s growing population.
Nearly sixty years later, with a current world population of 7.3 billion, the situation hasn’t changed – farmers are still dependent on synthetic fertilizers to produce adequate amounts of affordable food.
It’s hard to deny the significant role synthetic nitrogen based fertilizers play in feeding the world.
As stated by Vaclav Smil, professor emeritus from the University of Winnipeg note, “With average crop yields remaining at the 1900s level the crop harvest in the 2000s would have required nearly four times more land and the cultivated area would have claimed nearly half of all ice-free continents”.
With the UN projecting the world’s population to reach 9.7 billion by 2050, the world will continue to rely on synthetic fertilizers to produce even more food without claiming even more land for cultivation.
Now, keeping in mind the role of fertilizer in feeding the world, there are growing concerns about the ever increasing quantities of fertilizer applied to the land. Only 50 -70% of the N applied to the land gets taken up by the plant, the remainder is lost in various ways.
Nitrogen and phosphorus are known to leach from the soil into waterways, interrupting the natural biological systems by fueling the overgrowth of aquatic based plants (i.e. a process called eutrophication). Algae blooms are also associated with leached nitrogen, which on a small scale, can turn swimming areas into an unpleasant green soup, but on a large scale can actually deplete oxygen levels in the water resulting in large killoffs of fish, particularly in shallower waters.
While the use of fertilizer has undoubtedly allowed us to sustain our ever growing population, these growing environmental concerns along with the increasing cost of fertilizer mean farmers are searching for more sustainable ways to get the necessary nutrients in the ground.
The future of fertilizer is optimization.
Improved farming practices, like multi-year crop rotations, minimum-till seeding, and cover crops work to improve soil health through more natural processes. Ultimately nutrient needs are determined by the plant but healthier soil generally requires less maintenance thus reducing the quantity of synthetic fertilizer needed.
Technologies like variable rate fertilizer application and improved soil sampling are helping farmers to make the most of the synthetic fertilizers that are used. Advancements in soil testing and precision application technologies (e.g. variable rate fertilization), mean that the right quantities and types of fertilizers are applied exactly were they need to go.
New innovations like slow release fertilizers which break down as the plant needs nutrients, or nitrogen inhibitors, which bind nutrients to the soil are being used to prevent nitrogen losses through leaching, denitrification and volatilization. And new types of fertilizer supplements, like biologics which inoculate the soil with beneficial microorganisms that transport or trap nutrients (e.g. AMF/mycorrhizal fungi), are continually being developed.
While the Haber process fundamentally changed agriculture, it is unlikely that the next stage in the evolution of fertilizer will be spurred by a single innovation. Instead, it will likely be a number of smaller, non-Nobel prize winning innovations and optimizations that will take agriculture to the next level and allow the world to feed it’s ever growing population.
Smil, V. 2011. Nitrogen cycle and world food production. World Agriculture 2:9-1.PDF
U.N. Report, 2017. World Population Prospects. https://www.un.org/development/desa/publications/world-population-prospects-the-2017-revision.html