Water balance found to influence soil pH and fertility

Water balance found to influence soil pH and fertility

Even casual fans of nature and environmental science understand that the pH level of soil is a major indicator of the soil’s ability to store nutrients and provide for vegetation growth. As such, soil pH serves as a significant controlling factor in the ultimate landscape of a terrestrial ecosystem. But a recent study published in the Nature journal highlights that pH soil does not regulate plant fertility on its own. Rather, environmental conditions can easily sway soil pH balance.

The study illustrates how even minor changes in water balance can quickly change the pH level from alkaline to acidic soils. Until now, however, it has not been clear how to quantify the exact threshold of soil pH balance. While topography and mineralogy are clear contributing factors, climate conditions appear to play an important overarching role.

A team led by J.E. Johnson of the Carnegie Institution for Science at Stanford University extracted a random sample from a compilation of 60,291 soil pH measurements. They found that the sudden transition from alkaline to acid soil pH occurs at the very point that mean annual precipitation starts to exceed mean annual potential evapotranspiration.

The team concluded that climate conditions can certainly create a nonlinear pattern in soil chemistry. Moreover, they indicate that the very conditions under which soil currently maintains pH balance are out of balance with modern climate.