Nicknamed the teardrop of India for its distinctive shape, the island of Sri Lanka off the southeast coast of the subcontinent has dug itself into an economic hole. In April of 2021, Sri Lanka’s then-president, Gotabaya Rajapaksa, banned synthetic fertilizers and agrochemicals (pesticides and herbicides) forcing farmers to use organic fertilizers in the attempt to build a country more “in sync with nature”.
For decades, Sri Lanka had been importing and subsidizing synthetic fertilizer, leading to great success in exports such as rice, tea, and rubber. In 2020, the cost of these imports and subsidies amounted to hundreds of millions of dollars per year. So apart from wanting to come off as a “natural” man, Rajapaksa really wanted a budget cut.
Besides carbon dioxide from the air, plants require the presence of nitrogen, phosphorus and potassium compounds in the soil for growth. Synthetic fertilizers typically have nitrogen in the form of ammonia (NH3) or its derivatives, urea, or ammonium nitrate as a base. Ammonia is produced by the Haber process, which allows hydrogen (produced from natural gas) and nitrogen from the air to combine with the aid of iron acting as a catalyst to speed up the reaction. Continual recycling of unreacted nitrogen and hydrogen allows 98% of these reactants to be converted into ammonia. But production of ammonia is an energy-intensive process and is plagued by the emission of carbon dioxide, a greenhouse gas. Synthetic fertilizer also contains phosphates and potash to supply phosphorus and potassium.
“Natural” fertilizer supplies nitrogen phosphorus and potassium in the form of compounds found in manure and compost although these are not as readily absorbed as the components of scientifically blended synthetic fertilizer. The latter commonly results in faster growth and higher yield. To improve the efficacy of “natural” or “organic” fertilizer, minerals, ground sea shells, bloodmeal, bone meal, feather meal, hides, hoofs, and horns may be added. While sewage sludge does contain the nutrients plants require, it is usually not acceptable as an “organic” fertilizer due to possible contamination by environmentally persistent residues from various industrial products.
Unfortunately, in a popular tale – chemicals are “evil” and are found in synthetic substances. That, of course, is irrational. Everything in the world, including compost and manure is composed of chemicals. Indeed, there are far, far more chemicals in natural fertilizers than in synthetics. Yes, the hydroxylamine, nitrates, ammonium phosphates, potassium carbonates, peptides, fatty acids and hundreds of other compounds are “natural,” but that in terms of efficacy or toxicity is neither here nor there. The properties of chemicals do not depend on their source.
Natural fertilizers do have some benefits. They can contain more micro-nutrients than synthetics and produce less pollution due to run-off. However, the lower yield associated with organic farming means more land must be devoted to agriculture to feed the same number of mouths. Deforestation isn’t all that good for the environment. In Sri Lanka, around six times more manure is needed to provide the same amount of nitrogen as was available from synthetic fertilizer in the past. Organic fertilizer may sometimes contain concerning amounts of bacteria present.
Ignoring the many economists and scientists who urged the Sri Lankan government not to follow through with a ban on synthetic fertilizer, Rajapaksa instead sided with advocates like Vandana Shiva, an Indian environmental activist who does not have a background in agriculture.
Some health professionals have also called for the synthetic ban because they believe that agrochemicals are causing the chronic kidney disease (CKD) epidemic in Sri Lanka’s North Central Province. The World Health Organization (WHO) launched an investigation that found traces of cadmium and arsenic in the population and environment. Although the levels were not found to be unsafe, continuous exposure could possibly be causing the damage. Cadmium is sometimes used in fertilizer, and some pesticides use arsenic (though these pesticides are banned in Sri Lanka). Despite all this, WHO has yet to release the full study, and not enough research has been conducted to confirm this possible connection. Diabetes and hypertension are usually the primary causes of CKD, and farmers in other parts of the country, who also used synthetic fertilizer, aren’t affected by the illness.
Fast forward a few months and the government backtracked on the synthetic fertilizer ban because yields dropped significantly. Rice production fell 20%, and the loss in tea production is estimated to be worth almost as much as was gained by scrapping the original synthetic fertilizer subsidies. Sri Lanka had to start importing food and compensating farmers. Along with many other factors such as the pandemic and poor economic decision-making, this all contributed to the wreckage of the country’s economy.
Rajapaksa stepped down July 13th after protesters forced their way into the presidential palace. What we have here is a cautionary tale that you can’t make a transition to all-organic overnight, nor can you scale it up across an entire country. It is not like deciding that you will go “organic” in your back yard vegetable garden.
Haleh Cohn just finished her first year at McGill University and is interested in the health sciences.