Phosphorus biogeochemistry regulated by carbonates in soil

Area of Science:

• Soil Science
• Biogeochemistry
• Environmental Chemistry

Background:

• Phosphates are the primary source of phosphorus (P), a crucial element for ecosystems.
• Available P in soils is often deficient, particularly in carbonate-rich environments, indicating a link between P and carbon (C) biogeochemistry.
• Understanding the interplay between carbonates and P is vital for soil fertility and ecosystem health.

Purpose of the Study:

• To review the multifaceted influences of carbonates on the phosphorus cycle.
• To explore both abiotic and biotic pathways through which carbonates affect P availability.
• To elucidate the complex interactions between carbonate and P biogeochemistry in soil systems.

Main Methods:

• Review of abiotic processes: element release, transport, sorption, desorption, weathering, and precipitation.
• Examination of the sorption of P onto carbonates and their buffering capacity.
• Analysis of biotic factors, including microbial roles in P cycling and interactions with carbonates.

Main Results:

• Carbonates influence P availability through geochemical processes like sorption and precipitation.
• Microbial activity, influenced by organic C derived from carbonates, plays a significant role in P turnover.
• Extracellular calcium-phosphate precipitation and microbial bioweathering/biomineralization further complicate P and carbonate dynamics.

Conclusions:

• Carbonates may negatively impact the supply of available P in soil ecosystems.
• The intricate regulation of P biogeochemistry by carbonates has implications for predicting long-term P availability.
• This review underscores the critical role of carbonate-P interactions in soil C and P cycles.