Título:	Dynamics of potassium and phosphorus uptake in soybean cultivated on oxisol amended with biotite schist and potassium chloride.
Autoria:	MARCHI, G. FREITAS, E. M. de KRAHL, L. L. ABRANTES, E. G. de RODRIGUES, P. C. F. SOUZA-SILVA, J. C. SOARES, J. P. G. MARTINS, E. de S.
Afiliação:	GIULIANO MARCHI, CPAC; ELIS MARINA DE FREITAS; LUISE LOTTICI KRAHL; EWERTON GONÇALVES DE ABRANTES; PAULA CAROLINE FERREIRA RODRIGUES; JOSE CARLOS SOUSA SILVA, CPAC; JOAO PAULO GUIMARAES SOARES, CPAC; EDER DE SOUZA MARTINS, CPAC.
Ano de publicação:	2026
Referência:	Discover Soil, v. 3, article 64, 2026.
Conteúdo:	Abstract: Phosphorus (P) is an essential macronutrient for plant growth, but its availability to plants is often limited in acidic tropical soils by iron (Fe) and aluminum (Al) (hydr)oxides, which strongly adsorb and immobilize phosphate. This study evaluated soybean (Glycine max L. BRS 7582) growth in soil amended with biotite schist and a soluble potassium (K) source, potassium chloride (KCl). The experiment involved pots with dystrophic Rhodic Haplustox soil; treatments were composed by control, as KCl (KCl-T), 1% biotite schist (BSO) and biotite schist + 150 mg K kg⁻¹ as KCl (BS + KCl), with all treatments receiving 100 mg P kg⁻¹ as calcium dihydrogen phosphate [Ca(H₂PO₄)₂]. Results showed that KCl-T promoted greater shoot growth than the other treatments, presenting 9.0%, 11.9%, and 41.1% higher dry mass production compared to the BS + KCl, BSO, and control treatments, respectively. Across all sampling times, K concentration in soybean shoots was significantly higher in treatments receiving soluble K (KCl‑T and BS + KCl) than in the control (p < 0.001). Values ranged from 11.3 to 19.4 g K kg⁻¹ in KCl‑based treatments, whereas the control remained below 6.7 g K kg⁻¹ at all evaluation times, with BSO showing intermediate values. Notably, on the 47 day after planting, plant P uptake was statistically similar among BSO, BS + KCl, and KCl-T treatments (2.15 g P kg− 1; p < 0.0001). Soil P extractability, measured by Mehlich-1, after 37 and 47 days, increased 15.29 and 22.62% (both p < 0.0001) in the presence of biotite (BSO and BS + KCl), as compared to treatments without biotite (KCl-T and control); this pattern is consistent with an increase in oxalate‑extractable, poorly crystalline (short‑range ordered) Fe released during bioweathering, which may have contributed to P adsorption and Mehlich-extraction compared to crystalline iron/aluminum oxyhydroxides.
Thesagro:	Disponibilidade de Nutriente Potássio Adsorção Cloreto de Potássio Soja Glycine Max
NAL Thesaurus:	Nutrient availability Adsorption Potassium
Palavras-chave:	Soybean
Digital Object Identifier:	https://doi.org/10.1007/s44378-026-00215-y
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CPAC)