The soil or earth is the superficial part of the earth’s crust. It is a thin layer that is biologically active and is formed by the accumulation of minerals, organic matter and small living beings. The interaction of all this makes it possible for life to grow and therefore, the birth and growth of vegetables. This optimal condition forms in hundreds or thousands of years and its nutrients can be depleted. Hence the concern to replace them in agriculture is born. But it is not always done in a conscious and respectful way with nature, which involves many problems for global health today. This is what happens with the use of so-called chemical fertilizers.
Origin of chemical fertilizers
At the beginning of agriculture, the methods to provide the land with nutrients were various, but all of them were based on ecological cultivation techniques such as the replenishment of nutrients through manure, crop rotation, fallow, etc. The problem of modern chemical fertilizers developed with the arrival of the nineteenth century, in which there was a great need for supplies to industry and cities, causing the acceleration of consumption. From then on, ways were sought to restore the nutrients of the earth without respecting the times of the soil in its natural renewal capacity.
It was in the early 20th century that two German chemists, Fritz Haber and Carl Bosch, developed a procedure to use nitrogen from the air and fuse it with hydrogen, which would result in liquid ammonia. This would be the key ingredient in synthetic fertilizers thanks to which an agricultural expansion would develop that has not stopped growing. Such was the scientific advance that both received the Nobel Prize. But although this discovery would help feed a world in constant growth, it would in turn suppose the pollution that leads us to the crisis of environmental sustainability that we live in today.
In addition to consumption, environmental phenomena and environmental problems that we suffer today, prevent the cultivation of food from being done under normal conditions. Because of these effects and the multiplication of production, natural production processes have been replaced by artificial ones in which chemical substances are present.
Problems of chemical fertilizers
Although the discovery of liquid ammonia was key to agricultural expansion, the last 100 years have had a far from positive effect: the amount of man-made nitrogen compounds in soil, air and water has doubled. But why does this fact present a problem if nitrogen is essential for life on earth? Because in excess it is a dangerous pollutant that accelerates climate change through emissions of nitrous oxide, a potent greenhouse gas. In turn, in excess, it poisons water, animals, plants and humans. For all these reasons, according to experts, it is currently one of the most serious threats to humanity.
At the beginning of the 19th century, there was almost no presence of artificial nitrogen compounds in the environment, but with the advance of Haber and Bosch, levels skyrocketed due to synthetic fertilizers, the manufacture of munitions and the burning of fossil fuels. According to IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services), nutrient runoff from farms and the mixing of these synthetic fertilizers are the main negative impacts on terrestrial ecosystems today.
This puts the environment and human health at risk, for example by the combination of agricultural ammonia emissions and vehicle emissions, which create particles that are hazardous in the air, causing respiratory diseases. Also because everything that harms the soil in which we grow the food we eat affects our health. For this reason, we insist on the urgency of raising awareness and promoting the need for organic farming or techniques that are not harmful to the soil.
According to the UN and its United Nations Environment Program (UNEP), the solution is to stop this toxic flow and that is why, together with some governments, companies and international organizations, they have been collaborating with science to analyze the problem, the risk involved and look for possible solutions. From this was born in 2019 the Colombo Declaration calls for tackling global Nitrogen Challenge through which they warn of the need to reduce nitrogen waste by half by 2030.