Wednesday, January 8, 2014

Many Countries Reaching Diminishing Returns in Fertilizer Use

When German chemist Justus von Liebig demonstrated in 1847 that the major nutrients that plants removed from the soil could be applied in mineral form, he set the stage for the development of the fertilizer industry and a huge jump in world food production a century later.

Growth in food production during the nineteenth century came primarily from expanding cultivated area. It was not until the mid-twentieth century, when land limitations emerged and raising yields became essential, that fertilizer use began to rise.

The growth in the world fertilizer industry after World War II was spectacular. Between 1950 and 1988, fertilizer use climbed from 14 million to 144 million tons. This period of remarkable worldwide growth came to an end when fertilizer use in the former Soviet Union fell precipitously after heavy subsidies were removed in 1988 and fertilizer prices there moved to world market levels. After 1990, the breakup of the Soviet Union and the effort of its former states to convert to market economies led to a severe economic depression in these transition economies. The combined effect of these shifts was a four-fifths drop in fertilizer use in the former Soviet Union between 1988 and 1995. After 1995 the decline bottomed out, and increases in other countries, particularly China and India, restored growth in world fertilizer use.

As the world economy evolved from being largely rural to being highly urbanized, the natural nutrient cycle was disrupted. In traditional rural societies, food is consumed locally, and human and animal waste is returned to the land, completing the nutrient cycle. But in highly urbanized societies, where food is consumed far from where it is produced, using fertilizer to replace the lost nutrients is the only practical way to maintain land productivity. It thus comes as no surprise that the growth in fertilizer use closely tracks the growth in urbanization, with much of it concentrated in the last 60 years.

The big three grain producers—China, India, and the United States—account for more than half of world fertilizer consumption. In the United States, the growth in fertilizer use came to an end in 1980. China’s fertilizer use climbed rapidly in recent decades but has leveled off since 2007. In contrast, India’s fertilizer consumption is still on the rise, growing 5 percent annually. While China uses 50 million tons of fertilizer a year and India uses 28 million tons, the United States uses only 20 million tons. (See data.) More