Soil phosphorus stocks could prolong global reserves and improve water quality

Combining existing databases, we estimated global phosphorus stocks in croplands and grasslands that are not readily available to plants as 32–41% of the 2020 estimated geologic phosphorus reserves, representing 146–186 years of the 2020 mass of phosphorus fertilizer applied annually. Especially if accessed by more efficient crops, this stock could reduce the need for additional fertilizer, improve water quality and contribute to all-round phosphorus sustainability. Combining existing databases, this study estimates global phosphorus stocks in croplands and grasslands that are not readily available to plants. The reserves represent 146–186 years of the 2020 mass of phosphorus fertilizer applied annually.