History of Chemical Fertilizers

Overview

Farmers and gardeners have used fertilizers, such as manure, guano and even fish for thousands of years. The advent of modern chemistry offered a stable, easily delivered and safe way to improve crop yields. Since then, chemical fertilizers have been at the forefront of agriculture. Early discoveries indicated that saltpeter could improve soil. As science continued to develop, it was discovered that plants need certain chemicals to grow, leading to more effective fertilizers.

Early Discoveries

In the mid-1600s, scientist John Glauber developed the first chemical fertilizer, a combination of saltpeter, phosphoric acid and potash. In the 1800s, chemist Justus von Liebig demonstrated how plants need minerals such as nitrogen and phosphorous to grow. In 1842, Sir John Lawes outlined a method of treating phosphate rock with sulfuric acid to produce superphosphate, an effective fertilizer, and the start of the modern chemical fertilizer industry began.

Potassium Fertilizers

Another major step came with improved techniques for producing triple superphosphate in the late 19th and 20th centuries. European chemical companies began producing nitrophosphate fertilizer in the 1930s, which is still popular to this day. Ammonium phosphate fertilizers gained greater use in the 1960s because of improved manufacturing processes and are the most widely used phosphate fertilizers today.

Nitrogen Fertilizers

While nitrogen's role in plant growth was long understood, its use in chemical fertilizers was not considered important. Naturally occurring sources of nitrogen, such as guano, were considered adequate. As the population grew, however, more attention was given to nitrogen fertilizers. Advances in nitric acid production to make calcium nitrate, and the development of calcium cyanamide provided a more commercially available nitrogen fertilizer. In 1913, ammonia production on a commercial level began. While useful for making nitrogen fertilizers, other needs superseded any agricultural benefits. Instead, ammonia was used in explosives and industrial chemicals. After World War II, ammonia became more available and by the end of the 20th century, ammonium sulfate, calcium nitrate, sodium nitrate and calcium cyanamide were readily available. Ammonium nitrate became an important fertilizer during that time, eventually becoming the leader in fertilizers.

Potash Fertilizers

The earliest forms of potash fertilizers came from wood ash and saltpeter. Germany dominated the market for more than 75 years because of vast deposits of naturally occurring potassium salts. During the 20th century, more deposits were discovered elsewhere and exploited to increase availability. Refinement methods improved the quality of this resource. Today, high-grade potassium chloride is the result.

Compound Fertilizers

While early chemists experimented with using multiple ingredients, the fertilizer industry focused on the production of separate fertilizers, with only one primary constituent. In the United States, however, compound fertilizers gained in popularity and now are both widely accepted and distributed internationally. At first, these fertilizers were simple mixtures of superphosphate, guano, ammonium sulfate, potassium chloride and organic waste. In the 1930s, superphosphate was ammoniated to provide a more economical way to provide nitrogen. The world consumption of chemical fertilizers has continued to increase, with compound fertilizers seeing the greatest growth.

Modern Production

Production changes were implemented in the 1950s to accommodate using granular fertilizers. Fertilizer was bagged to allow for easier handling and shipping and continues to be provided in this form today. A trend toward using liquid and dry bulk fertilizers continues to expand to meet the needs of the large-scale production of today's agribusiness.