Increasing nutrient use efficiency through organic sources: its strategies and future perspectives

Latest reports suggest around 65% of the population depends on agriculture and allied sectors, particularly in rural areas and approximately 46.1% of the total workforce is directly engaged in agriculture and allied activities in India. The ‘Agriculture and Allied Activities’ sector has long been the backbone of the Indian economy, playing a vital role in national income and employment. Whereas, the agricultural sector and allied activities constitute only about 17-18% of India’s Gross Domestic Product (GDP).Present day agriculture relies heavily on chemical fertilizers to increase crop production and assure global food security. As agricultural demand grows globally, the number of countries relying on imports for fertilizers will only rise. India ranks as the largest importer of fertilizers, especially nitrogen and phosphorus products, in the world. The country’s agricultural sector is dominated by smallholder farmers managing fragmented landholdings across diverse agro-climatic zones, who collectively consume approximately 25 to 30 million tonnes of chemical fertilizers annually, making India one of the largest fertilizer consumers in the world.Recently, the National Academy of Agricultural Sciences (NAAS), the apex body of agriculture scientists headed by Director-General, Indian Council of Agriculture Research (ICAR), emphasised on strengthening research for development of smart alternate fertilisers among other measures to become self-sufficient in crop nutrients by 2047.

Expecting that there may be limitation in resources of chemical fertilizers in near future;improving nutrient used efficiency [NUE] is essential to reduce waste, lower costs, and protect the environment.Against this background, organic sources have gained renewed scientific and policy attention as cost-effective, environmentally benign tools for improving NUE. Organic inputs function through multiple, interacting pathways. They supply a slow-release pool of mineralized nutrients that better aligns with crop demand curves, thereby reducing peak losses. They serve as a substrate for soil microbial populations, stimulating enzymatic activity and accelerating the cycling of nutrients from organic to plant-available forms. They improve soil physical properties such as aggregate stability, water infiltration, and moisture retention, indirectly reducing physiological stresses that limit nutrient uptake by roots. Specific microbial groups within biofertilizer products, notably Rhizobium spp., Azotobacter spp., phosphate-solubilizing bacteria, and arbuscular mycorrhizal fungi, directly expand the root-accessible nutrient pool through biological nitrogen fixation,organic acid secretion, and hyphal extension into the soil matrix beyond the nutrient depletion zone surrounding roots.

Table 1. Comparative summary of organic source strategies for NUE improvement: Benefits, limitations, and adoption potential in India

FYM = farmyard manure; SOC = soil organic carbon; BNF = biological nitrogen fixation; PSB = phosphate-solubilizing bacteria; PGPR = plant growth-promoting rhizobacteria; INM = integrated nutrient management; NMSA = National Mission for Sustainable Agriculture; ICAR = Indian Council of Agricultural Research.

Future Perspectives and Policy Implications for Scaling NUE-Improving Organic Strategies

Organic sources cannot fully replace chemical NPK (Nitrogen, Phosphorus, Potash)-yields would collapse. But they can significantly substitute 20-40% of synthetic nutrients and replace 100% of micronutrients, acting as a buffer against import shocks.Organic sources, whether applied individually or within an integrated nutrient management framework, consistently and significantly improve NUE across diverse crop-soil systems, with benefits for crop productivity, soil health, and environmental quality that compound over time. Translating this evidence into widespread practice requires addressing both the technical and institutional dimensions of organic source adoption. On the technical side, the development of nano-organic fertilizers and bio stimulant-enriched composts represents a frontier that could dramatically improve the nutrient density, application efficiency, and precision of organic amendments, making them practical for intensive production systems even where land and water resources are constrained. Application of genomics, metagenomics, and metabolomics to the characterization of soil microbial communities under organic management is revealing the specific microbial guilds and metabolic pathways responsible for NUE improvement, opening the possibility of engineering biofertilizer consortia with precisely targeted nutrient-cycling functions for specific soil types and crop systems.

India’s National Mission for Sustainable Agriculture (NMSA) and the Soil Health Card  (SHC) scheme have created important institutional infrastructure for promoting INM and organic nutrient management, but scaling requires more ambitious investment in organic matter production capacity, including on-farm biogas digesters, village-level composting centers, and vermicompost production units, linked to extension networks that provide farmers with material characterization data and crop-specific application guidelines. Carbon credit mechanisms and environmental payment for ecosystem services from organic agriculture need to be operationalized under India’s carbon market framework to provide smallholder farmers with an economic incentive that closes the short-term cost gap between chemical fertilization and INM. International development agencies and multilateral climate funds represent important additional sources of financing for scaling organic NUE improvement strategies in developing country farming systems, given their dual contribution to food security and climate mitigation objectives aligned with the Sustainable Development Goals.

Authors:

1. Sheetanshu Gupta: Assistant Professor,College of Food Technology, Lamphelpat, Manipur

(sheetanshugupta1983@cau.ac.in)

2. Ng Taibangnganbi Chanu, Assistant Professor, College of Food Technology, Lamphelpat, Manipur(taibangngathem@gmail.com)
3. Jaya Prajapati, Assistant Professor, College of Agriculture, Imphal, Manipur(jaya.prajapati20@gmail.com)
4. NongthombamSurbala Devi, Associate Professor, College of Agriculture, Imphal, Manipur

(sursakti@gmail.com)