Figure 3

Scatterplots of predicted values and actual values of PXRF-quantified K content in Lubbock (A), pH content in Midland (B), PXRF-quantified Fe content in Amarillo (C), PXRF-quantified K content in Hobbs (D).

Scatterplots of predicted values and actual values of PXRF-quantified K content in Lubbock (A), pH content in Midland (B), PXRF-quantified Fe content in Amarillo (C), PXRF-quantified K content in Hobbs (D).