Fertilizer
Overview
Fertilizer (비료, 肥料) is a material applied to soil or plants to supply inorganic nutrients, including nitrogen (N), phosphorus (P), and potassium (K), needed for crop growth. In the early 20th century, the Haber-Bosch process enabled industrial synthesis by fixing atmospheric nitrogen into ammonia, making fertilizer core infrastructure supporting global population growth. At the same time, as environmental problems such as water pollution from over-fertilization, greenhouse gas emissions, and soil acidification have grown, industry and policy are being reorganized toward managing both 'productivity' and 'sustainability.'
Main Content
Definition and Classification
Fertilizers are broadly divided into inorganic fertilizers (chemical fertilizers) and organic fertilizers. Inorganic fertilizers are further divided into nitrogenous (urea, ammonium sulfate, ammonium nitrate, raw materials for compound fertilizers), phosphatic (superphosphate, fused phosphate, ammonium phosphate), and potassic (potassium chloride, potassium sulfate). Organic fertilizers use organic-derived resources such as compost, manure, green manure, fish meal, and bone meal, and are highly effective at improving soil physical properties and promoting microbial activity.
Depending on the blending method, they are also classified as single fertilizers and compound fertilizers (NPK blends); depending on dissolution rate, as quick-acting fertilizers and slow-release and coated fertilizers (CRF), slow-release and controlled-release fertilizers, and liquid fertilizers and fertigation fertilizers applied with irrigation after dissolving in water. Recently, foliar application products that stabilize trace elements in chelated form and crop-specific customized prescription fertilizers have been spreading.
Plant Nutrients and the Law of the Minimum
Elements required in large amounts by plants are nitrogen, phosphorus, and potassium (primary macronutrients) and calcium, magnesium, and sulfur (secondary macronutrients), while iron, manganese, zinc, copper, boron, molybdenum, and chlorine are classified as micronutrients. Nitrogen is a component of proteins and chlorophyll and determines growth amount; phosphorus is involved in energy metabolism (ATP) and root development; potassium is involved in water regulation, disease resistance, and quality. Liebig's 'law of the minimum' is the principle that the most deficient element limits yield, and it is the theoretical basis for balanced fertilization.
History
In 1840, Justus von Liebig presented the mineral theory, and in 1842 John Lawes patented the manufacture of superphosphate, launching the chemical fertilizer industry. The decisive turning point was the success of Fritz Haber and Carl Bosch in directly synthesizing ammonia (the Haber-Bosch process) in 1913. The 'Green Revolution' of the 1950s-60s combined improved varieties with chemical fertilizers and irrigation, rapidly increasing cereal production in developing countries. Korea laid the foundation for staple grain self-sufficiency through fertilizer production increase policies and fertilizer plant construction in the 1960s; since the 1990s, chemical fertilizer use per unit area has been steadily declining.
Production and Industrial Structure
The starting point for nitrogen fertilizer is ammonia (NH3) synthesis, which is then processed into urea, ammonium nitrate, nitric acid, and other products. The Haber-Bosch process is a representative energy-intensive process, accounting for about 1-2% of global energy consumption and a significant portion of industrial carbon dioxide emissions. Phosphate depends on phosphate rock concentrated in countries such as Morocco and China, while potash depends on mines in a small number of countries such as Canada, Russia, and Belarus, creating structurally large supply chain risks. Korea imports most raw materials and is highly exposed to finished product and raw material price fluctuations; the 'urea solution crisis' triggered by China's urea export controls in 2021 is a case showing supply chain vulnerability, including industrial urea.
Environmental Impact and Management
When nitrogen and phosphorus run off into rivers and lakes, they cause eutrophication and algal blooms, and nitrous oxide (N2O) generated during denitrification of nitrogen fertilizers has a global warming potential hundreds of times that of carbon dioxide. Ammonia volatilization acts as a precursor to fine particulate matter (PM2.5), and over-fertilization leads to soil acidification, salt accumulation, and groundwater nitrate contamination. Internationally, the '4R principles' (right source, right rate, right time, right place) and prescription fertilization based on soil testing are spreading as standardized management measures.
Recent Trends
In 2022, the Russia-Ukraine war and surge in natural gas prices caused large-scale reductions in ammonia production in Europe, and fertilizer prices hit record highs; in 2024-2025, prices have shown relative stability due to supply normalization and changes in China's export policy. However, the uneven distribution of raw materials and energy price volatility remain structural risk factors.
On the industrial side, renewable-energy-based 'green ammonia' and low-carbon nitrogen fertilizers are attracting attention. Along with discussions that carbon regulations such as the EU's Carbon Border Adjustment Mechanism (CBAM) may apply to fertilizer trade, investment in technologies to reduce the carbon footprint of production processes is increasing. In agricultural settings, precision agriculture and variable-rate application (VRT) combining satellite and drone remote sensing (NDVI) with soil sensors are spreading, expanding cases that maintain yields while reducing fertilizer inputs. Biofertilizers using microbial agents and nitrogen-fixing strains, and circular phosphorus resource recovery that recovers phosphorus from sewage sludge and livestock manure, are also entering the commercialization stage.
In Korea, diversification of fertilizer raw material import sources, expansion of stockpiles, and wider distribution of slow-release and coated fertilizers have emerged as policy tasks, and reduction technologies that simultaneously reduce greenhouse gas and ammonia emissions through shallow irrigation and intermittent drainage in rice paddies and optimization of fertilization prescriptions are being distributed at the farm level. Certification of climate-change-responsive 'low-carbon fertilizers' and linkage with carbon reduction performance trading are also being discussed on a pilot basis.
Related Topics
- [[하버-보쉬법]] (Haber-Bosch process)
- [[질소고정]] (Nitrogen fixation)
- [[정밀농업]] (Precision agriculture)
- [[녹색혁명]] (Green Revolution)
- [[토양오염]] (Soil contamination)