Petrochemical fertilisers include ammonium nitrate, urea, nitric acid and anhydrous ammonia. They’re obtained using natural gas as a source of fuel and hydrogen for chemical reaction to take place; end result is fertiliser. In contrast, chemical fertilisers are convenient and economical source of nitrogen for plants however their use and production is quite expensive.
Gardeners are aware of both naturally derived and synthetic products! Petrochemical fertiliser is an alternate name for synthetic products as they’re produced with large consumption of fossil fuels and petroleum. Petrochemical fertilisers have both positive and negative effects on environment including plants but these are often misunderstood by end consumers.
Fluctuating cost of natural gas and production of petrochemical fertilisers are correlated to each other. Whereas average cost of chemical fertilisers is typically compared to organic products. When considering chemical fertiliser production on industrial scale, process is simple and mostly comprised of chemical reactions. Petrochemical industry usually concentrates production in areas known for abundance of natural gas. Gas in these areas is usually cheap but whenever cost rises, companies use alternate hydrocarbon fuels as energy source.
Petrochemical fertilisers are a primary source of nitrogen when compared with organic produce. Nitrogen content varies randomly in organic fertilisers but not in chemical compounds where it’s high and easily quantifiable. This nitrogen in chemical fertilisers is readily available for plants as compared to organic fertilisers till it breaks down eventually.
Pollutants & Greenhouse Gases
Production of petrochemical fertilisers is an important pollutant source. Carbon dioxide and many other greenhouse gases are a derivative of fertiliser manufacturing. When released in open air, these gases have a negative impact on climate. Production of fertilisers creates toxic chemicals in large volume that are also released in air and water around the facilities causing serious landfill and other environmental damage.
Nitrogen content present in fertilisers might compose water soluble or insoluble compounds. Water soluble nitrogen is readily available to plants and that’s the biggest advantage of synthetic fertilisers. Its abundant use in growth of plants is a fine example and results usually come out positive. Water insoluble nitrogen is also known as “slow release” fertiliser that must be broken down into the soil first.
A few fertilisers like ammonium nitrate and anhydrous ammonia are highly explosive, thus raising a threat against safety, both during production and in their final shape. Finest example of this is the 2013 blast incident at a fertiliser plant in West Texas, killing 15 while damaging 350 homes. Explosion was fuelled by ammonium nitrate while such fertilisers are potentially exploited by terrorist and criminals thus a major security risk! Developing petrochemical industries in Saudi Arabia have harnessed fool-proof safety measures to avoid such a disaster.
Health Impact on Soil
As nutrients from fertilisers are absorbed directly by plants, there’s little benefit to soil that eventually becomes more of a growing medium instead of fertility. This is perhaps the biggest gap in organic gardening, a method to cultivate fertile soil that’s healthy and productive for plant growth. Since healthy soil resist potential plant diseases against pests, that’s a major drawback of relying solely on petrochemical fertilisers. Besides, they contain more salts that are toxic to plant life if not seeped out with heavy irrigation.
It’s clear that petrochemical fertilisers have both positive and negative aspects depending on how they’re used and in what quantity.