The moderately high loadings were pH, silt fraction, and residual P. The statistical
correlations between underlying variables indicated that soils with low levels of exchangeable bases
and correlatively low pH had higher levels of NaOH-Pi and residual P. The third component which
explained 13.7% of TSV was dominated by texture, oxalate-extractable Fe, and P sorption. The last
component emphasized dominantly HCl-P. Analysis of variance of the scores of the 4 PCs showed a highly
significant difference (P = 0.000) between soil types for PC1 and PC2 (Fig. 2). Principal component 3
scores differed significantly across soil types (P = 0.013) while the 4th component showed no statistical
difference across soil types. Correlation analyses with DMY as the dependant variable indicated that
PC1 was the only soil quality that significantly (P = 0.015) correlated with DMY.