Horta, Carmo Monteiro, Fernando Madeira, Manuel Torrent, José Crop use and profile distribution of phosphorus in soils that developed on mafic rocks in southern Portugal <p>The 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 short-term use of P fertiliser by rye (<i>Secale cereale</i> 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 shoot 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<sup>−1</sup>) 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.</p> Olsen P;phosphorus phytoavailability;phosphorus forms;soil phosphorus sinks;soil phosphorus sources 2018-08-17
    https://tandf.figshare.com/articles/journal_contribution/Crop_use_and_profile_distribution_of_phosphorus_in_soils_that_developed_on_mafic_rocks_in_southern_Portugal/6979220
10.6084/m9.figshare.6979220.v1