A recent article in the journal Science focuses on soil—and on how we’re mistreating it. The article discusses soil’s role in regulating water and carbon cycles, and how changes in climate and food production are changing these interrelationships.
The article and this commentary on it also point out potentially catastrophic shortages in the years ahead: phosphorus and, to a lesser extent, potassium. Both, along with nitrogen, are essential for growing crops but in many places are becoming seriously depleted.
The nitrogen problem was solved more than a century ago, when scientists developed a way to remove nitrogen from the atmosphere and use it in fertilizers. The Haber process greatly increased the productivity of agricultural lands and helped speed the global increase in population—from fewer than 2 billion when the process was invented to more than 7 billion today.
A recent article in the journal Science focuses on soil—and on how we’re mistreating it. The article discusses soil’s role in regulating water and carbon cycles, and how changes in climate and food production are changing these interrelationships. The article and this commentary on it also point out potentially catastrophic shortages in the years ahead: phosphorus and, to a lesser extent, potassium. Both, along with nitrogen, are essential for growing crops but in many places are becoming seriously depleted. The nitrogen problem was solved more than a century ago, when scientists developed a way to remove nitrogen from the atmosphere and use it in fertilizers. The Haber process greatly increased the productivity of agricultural lands and helped speed the global increase in population—from fewer than 2 billion when the process was invented to more than 7 billion today. [text_ad] Phosphorus and potassium can be mined, but the largest phosphorus mine in the US will be depleted in the next 20 years. Shortages of phosphorus have caused the price to rise from $80 per ton in the mid-20th century to $700 per ton today. The price of potassium is expected to nearly double by 2020, to $1,500 per ton. A possible solution is recovering the nutrients from wastewater, although the process has some technical challenges of its own.
Phosphorus and potassium can be mined, but the largest phosphorus mine in the US will be depleted in the next 20 years. Shortages of phosphorus have caused the price to rise from $80 per ton in the mid-20th century to $700 per ton today. The price of potassium is expected to nearly double by 2020, to $1,500 per ton.
A possible solution is recovering the nutrients from wastewater, although the process has some technical challenges of its own.Janice Kaspersen
Janice Kaspersen is the former editor of Erosion Control and Stormwater magazines.
