Relative Assessment of Fertilizer Application Techniques for Enhancing Nutrient Use Efficiency, Crop Productivity, Soil Health and Environmental Sustainability: A Review

Enhancing fertilizer application strategies is a critical lever for addressing the multidimensional challenges confronting modern agriculture, including food security, resource sustainability, and environmental health. While the evolution from conventional broadcasting to advanced placement techniques-such as banding, deep placement, fertigation, and foliar application, led to measurable gains in Nutrient Use Efficiency (NUE) and yield, substantial research gaps and contradictions persist, particularly regarding their long-term, context-specific impacts. This review synthesizes comparative studies and quantitative meta-analyses, revealing that precision methods can increase crop yields by 10% – 40% and reduce nitrogen losses by up to 25% - 40% compared to broadcasting, but their performance varies significantly across crops, soils, and socio-economic settings. Key concerns remain, especially in India, regarding persistent imbalance in fertilizer use (notably excess nitrogen relative to phosphorus and potassium), declining soil organic matter, depletion of micronutrients, and insufficient adoption of precision technologies by smallholders. Globally, indiscriminate fertilizer application continues to drive soil degradation, greenhouse gas emissions, and water pollution, while policies often lag behind scientific advancements. Contradictions in the literature highlight that while certain placement methods outperform others in specific agro-ecological conditions, their scalability is limited by infrastructure, cost, and knowledge barriers. Future perspectives emphasize the urgency of developing adaptive nutrient management frameworks tailored to local realities, supported by soil testing infrastructure, policy incentives, digital agriculture tools, and strong farmer education. For policymakers, integrating the 4R framework-right source, rate, time, and place-into national resource strategies, reorienting subsidies toward balanced nutrients, and promoting the inclusion of small and marginal farmers in technological transitions are imperative. Coordinated global and national efforts are needed to foster equitable access to efficient fertilizer technologies, build resilience against climate variability, and ensure the sustainability of food systems. Only a systems-based, inclusive approach will enable sustainable intensification and secure agricultural productivity for present and future generations.