Potassium availability to flooded rice in lowland soils

• Autor(a) principal: Silva, Leandro Souza da
• Data de Publicação: 2015
• Outros Autores: Pocojeski, Elisandra, Britzke, Darinês, Kaefer, Simone, Griebeler, Gustavo, Santos, Danilo Rheinheimer dos
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Tropical (Online)
• Texto Completo: https://revistas.ufg.br/pat/article/view/35437
• topic: Oryza sativa; sodium tetra phenyl borate; potassium absorption.; Oryza sativa; tetrafenil borato de sódio; absorção de potássio.

Non-exchangeable potassium (K) forms are not estimated by usual methods of soil K availability, like Mehlich-1, but they can contribute to K nutrition of flooded rice. This study aimed at evaluating K forms in lowland soils by different chemical methods and associate them to K absorption by flooded rice. Fourteen lowland soils cultivated with flooded rice (IRGA 417 cultivar) were sampled and used in a greenhouse experiment. The K forms in the soil samples were extracted before and after rice cultivation by using calcium chlorite, Mehlich-1, sodium tetra phenyl borate (NaTFB) and fluorite acid. The K uptake was measured in rice shoots. There was a wide variation in K forms among the lowland soils. The variation in the amount of K extracted by using the Mehlich-1 method does not explain the K absorption by irrigated rice plants in every soil. The NaTFB method was more sensitive to evaluate K availability in lowland soils cultivated with flooded rice plants.