Abstract
In the present study, we evaluated the effects of surface application and plowing of phosphogypsum and turkey
litter to a depth of 20 cm on the erodibility of clay-illuvial agrochernozem (Luvic Chernozems (Aric, Pachic)) in the
Southern Cis-Urals (Republic of Bashkortostan, Russia). Under laboratory conditions, 1°, 3°, and 7° slopes were
modeled. Soil loss, runoff onset time, and turbidity were measured with a rainfall simulator. Particle size
distribution and total organic carbon were measured. Under simulated heavy rainfall (360‒420 mm h−1) for 30 min,
the untreated control had the highest soil loss (28.9 t ha−1). Separate and combined introductions of phosphogypsum
and turkey litter significantly increased soil resistance to water erosion. Co-introduction of the amendments
strengthened this effect especially when the phosphogypsum to turkey litter ratio increased from 1:10 to 1:2 at the
higher dose (60 t ha−1). The turbidity of the runoff from a 1° slope reached a small peak within the first 3 min then
gradually decreased thereafter. At 3°, the turbidity remained nearly constant over time and was uniformly
distributed. At 7°, the turbidity sharply increased then gradually decreased and its distribution was a deformed bell.
Washed-out (trapped) sediments from all treatments and slopes had relatively more very fine sand, silt, and clay and
a slightly higher total organic carbon content than the original soil. Phosphogypsum and turkey litter wastes may be
effective anti-erosion amendments and potential fertilizers because they increase flocculation, improve the structure,
and enrich the organic matter and nutrient content of the soil.
