The relationship between runoff and soil phosphorus concentrations in a benchmark soil of the southern piedmont

Abstract

The relationship of P in runoff from simulated rainfall and soil test P (STP) was studied on Cecil and associated soils at six field sites. The strongest relationship (R2 = 0.692) between STP and P in field runoff was obtained with BAP soil test on 5 cm soil samples and BAP in runoff. MIII STP and Total P in runoff was also highly correlated (R2 =0.682) at the 5 cm level. Laboratory rainfall simulations were conducted for comparison to field simulations. ANOVA was performed and no significant relationship was found with average field and laboratory P runoff values versus STP methods. To account for runoff variability, field and laboratory data were normalized by dividing by the depth of runoff. ANOVA was again performed and relationships between field and laboratory were significant (P >0.05). Therefore, when runoff variability is accounted for, no significant difference existed between field and laboratory studies.