Biotechnologists detect difference in use of nitrogen by rice varieties
Context
Biotechnologists at Guru Gobind Singh Indraprastha University (GGU), New Delhi, have discovered significant variations in the nitrogen-use efficiency (NUE) among popular rice varieties in India.
- This research holds potential for developing new rice varieties that are both high-yielding and require less nitrogen, thereby reducing fertilizer costs and nitrogen-linked environmental pollution.
Relevance:
GS-03 (Biotechnology)
Key Findings:
- There is a wide variation in NUE among different rice varieties in India, with some varieties demonstrating up to five times more efficiency than others.
- Nitrogen-use efficiency refers to the yield of a crop relative to the nitrogen (natural and artificial) available to it.
- Despite high NUE, these varieties do not necessarily produce the highest yields, leading farmers to often prefer high-yielding varieties that may not be as nitrogen-efficient.
- Current agricultural practices focus primarily on increasing yield, leading to excessive use of synthetic fertilizers, wastage, and environmental pollution.
Significance:
- Economic Impact: Poor NUE results in significant economic losses, with nitrogen fertilizers worth ₹1 trillion wasted annually in India and over $170 billion globally.
- Environmental Concerns: N-fertilizers are major contributors to nitrous oxide and ammonia pollution, as well as nitrate and ammonium contamination in water, affecting human health, biodiversity, and contributing to climate change.
- Agricultural Sustainability: Developing rice varieties with better NUE can reduce dependency on imported fertilizers, decrease environmental pollution, and promote more sustainable agricultural practices.
Key highlights about nitrogen:
- Essential Nutrient: Nitrogen is a crucial nutrient for all living organisms, integral to molecules like proteins, nucleic acids (DNA and RNA), and vitamins.
- Atmospheric Abundance: Nitrogen gas (N2) constitutes 78% of Earth’s atmosphere, yet it is largely inaccessible in this form to most organisms.
- Scarcity in Ecosystems: Despite its abundance, nitrogen is often a limiting resource in ecosystems because it must be converted into a usable form.
- Nitrogen Fixation: The process of converting nitrogen gas (N2) into ammonia (NH3), making it biologically available, is known as nitrogen fixation, performed by certain microorganisms.
- Major Nitrogen Transformations: The key processes include nitrogen fixation (N2 to NH3), nitrification (NH3 to nitrite and nitrate), and denitrification (nitrate back to nitrogen gases).
- Types of Nitrogen-Fixing Organisms: These organisms can be free-living or symbiotic, aerobic or anaerobic, and phototrophic or chemotrophic, all utilizing the enzyme nitrogenase for nitrogen fixation.
- Biological Importance: Nitrogen is found in vital compounds such as alkaloids and urea, underscoring its significance across various biological systems.
Way Forward
- A broader approach in agricultural research is needed, focusing not just on yield but also on NUE to identify and promote rice varieties that balance both.
- Improvements in NUE can be achieved through better fertilizer formulations, legume-based crop rotations, and crop management practices.
- Enhanced focus on biotechnological advancements is necessary to develop rice varieties that are both high-yielding and nitrogen-efficient, ensuring sustainable agricultural growth in India.
