Research Article

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

Table 3

Effect of soil type and time on soil water-extractable phosphorus and Mehlich 3 phosphorus concentrations averaged across phosphorus saturation level and gypsum rate.

Soil typeDays after Amendment
(mg kg−1)

Soil water extractable phosphorus concentration

Sandy loam17.8 a14.3 ab14.1 ab15.0 ab9.4 bc9.5 bc9.1 bc
Silt loam12.8 ab8.0 bc6.5 bc5.6 bc5.3 c4.8 c4.6 c
Unamended sandy loam6.
Unamended silt loam5.

Soil Mehlich 3 phosphorus concentration

Sandy loam73.2 d57.6 d98.3 bc111.8 ab127.1 a87.2 c83.5 c
Silt loam64.2 d62.3 d68.9 d107.2 b91.1 c58.5 d50.0 d
Unamended sandy loam49.354.957.082.199.762.960.7
Unamended silt loam41.035.642.077.869.842.237.8

followed by different letters were determined to be significantly different at . Means for the unamended soils were not compared statistically to the amended soils.