Farmers have long known one of the best ways to increase crop production is to add nutrients to the soil. Development and adoption of concentrated synthetic fertilizers, along with plant breeding, irrigation and other technologies, helped fuel the Green Revolution during the middle of the 20th Century.
However, growing demand for food and biofuels in coming years could challenge our ability to produce enough nitrogen, phosphorus and potassium to support higher yields, according to a new report from the Council for Agricultural Science and Technology (CAST). Efficient use of nutrients, and recovery and recycling of nutrients from farm and non-farm sources will need to continue to improve, say the authors of the report titled “Food, Fuel, and Plant Nutrient Use in the Future.”
Key points in the report include:
- With a growing population, dwindling arable land, and an increased demand for biofuels, the world cannot count on an expansion of harvested area to fill the demands.
- Grain production will need to increase by approximately 50 percent during the next four decades. Current U.S. growth rates in cereal yields should meet 2050 demands, but greater yields per unit land area require increases in fertilizer nutrient use, advances in genetics, and improved soil and crop management technologies.
- Per-capita consumption of calories will stabilize during the next 40 years, but the composition of diets will change substantially. Consumption of cereal grains will stabilize, while global consumption of meat and dairy products will increase by more than 30 percent.
- In developed countries, the increase in consumption of animal products over the next 40 years will be a modest 8 percent, but in developing countries it will increase by 70 percent.
- Although cereal consumption among humans will stabilize in developed and developing countries, total cereal consumption will increase substantially due to increased feed use.
- In the United States, removal of nitrogen, phosphorus, and potassium from soils has been increasing, and there is a need for increased fertilizer use and more recovery and recycling from farm and nonfarm systems. Commercial fertilizers are responsible for 40 to 60 percent of current U.S. food production.
- Additional nutrients removed from cropping systems as a result of bioenergy production will intensify the need for more balanced P and K budgets. The Future P and K fertilizer use will need to increase or more nutrients will need to be recovered and recycled.
- If nitrogen use follows the trend of the last 20 years, it will increase 44 percent by 2050. Improved N use efficiency could lessen this increase but likely will not eliminate it.
- Nitrogen-fertilizer production uses N from the air and fossil fuels such as natural gas to create ammonia. The ammonia is then either directly applied or used to manufacture other N fertilizer products. Development of new natural-gas sources and resulting lower gas prices likely will reverse the trend toward higher nitrogen prices.
- Commercial phosphate fertilizers are processed from mined P2O5 rock. The United States currently is second only to China in P2O5 rock production and contributes more than 15 percent of the world’s phosphate mining.
- Based on rock value, cost of extraction, and 2009/2010 mine production, the U.S. Geological Survey has estimated U.S. P2O5 reserve life at 53 years. However, those estimates increase if higher phosphate prices make additional mineral resources economically viable.
- Potash (potassium oxide) is also mined from extensive geological deposits. More than one-fourth of the world’s K2O production comes from Canada, and nearly half the world’s known K2O reserves are located within its borders. World K2O reserve life is estimated at 353 years at 2009/2010 production levels.
- The world supply of raw materials needed for fertilizers should be sufficient to meet anticipated growth in demand. Future P and K needs in the United States will be met to an increasing extent by imported raw materials or final products, whereas future N needs could be met primarily by North American production.
The full report is available free as a download or in print from the CAST website.