The most basic application of industrial ammonia in agriculture is the manufacture of nitrogen fertilizers, which consumes about 80% of the world’s synthetic ammonia. The global nitrogen fertilizer market will be valued at US $143 billion in 2023, and 85% of the raw materials of urea, ammonium nitrate and compound fertilizers are dependent on industrial ammonia, with 0.58 tons of liquid ammonia consumed in the manufacturing of each ton of urea. In China, for example, the output of urea in 2023 will be 56 million tons, which is equivalent to the consumption of industrial ammonia of about 32.5 million tons, accounting for 73% of the country’s total output of synthetic ammonia. According to the United States Department of Agriculture statistics, agricultural yield of corn can be increased by 15%-22% through the use of nitrogen fertilizer, but excessive use will lead to a nitrogen utilization rate of only 35%-40%, and the remaining portion will exist as ammonia volatilization (loss rate of 18%-25%) or nitrate leaching environmental pollution.
In the field of soil improvement, industrial ammonia reduced nitrogen loss through nitrification inhibitor technology. For example, the addition of dicyandiamide (DCD) ammonia solution can reduce the nitrification rate of the soil by 40%-60%, volatilization of ammonia by 30%, and cause the nitrogen utilization rate to increase to 55%-65%. In 2023, 12 million hectares of arable land in Brazil will use this technology, which will result in an average yield increase of 12.5% for corn and save $28 per hectare in fertilizer costs. Besides this, ammonium sulphate derived from industrial ammonia (21% nitrogen) is also used for pH adjustment of acid soils. Experiments by the Central Soil Research Institute of India showed that treatment with 500 kg ammonium sulphate per hectare increased the soil pH from 4.8 to 5.5 and improved rice yield by 18%.
Pesticide and intermediate manufacture also depends on industrial ammonia. 50% of the world’s glyphosate production capacity is based on liquid ammonia, and each ton of glyphosate consumes 0.35 tons of industrial ammonia. In 2023, China’s glyphosate exports will reach 1.16 million tons, corresponding to the demand for industrial ammonia of about 406,000 tons. Studies by Bayer indicate that insecticides containing amino groups (e.g., imidacloprid) can reduce the incidence of insect infestation by 70%, but the residual concentration of ammonia nitrogen should be less than 0.2mg/L to avoid eutrophication of water bodies. EU’s Ammonia Emission Regulation for Agricultural Chemicals implemented in 2023 provides that the recovery rate of pesticide production ammonia shall not be less than 90%, promoting enterprises to renovate ammonia capture devices, and the cost of transforming a single production line is about 1.2 million euros, but operating costs can be reduced by 25%.
Industrial ammonia participates in hydrogen-energy coupled systems in green agricultural innovation. Japan’s Toyota Tsusho and Mitsubishi Heavy Industries joint cooperation in the development of the “green ammonia farm” project, through the use of renewable energy electrolytic water to generate hydrogen and then through the Haber process to synthesize zero-carbon industrial ammonia, 2025 pilot production capacity 30,000 tons/year, carbon emissions 92% lower than the conventional process. Australian CSIRO studies have demonstrated that the utilization of green ammonia in drip irrigation systems can boost the efficiency of nitrogen fertilizer delivery by 85% and decrease freshwater usage by 30%. While the initial capital cost of these technologies is as much as 2.3 times higher than conventional systems, the long-run returns can be between 8.5-12%, which aligns with the worldwide pattern of carbon neutrality in agriculture.