Excess nitrogen threatens agriculture and the environment

The growing dependence on nitrogen fertilizers to feed an expanding global population now poses a major challenge. While these fertilizers have helped sustain agricultural yields, their excessive use degrades soils, reduces their fertility, and threatens long-term productivity. The immoderate application of nitrogen acidifies the land, depletes its nutrient richness, and releases toxic elements such as aluminum, which are harmful to plant roots. Crops, initially stimulated by abundant input, eventually suffer from an imbalance: excessive vegetative growth at the expense of grain formation, which weakens stems and increases the risks of disease or plant collapse.

The environmental consequences are equally concerning. Excess nitrogen transforms into harmful compounds such as nitrous oxide, a greenhouse gas far more potent than carbon dioxide. It also contributes to air pollution through ammonia, which degrades atmospheric quality and worsens respiratory problems. In water, nitrates from fertilizers seep into groundwater, sometimes making the water unfit for consumption and causing algal blooms in waterways, suffocating aquatic life. Nitrogen oxides, meanwhile, contribute to the formation of acid rain and ground-level ozone, which are harmful to ecosystems and infrastructure.

In response to this situation, solutions are emerging to improve nitrogen efficiency while preserving soils. Precision agriculture, using tools like sensors or drones, allows inputs to be adjusted according to the actual needs of crops, thereby limiting waste. Alternative practices are also gaining ground: no-till farming, which preserves soil structure and reduces emissions, or cover crops such as clover or alfalfa, which can fix atmospheric nitrogen or trap residual nitrogen in the soil after harvests. Organic amendments, such as biochar or compost, improve nutrient retention and stimulate microbial activity, creating a virtuous cycle for soil fertility.

Technological innovations play a key role. Slow-release fertilizers or nano-fertilizers better target plant needs, reducing losses and the required doses. Public policies, such as targeted subsidies or taxes on excess nitrogen, encourage more responsible use. In Europe, countries like Denmark and the Netherlands have implemented mandatory nutrient accounting systems, while in China, the “two zeros” policy has significantly reduced fertilizer use without sacrificing production. In India, soil health cards help farmers adjust their inputs based on soil analysis.

However, the adoption of these practices faces obstacles, particularly in small farms. Lack of financial resources, limited access to agronomic advice, and local traditions hinder change. To address this, it is essential to strengthen agricultural advisory services, making them more accessible and focused on farmers’ needs. Practical demonstrations, visual training, and digital platforms can facilitate knowledge sharing. Collaboration between public, private, and associative sectors is also necessary to develop fertilizers adapted to local contexts and promote a circular management of nutrients, where organic waste is recycled into useful resources.

The challenge is significant: reconciling food security and environmental preservation requires smarter nitrogen management, combining innovation, training, and cooperation at all levels.

Source Mentions

Cited Publication

DOI: https://doi.org/10.1007/s11368-026-04423-5

Title: Nitrogen fertilizer use in agroecosystems: current practices, policies and recommendations for efficiency improvement

Journal: Journal of Soils and Sediments

Publisher: Springer Science and Business Media LLC

Authors: Md Hafiz All Hosen; Shilpi Das; Georgette Leah Burns; Apurbo Kumar Chaki; Mrinmoy Guha Neogi; Md. Wakilur Rahman; Michael B. Farrar; Mehran Rezaei Rashti; Mahbubur Rahman Khan; Brittany Elliott; Shahla Hosseini Bai