Soybean potassic fertilization in a Dark-Red Latosol sandy loam

• Autor(a) principal: Rosolem, Ciro A.
• Data de Publicação: 2014
• Outros Autores: Nakagawa, João, Machado, José R.
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Brasileira (Online)
• Texto Completo: https://seer.sct.embrapa.br/index.php/pab/article/view/16149
• topic: Glycine max; potassium; sources; way of application; levels in the soil; leaf contents; leaching; Glycine max; potássio; fontes; modo de aplicação; níveis no solo; níveis na planta; lixiviação

During three years, an experiment was carried out in a Dark-Red Latosol (sandy loam) to study the effects of annual applications of 0, 40, 80, 160 and 240 kg/ha of K2O as potassium chloride and potassium sulphate, applied in the seed rows or spread and incorporated. There was a yield increase due to potassium fertilization since the second year. Maximum yields were associated to potassium levels in the leaves above 1.5% In drier than normal years, the spreading applications led to better results than row applications. There were no differences between potassium sources. A decrease in exchangeable potassium levels in the soil was observed; for this reason, the application of doses bigger than 80 kg/ha of K2O a year was considered necessary to maintain the original potassium level. On the other hand, the fertilization with higher potassium doses led to a significant loss of potassium by leaching.