Global phosphorus shortage will be aggravated by soil erosion

TLDR

Soil phosphorus loss from agriculture threatens future food and feed production, as global soils are already being depleted despite high fertilizer use, with Africa, South America, and Eastern Europe experiencing the highest depletion rates. The study aims to assess global soil phosphorus loss by combining spatially distributed erosion estimates with cropland soil phosphorus content. The authors use spatially distributed global soil erosion estimates (sheet and rill erosion) and cropland soil phosphorus data to quantify soil P loss. Projected future mineral phosphorus shortages will deplete agricultural soils by 4–19 kg ha⁻¹ yr⁻¹, with water‑erosion losses accounting for over half of total phosphorus loss.

Abstract

Abstract Soil phosphorus (P) loss from agricultural systems will limit food and feed production in the future. Here, we combine spatially distributed global soil erosion estimates (only considering sheet and rill erosion by water) with spatially distributed global P content for cropland soils to assess global soil P loss. The world’s soils are currently being depleted in P in spite of high chemical fertilizer input. Africa (not being able to afford the high costs of chemical fertilizer) as well as South America (due to non-efficient organic P management) and Eastern Europe (for a combination of the two previous reasons) have the highest P depletion rates. In a future world, with an assumed absolute shortage of mineral P fertilizer, agricultural soils worldwide will be depleted by between 4–19 kg ha −1 yr −1 , with average losses of P due to erosion by water contributing over 50% of total P losses.