Mechanical impedance in growing media under different hydric tensions

• Autor(a) principal: Fermino, Maria Helena
• Data de Publicação: 2006
• Outros Autores: Kümpf, Atelene Normann
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Gaúcha (Online)
• Texto Completo: http://revistapag.agricultura.rs.gov.br/ojs/index.php/revistapag/article/view/267
• topic: penetrometer, peat, pine bark.; micropenetrômetro, turfa, casca de pinus.

This study was performed to evaluate the influente of the usually most applied water,tensions on the mechanical impedance of growing media. Six substrates were used: three types of the peat - black (BP), brown (Bill and rcd peat (RP) - and three commercial mixtures based on pine bark, indicated for vegetables (V), forest (F) and tobacco pin‘tlets (T). The samples were set in cylinders, saturated and submitted to five moisture tensions: 1 0, 30, 50, 80 e 100 hPa. The mechanical impedance was measured with a penetrometer five times in each sample, at 2 cm depth. Increasing water tension increased the mechanical impedance, with different curve responses for each material. The lower mechanical impedance was obtained at 10 hPa(clirresponding to the concept of container capacity).