Crop residues can be a potential source for available phosphorus (P) to plants, but the influence of crop residue quality on the dynamics of available P and P uptake by plants is not well studied in Australian soils. The objectives of this study were to assess the relationships between residue characteristics (differing in nutrient contents, carbon quality and developmental stage) on soil P availability and plant P uptake. In this study, 10 crop residues from 6 crop species (canola, pea, lupin, lucerne, lentil and wheat) grouped into young (5), mature (4) and root (1) residues were added at 10 mg P kg^-1 to a P deficient (P_resin 1.3 mg P kg^-1 soil) sandy loam soil incubated at 85% water holding capacity in the glass house at 10°C/18°C, 8 h night/16 h day for 84 days. Additional treatments included triple super phosphate (TSP) at 10 mg P kg^-1 and an unamended control. The initial characteristics of crop residues were determined by solid-state ¹³C nuclear magnetic resonance (NMR) spectroscopy and wet chemical analysis. Wheat plants (Triticum aestivum cv. Yitpi) were grown for 4 weeks each during 3 consecutive growth periods. During incubation, soil samples were periodically analyzed for available P (P_resin), microbial P (P_mic), biomass C (C_mic). Soil respiration, plant dry matter (DM) yield and P concentration in shoot and root were also determined. P_resin concentration in soils decreased in the following order: TSP>root³young>control>mature, whereas P_mic concentration ranked in an approximately opposite order: mature>young³root>TSP³control. P_resin in residue amended soil was correlated positively with total P and P_H2O concentration in the residues and negatively with residue C: P, lignin: N, and phenolics: N ratios, whereas P_mic was correlated negatively with total P and P_H2O concentration of residues and positively with the C: P, lignin: N, phenolics: N ratios of residues and C_mic. Generally, shoot and root DM yield of wheat ranked in the order TSP>root³young³control>mature during the 3 growth periods. Shoot and root P concentration in the plants was lower in plants grown in soil amended with mature residues than in all other treatments. Shoot and root P concentration were positively correlated with the P concentration in the crop residues. The results of this study show that young residues with low C: P ratio (132 - 252) have potential for increasing P availability and P uptake by plants. On the other hand, mature residues with high C: P ratio (504-874) lead to prolonged P immobilization, since even in the last growing period of the pot experiment (63-84 days after amendment), P_resin and plant P uptake were still below values in the control treatment. Therefore, addition of crop residues can improve soil nutrient cycling while the value of their contribution depends on the chemical and biochemical properties of the residues.