Arrobas, MargaridaRaimundo, SoraiaSawimbo, AlmeidaRodrigues, NunoJongen, MarjanTeixeira, Ricardo F.M.Domingos, TiagoRodrigues, Manuel Ângelo2026-01-202026-01-202025Arrobas, Margarida; Raimundo, Soraia; Sawimbo, Almeida; Rodrigues, Nuno; Jongen, Marjan; Teixeira, Ricardo F.M.; Domingos, Tiago; Rodrigues, Manuel Ângelo (2025). Evaluating soil phosphorus tests and nutrient limitations in Mediterranean pastures. Sains Tanah - Journal of Soil Science and Agroclimatology. ISSN 2356-1424. 22:2, p. 444-4562356-14241412-3606http://hdl.handle.net/10198/35546Reliable phosphorus (P) fertilization guidelines for Mediterranean pastures remain uncertain due to inconsistent soil testing methods, the complexity of mixed-species systems, and the neglect of other limiting nutrients. This study primarily aimed to identify reliable soil P tests and secondarily to explore potential nutrient limitations by assessing seven acidic Portuguese soils under Mediterranean conditions using subterranean clover (Trifolium subterraneum) and ryegrass (Lolium multiflorum) as model species. Five P extraction methods (Egner-Riehm, Olsen, Bray II, Mehlich I, and anion exchange resin) were compared alongside a pot experiment with clover, ryegrass, and their mixture. Biomass production, plant nutritional status, and soil-plant relationships were used to assess nutrient availability and plant response. The Egner-Riehm method proved the most reliable, showing linear correlation with the resin method (R2 = 0.89), widely regarded as the best indicator of soil P bioavailability. P availability was therefore not a limiting factor for biomass production. The lowest soil P content (54 mg kg-1 P2O5, Egner-Riehm) was close to the medium threshold (50-100 mg kg-1), yet plant growth indicated adequacy. In contrast, nitrogen (N) emerged as the main growth constraint, and boron (B) deficiency further restricted clover performance, confirming additional nutritional imbalances. A linear relationship between soil and tissue B supported its association with DMY, and tissue B levels were below sufficiency thresholds. Overall, in acidic Portuguese soils under Mediterranean conditions, soil P was adequate, whereas N and B acted as key constraints to productivity. These findings support more accurate and efficient fertilization strategies for Mediterranean pastures.engLolium multiflorumPasture fertilizationResin-PSoil phosphorusTrifolium subterraneumjournal article10.20961/stjssa.v22i2.108545