Imphal, Apr 25: Enhancing nutrient use efficiency (NUE) through organic inputs is emerging as a key strategy for sustainable agriculture, amid rising fertiliser costs and growing environmental concerns, according to agricultural expert A.S. Mailappa of the Central Agricultural University, Imphal.
NUE—defined as the crop yield obtained per unit of nutrient applied—remains relatively low across major nutrients. Nitrogen efficiency ranges between 20–40%, while phosphorus efficiency can be as low as 10–30%, indicating that a significant proportion of applied fertilizers is lost to the environment through leaching, volatilization, and erosion.
“These losses not only increase the cost of cultivation but also contribute to environmental problems such as water pollution and greenhouse gas emissions,” Mailappa noted, highlighting the urgent need for more efficient nutrient management practices.
Organic manures, including farmyard manure, compost, and poultry waste, are being promoted as effective alternatives or supplements to chemical fertilizers. These inputs release nutrients gradually, improving nutrient uptake while reducing losses. In addition, biofertilizers containing beneficial microorganisms help fix atmospheric nitrogen, solubilize phosphorus, and enhance root development.
Experts emphasise that organic inputs also play a crucial role in improving soil health by increasing soil organic carbon, enhancing microbial activity, and improving soil structure and water retention capacity.
The adoption of the 4R Stewardship approach—applying the right source of nutrients at the right rate, right time, and right place—has been identified as essential for improving NUE. According to Mailappa, practices such as soil testing, split nutrient application, and precision farming technologies can significantly enhance nutrient efficiency.
“Synchronising nutrient supply with crop demand is critical, particularly for nitrogen management,” he said, adding that tools such as leaf colour charts, chlorophyll meters, and sensor-based technologies are increasingly being used to guide fertilizer application.
Studies have shown that the application of organic manures can significantly improve crop yields and quality. Yield increases have been recorded in crops such as okra, tomato, maize, and soybean, alongside improvements in nutritional quality, including higher vitamin content and antioxidant activity.
Organic inputs also contribute to climate-resilient agriculture by improving crop tolerance to abiotic stresses such as drought, salinity, extreme temperatures, and heavy metal contamination. Improved soil organic matter and water-holding capacity enable crops to better withstand adverse conditions.
In addition, organic manures help enhance soil fertility by increasing microbial biomass and promoting beneficial soil organisms that aid nutrient cycling.
While organic inputs offer multiple benefits, experts stress the importance of their judicious use based on crop type, soil conditions, and local climate. Integrating organic manures with chemical fertilizers is seen as a balanced approach to achieving both high productivity and sustainability.
“Increasing awareness among farmers about the benefits of organic nutrient management is essential for advancing smart farming and ensuring long-term agricultural sustainability,” Mailappa added.
