Fig. 3. Phosphorus-31 nuclear magnetic resonance (31P NMR) spectra of NaOH–Na2EDTA extracts from soils either amended with solid poultry manure mixed with litter (A) or amended with calf slurry (B). MDP denotes the P standard.
Fig. 3. Phosphorus-31 nuclear magnetic resonance (31P NMR) spectra of NaOH–Na2EDTA extracts from soils either amended with solid poultry manure mixed with litter (A) or amended with calf slurry (B). MDP denotes the P standard.