Why in the News?

One hundred million tonnes of nitrogen are extracted from the atmosphere and transformed into fertilizer through the Haber-Bosch process, adding 165 million tonnes of reactive nitrogen to the soil.

What is the Nitrogen molecule and how is it availed in Nature?

• The nitrogen molecule (N2) consists of two nitrogen atoms joined by a triple bond, sharing three pairs of electrons. This triple bond makes the molecule extremely stable and nearly inert, requiring a significant amount of energy (946 kJ/mol) to break.
  • When the triple bond is broken, nitrogen atoms can form reactive nitrogen compounds like ammonia (NH3), ammonium (NH4+), or nitrates (NO3–). 
  • These compounds are essential for plant growth as they help synthesize enzymes, proteins, and amino acids.

• Lightning generates enough energy to break the N2 triple bond, producing nitrogen oxides (NO and NO2) that can combine with water vapor to form nitric and nitrous acids. These acids add reactive nitrogen to the soil through rainfall.
• Certain bacteria, such as Azotobacter and Rhizobia, fix atmospheric nitrogen through biological processes.
  • Rhizobia forms symbiotic relationships with legumes, while Azolla, an aquatic fern, also fixes nitrogen via its symbiotic cyanobacterium.

What is the Haber-Bosch process?

• The Haber-Bosch process synthesizes ammonia by reacting nitrogen (N2) with hydrogen (H2) under high pressure (200 atm) and moderate temperature (200°C), using a catalyst (typically iron oxides).
• The process was developed by Fritz Haber, who found that high pressure and a suitable catalyst were key to converting nitrogen to ammonia efficiently. The setup was scaled up by Carl Bosch, leading to the first ammonia production plant in 1913.

What are the downsides of fertilizers?

• Environmental Impact: While synthetic nitrogen fertilizers have significantly increased food production, they have also led to negative environmental effects:
  • Over-fertilization: Excess nitrogen application results in reactive nitrogen being released into the atmosphere, contributing to acid rain and soil degradation.
  • Water Pollution: Nitrogen runoff from agricultural fields enters freshwater and coastal ecosystems, leading to eutrophication, which causes oxygen depletion and harms aquatic life.
  • Human Health Concerns: High nitrogen levels in drinking water can pose health risks.
• Socio-Economic Challenges: Despite increased food production, issues such as starvation, malnutrition, and unequal food distribution persist, highlighting that technological solutions like fertilisers are insufficient; social and political action is also needed.

Way forward: 

• Promote Sustainable Fertilizer Use: Encourage the adoption of precision agriculture techniques, such as soil testing and site-specific nutrient management, to optimize fertilizer application. This approach minimizes over-fertilization, reduces nitrogen runoff, and mitigates environmental damage.
• Strengthen Policy and Regulatory Frameworks: Governments should implement and enforce policies to regulate nitrogen fertilizer use, ensuring that environmental safety standards are met.

Get an IAS/IPS ranker as your 1: 1 personal mentor for UPSC 2024

Attend Now