Título:	Nutrient concentration in soybean harvest residues in western Pará.
Autoria:	OLIVEIRA JUNIOR, R. C. de RODRIGUES, N. E. OLIVEIRA, D. R. de SANTOS, D. B. dos CARVALHO, E. J. M. VELOSO, C. A. C. SILVA, A. R.
Afiliação:	RAIMUNDO COSME DE OLIVEIRA JUNIOR, CPATU; NIELI ELOINE RODRIGUES, CENTRO UNIVERSITÁRIO LUTERANO DE SANTARÉM; DANIEL ROCHA DE OLIVEIRA, AGÊNCIA DE DEFESA AGROPECUÁRIA DO ESTADO DO PARÁ; DARLISSON BENTES DOS SANTOS; EDUARDO JORGE MAKLOUF CARVALHO, CPATU; CARLOS ALBERTO COSTA VELOSO, CPATU; ARYSTIDES RESENDE SILVA, CNPMS.
Ano de publicação:	2026
Referência:	Caderno Pedagógico, v. 23, n. 1, e22982, 2026.
Conteúdo:	The expansion of soybean cultivation in Eastern Amazonia poses challenges to the sustainability of soil management systems, particularly regarding nutrient cycling in highly weathered environments. This study aimed to quantify and compare macronutrient concentrations in soybean crop residues under no-tillage (NT) and conventional tillage (CT) systems in the Santarém Plateau, western Pará State, Brazil, and to assess their potential contribution to soil fertility. Crop residues were collected immediately after harvest using a 0.25 m² quadrat, in a completely randomized design with two treatments and ten replicates per system. After drying and grinding, samples were subjected to sulfuric acid digestion and analyzed by photometry to determine nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) concentrations. The results showed no statistically significant differences (p > 0.05) between management systems for the evaluated nutrients. The descending order of nutrient accumulation in the residues was K > N > Ca > Mg > P, highlighting potassium as the predominant nutrient in the crop residues, with values exceeding 40 kg ha⁻¹. Phosphorus exhibited extremely low concentrations, attributed to high export by grains and strong adsorption in dystrophic Yellow Oxisols. It is concluded that, in the short term, soil management systems do not substantially alter the nutritional composition of soybean crop residues. However, maintaining crop residues on the soil surface represents an important mechanism for nutrient cycling, particularly for potassium, while low phosphorus levels reinforce the dependence on mineral fertilization in Amazonian agricultural systems.
Thesagro:	Plantio Direto Resíduo
Palavras-chave:	Ciclagem de nutrientes
ISSN:	1983-0882.
Digital Object Identifier:	https://doi.org/10.54033/cadpedv23n1-215
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CPATU)