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- Comportamento do fósforo em solos argiluviados da Região do Alentejo: sorção de fosfatoPublication . Monteiro, M.C.H.; Monteiro, Fernando; Madeira, ManuelO poster apresenta os resultaos de um estudo sobre o comportamento do fósforo em solos argiluviados da Região do Alentejo.
- Phosphate desorption in luvisols and solonetz from a Mediterranean regionPublication . Monteiro, M.C.H.; Monteiro, Fernando; Madeira, ManuelTransfer of P from soil to water is controlled by the P retention capacity in the solid phase, namely by the equilibrium between adsorbed and precipitated forms. Desorption of P and/or phosphate dissolution govern the amount of P released into drainage water, runoff or freshwater. Soil P evaluated by Olsen method showed a strong correlation with the capacity of soil to desorb P and, within certain limits, to the transfer of P to water. This transfer of P relates to losses that occur either in surface horizons, or in subsurface horizons (to drainage water, to runoff or by soil erosion to freshwater).
- Crop use and profile distribution of phosphorus in soils that developed on mafic rocks in southern PortugalPublication . Monteiro, M.C.H.; Monteiro, Fernando; Madeira, Manuel; Torrent, J.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 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.