Smart Fertilizers for Sustainable Agriculture: A Review

Agricultural systems currently occupy nearly 40–50% of the Earth’s terrestrial surface and are central to global food security, yet they face increasing pressure due to rapid population growth and environmental degradation. However, increasing population pressure and the need for higher food production have intensified the demand for efficient nutrient management strategies. Conventional fertilizers, although widely used, suffer from low nutrient use efficiency due to substantial losses through leaching, volatilization, runoff, and fixation, leading to environmental degradation and economic inefficiencies. These losses contribute to groundwater contamination, eutrophication, greenhouse gas emissions, and deterioration of soil health. In response to these challenges, smart fertilizers have emerged as an innovative approach to enhance nutrient use efficiency and promote sustainable agriculture. These include nano fertilizers and slow or controlled release fertilizers, which are designed to synchronize nutrient availability with plant demand. Nano fertilizers, owing to their small particle size, high surface area, and enhanced reactivity, facilitate improved nutrient absorption and targeted delivery while minimizing environmental losses. Similarly, slow and controlled release fertilizers regulate nutrient release through coating materials and matrix systems, ensuring a steady nutrient supply over time and reducing the frequency of fertilizer application. The adoption of these advanced fertilizer technologies offers multiple agronomic, environmental, and economic benefits, including improved crop productivity, reduced nutrient losses, enhanced soil fertility, and lower environmental risks. Furthermore, they play a crucial role in achieving sustainable intensification of agriculture by optimizing resource use and minimizing ecological footprints. Overall, smart fertilizers represent a promising solution for addressing the limitations of conventional fertilization practices and advancing sustainable agricultural systems. Continued research and technological development are essential to improve their efficiency, scalability, and field-level applicability under diverse agro-ecological conditions.