News Excerpt:

A recent study has uncovered a wide variation in nitrogen-use efficiency (NUE) among popular rice varieties in India.

What is Nitrogen-Use Efficiency?

• Nitrogen-use efficiency (NUE) refers to the amount of crop yield produced relative to the nitrogen available to the crop, whether from natural or artificial sources. 
• High NUE means that a crop can produce more yield with less nitrogen, making it more efficient and environmentally friendly. 
• Improving NUE is crucial for reducing fertilizer waste and minimizing the environmental impact of agricultural practices.

Key findings of the study:

• The study, conducted by biotechnologists in Guru Gobind Singh Indraprastha University (GGU) in New Delhi, revealed that the NUE of the best-performing rice varieties was up to five times higher than that of the least efficient ones.
• This variation highlights the potential for selecting and breeding rice varieties that are more nitrogen-efficient.
• However, it was noted that a high NUE does not always correspond to the highest yields, which are generally preferred by farmers in India.
• Historically, the focus of Indian agriculture has been on maximizing yield, particularly during the Green Revolution.
  • This emphasis led to increased use of synthetic fertilizers, resulting in significant waste and pollution.

• • Currently Cereal consumes two-third of Urea in India which is led by rice cultivation.

• Although India has tens of thousands of rice varieties, only a few are extensively studied and used in agricultural research. 
• The study suggests that a broader approach is necessary to identify and develop new crops that combine high NUE with desirable yields.

Implications for Agriculture and the Environment

• This discovery could pave the way for developing new rice strains that require less nitrogen while maintaining high yields, potentially reducing the country’s reliance on imported fertilizers and decreasing nitrogen-related environmental pollution.
• Improving NUE is not only beneficial for crop production but also crucial for environmental sustainability. 
• Fertilizers are a major source of nitrous oxide (N2O), a potent greenhouse gas that contributes to climate change. 
• India, the world’s second-largest emitter of N2O, was responsible for nearly 11% of global man-made emissions in 2020, primarily due to fertilizer use. 
• The research also identified 19 key parameters associated with NUE, including eight that were discovered for the first time.
• These findings, confirmed through both greenhouse and field trials, provide a reliable methodology for assessing NUE in rice.

Way Forward: 

• The study recommends large-scale screening of all Indian rice varieties to identify more NUE cultivars that are suited to different agro climatic conditions and markets.
• In addition to improving crop varieties, the study suggests that enhancements in fertilizer formulations, legume-based crop rotations, and crop management practices could also contribute to better NUE. 
• However, the most significant gains are likely to come from advancements in biotechnology, which can be used to develop rice strains that are both nitrogen-efficient and high-yielding.