Monteiro, M.C.H.Monteiro, FernandoMadeira, ManuelTorrent, J.2018-09-212018-09-212018Monteiro, M.C.H. [et al.] (2018). Crop use and profile distribution of phosphorus in soils that developed on mafic rocks in southern Portugal. Archives of Agronomy and Soil Science. ISSN 1476-3567 online. P. 1-13.1476-3567http://hdl.handle.net/10400.11/6188The phytoavailability of soil phosphorus (P) depends on the different forms in which it occurs and how these forms change after the application of P fertiliser to the soil. Forms of P in the A, B and C horizons of eleven pedons that developed on mafic rocks were characterised by a fractionation method before and after fertilisation with single superphosphate, and a micropot experiment was conducted to assess the shortterm use of P fertiliser by rye (Secale cereale L.). The main sources of P to the crop were (i) phosphate adsorbed on mineral surfaces and pedogenic Fe, Al or Ca phosphates in the A horizon and (ii) Ca-phosphates in B and C horizons. In the C horizons, poor in Fe/Al phases and clay, the precipitated Ca-P showed low solubility, resulting in a reduction in shot biomass. The apparent P recovery by rye was similar in the A (36%) and B (29%) but decreased in the C (15%) horizons. The partial factor productivity (g g−1) decreased from the A (58) to B (11) and C (5) horizons. P phytoavailability decreased with increasing profile depth because the transformation of P fertiliser to poorly soluble Ca-P forms increased with depth.engOlsen PPhosphorus phytoavailabilityPhosphorus formsSoil phosphorus sinksSoil phosphorus sourcesjournal article10.1080/03650340.2018.1506920