nitrogen fertilizers

What is nitrogen fertilizer?

Nitrogen (N2) is a chemical element that constitutes the majority of the earth’s atmosphere, which makes it an essential element for the growth of plants and vegetation. Assimilated by plants in the form of nitrates (NO3), it can nevertheless be insufficient for their development. 

For better yields, an additional dose of nitrogen to the one already present in the soil is necessary. 

This nitrogen addition can be achieved in two different ways : 

  • via an organic additive (manure, dung, etc.)
  • via a mineral additive (fertilizers which contain only one major nutrient such as nitrogen, potassium sulfate or phosphate)

Nitrogen fertilizer refers to a mineral input into the soil, made from nitrogen already present in the atmosphere. 

Nitrogen fertilizers are mainly composed of ammonia (NH3), obtained by combining the nitrogen contained in the air and hydrogen (H2).

plants growth

Its role in plants growth : 

Nitrogen constitutes a major part of the plants’ DNA. In fact, this chemical element is contained in all proteins, nucleic acids as well as the various amino acids composing the plants. 

If these plants experience color changes or a sudden slowdown in their growth, it may be because they have a nitrogen deficiency, as it is actively involved in the development of plants and vegetation, particularly on their external parts. Thus, it is nitrogen that gives them their greenness and foliage (e.g. : chlorophyll).

Below is a list of the main existing nitrogen fertilizers : 

  • Ammonium nitrate base
  • Ammonium nitrate + urea
  • Ammonium nitrate + urea + ammonium sulfate
  • Urea
  • Anhydrous ammonia
  • Ammonium sulphate
  • Calcium cyanamide
  • Chilean soda nitrate
  • Nitrate of lime
  • Calcium nitrate

The risks associated with the use of nitrogen fertilizer

The use of nitrogen fertilizers inevitably involves certain risks and dangers. These may include risks of exposure to toxic and chemical substances or explosive substances. They can also be considered as threats to biodiversity and ecology. 

Chemical risks

Ammonium nitrate, which is the main component of nitrogen fertilizer, can become dangerous if you are exposed to it in high concentration (accidents in the professional agricultural sector are still relatively rare). The repercussions that can be observed following a high exposure to these chemicals can include eye, mucous and respiratory tract irritation, coughing and breathing difficulties. Tearing, pain, vision problems and other corneal irritation may also occur.

Explosion and fire risks of fertilizers

This same component, ammonium nitrate, is an “occasional explosive”, even if its concentration must be very high to create an explosion. This may occur if ammonium nitrate and other ammonitrates are exposed to a high energy input (explosive projectiles or flames).

If a fire or an explosion happens, the nitrogen fertilizer will release toxic gases (carbon monoxide - CO, carbon dioxide - CO2, ammonia - NH3 or nitrogen oxide - NxOy) as well as some volatile organic compounds while decomposing.

Biological risks

In addition to the chemical and explosion risks, nitrogen fertilizers represent certain threats to the environment. Nitrogen residues from nitrogen fertilizers are believed to be, partially, responsible for the proliferation of harmful seaweeds through the process of eutrophication causing the surface waters to deteriorate. The decreasing fertility of the soil is also one of the collateral damages of using nitrogen fertilizers, due to the acidification of the soil. Their use also contributes to global warming caused by high emissions of nitrous oxide (N2O), thus increasing the greenhouse effect. It also takes part in the hole in the ozone layer.

Nitrogen fertilizers encourages the use of pesticides 

Too much consumption of the synthetic fertilizer (nitrogen fertilizer), can also have consequences on agriculture itself. 

Indeed, its use in too large quantities leads farmers to use high doses of pesticides. Basically, the more nitrogen fertilizer is used in crops, the more nitrate and amino acids will be stored in the leaves and tissues of the plants. But the problem is that insects are very fond of these substances and will therefore end up multiplying. Plus, knowing that these insects can cause serious damages to crops, farmers have no choice but to use enormous quantities of pesticides to neutralize these pests.


How to protect yourself when using fertilizers?

In the agricultural sector it is necessary to wear adequate protection to use chemical products such as nitrogen fertilizer and other pesticides etc. The phytosanitary treatment mask is therefore the most effective solution. 

Half masks with safety glasses or full face masks designed to provide optimal respiratory and eye protection are available. These masks must be used with A2-P3 respiratory protection cartridges (based on activated carbon). Wearing a microporous workwear or a chemical workwear is also recommended.

half mask

Standards and regulations on synthetic fertilizers

Like the majority of chemical substances, nitrogen fertilizer is subject to strict standards and regulations. The main standard to respect when producing or using synthetic fertilizers is the NFU 42001 of December 1981 for organo-mineral fertilizers. According to this standard, certain information of marking must imperatively be present on the product (see amendment A10: 2009). 

Among these elements of markings to appear: 

  • Title of the fertilizer
  • Type of fertilizer
  • The person responsible for putting the product on the market
  • Net mass supplied
  • Guaranteed contents in fertilizing elements