Research Article

Effect of Land Application of Phosphorus-Saturated Gypsum on Soil Phosphorus in a Laboratory Incubation

Table 2

Treatments resulting from combination of phosphorus saturation level (expressed as a percent of the isotherm maximum) and gypsum application rate and the resulting application rates of phosphorus (P) and calcium (Ca), and their effect on soil water extractable P (WEP) and Mehlich 3 P (M3P) concentrations, averaged across time and soil type.

Treatment combinationPhosphorus saturation LevelGypsum application RateP application rateCa application rateGypsum application rateWEPM3P
% of maximum (Mg ha−1) (kg ha−1) (Mg ha−1) (mg kg−1)

LP-LG25%5.63512325.64.5 b61.9 c
HP-LG75%22.4105123222.47.1 b70.4 b
LP-HG25%5.614049285.66.6 b76.2 b
HP-HG75%22.4420492822.420.8 a117.3 a

, low phosphorus—high gypsum; HP-LG, high phosphorus—low gypsum; LP-HG, low phosphorus—high gypsum; HP-HG, high phosphorus—high gypsum.
followed by different letters were determined to be significantly different at .