By George George Idowu
Indian researchers have made a significant breakthrough in understanding rice’s natural variations in Nitrogen Use Efficiency (NUE). This discovery has the potential to revolutionise sustainable agricultural practices in the country.
The study, published in the Journal of Plant Growth Regulation, reveals that certain rice varieties possess remarkably high NUE, offering a pathway to more efficient and environmentally friendly farming.
The research, conducted by a team from Indraprastha University, focused on evaluating NUE in various rice varieties, identifying important traits and genes associated with this critical efficiency.
NUE measures how effectively plants utilise nitrogen from fertilisers, specifically urea, the predominant nitrogen fertiliser used in India.
High NUE results in more grain yield per unit of nitrogen fertilizer, making it a vital factor in agricultural sustainability.
The study highlights several rice varieties with exceptional NUE.
While Khira and CR Dhan 301 were identified as high NUE crops, they were also found to be long-duration varieties. On the other hand, the Dhala Heera variety demonstrated high NUE and had shorter growth duration, offering a significant advantage for farmers who need to optimise their crop cycles.
The research involved a comprehensive analysis of 46 phenotypic and physiological parameters across various rice varieties. The findings revealed a five-fold variation in NUE among a dozen rice varieties screened from over a thousand Indian varieties. This extensive study spanned over a decade and was conducted in three separate phases, using different sets of 34 released rice varieties under greenhouse conditions. The varieties identified as high NUE in the greenhouse were later confirmed in field trials, reinforcing the reliability of the findings.
“We identified 19 parameters strongly associated with NUE, including eight newly discovered ones, pending confirmation in field trials,” explained Ashu Tyagi, a researcher who conducted this study as part of her doctoral thesis.
The success of these trials suggests that large-scale screening of all Indian rice varieties could be conducted to identify more cultivars with high NUE. Such cultivars could then be tailored to different agroclimatic conditions and market demands, offering a more sustainable approach to rice cultivation in India.
The importance of improving NUE in rice extends beyond mere agricultural productivity. Poor NUE has significant environmental repercussions. The inefficient use of nitrogen fertilizers leads to the wastage of nitrogen worth approximately Rs 1 lakh crore annually in India and over $170 billion globally.
Moreover, poor NUE contributes to environmental degradation, particularly through greenhouse gas emissions and water pollution.
Nitrogen fertilizers are a major source of nitrous oxide, a potent greenhouse gas that contributes to climate change. Additionally,
nitrogen runoff into water bodies causes eutrophication, leading to oxygen-depleted “dead zones” that severely impact aquatic ecosystems. Enhancing NUE in rice cultivation can mitigate these environmental issues, promoting more sustainable and eco-friendly agricultural practices.
The socio-economic benefits of improved NUE are equally profound. In India, where agriculture is a cornerstone of the economy and a primary source of livelihood for millions, improving NUE can significantly boost productivity and profitability for farmers. By reducing the need for excessive fertilizer application, farmers can lower their input costs while minimizing their environmental impact. This could lead to a more sustainable agricultural economy, ultimately improving living standards in farming communities.
India’s commitment to the Kunming-Montreal Global Biodiversity Framework (2022), which mandates countries to halve nutrient waste from all sources by 2030, underscores the urgency of improving NUE. The findings from this study align with these global efforts, providing a scientific basis for enhancing rice cultivation practices in India.
The next steps involve confirming the newly identified parameters associated with NUE in field trials and conducting large-scale screenings of rice varieties across different regions of India. Such efforts could lead to the development of new high-NUE rice cultivars that are better suited to various agroclimatic conditions, further advancing sustainable agriculture in the country.
In conclusion, the discovery of natural variations in rice NUE and associated traits by Indian scientists marks a significant milestone in the pursuit of sustainable agriculture. By leveraging these findings, India can enhance its agricultural productivity, reduce environmental impact, and improve the livelihoods of millions of farmers, contributing to a more sustainable and prosperous future.
