Fig. 3 Percentage of the whole ³¹P-nuclear magnetic resonance spectral area allocated to each particular P form in the size separates of the Taubenberg soils. Apart from these quantified P forms in the figure, traces of inorganic orthophosphate were detected in all clay separates, traces of phosphonates were detected in spruce forest (Sf) and deciduous forest (Df) clay, and a trace of pyrophosphate was found in permanent grassland (Gp) clay. Ar is arable rotation