Taciana Frigotto

Compactação do solo causada por tratores florestais na colheita de Pinus taeda L. na região sudoeste do Paraná

Soil compaction has been becoming one of the main impacts caused by mechanized harvesting activities. The weight and movement of machines at the time of cutting and loading timber combined with the inappropriate moisture condition of the soil are the main causes of soil structural degradation, observed mainly by changes in physical properties. Thus, this work aimed to identify soil compaction caused due to forest harvesting of Pinus taeda L. performed on three different soil moistures. The study was conducted in the operational areas of a forestry company located in Parana on red latosol. The treatments consisted of the interaction of three factors: moisture (rainy day harvesting and 3 and 7 days after rain), harvesting operations (machine traffic, no machine traffic/eventual timer landing and yard), and time of collection (before and after harvest). The residual biomass from forest harvesting was essential to minimize soil compaction caused by machinery traffic that was close to the maximum. The gradation of soil moisture represented by the different days of harvest after a rain did not influence differently the soil compaction. However, harvesting operations impacted soil to a depth of 10 cm causing compaction on the traffic lines of the machines, while the others operations did not cause changes in density, macroporosity and resistance to penetration.

Development and nutrition of black wattle seedlings (Acacia mearnsii de Wild. De Wild.) in poultry litter substrate

We evaluated the development and the nutritional status of Acacia mearnsii De Wild. seedlings produced in four organic substrates with poultry litter base, distributed in percentage terms: T1: 25CA:50S:25A; T2: 50CA25S25A; T3: 25CA75S and T4: 100SC (CA: poultry litter; S: soil; A: sand; SC: commercial substrate), in tubes of 125 cm 3 conducted in greenhouse / shade area. The best results, to the morphological variables height, stem diameter, number of leaves, dry mass of roots and total, were obtained in commercial substrate and in between 25 to 50% of poultry litter with clay soil and sand. The N and Mg contents (shoot and roots) and P and K (shoot) were not influenced by substrates. In the roots, the P content was greater on treatment with biggest proportion of clay soil. The K, in the roots, had the highest levels in substrates composed of 25 to 50% of poultry litter and commercial substrate. For Ca, the contents in shoots were higher than roots, mainly in the substrates with up to 50% of poultry litter. In the roots, the proportion of poultry litter did not influence Ca. The tested substrates, generally, did not influence the nutritional status of the seedlings.

Desenvolvimento de mudas de Schizolobium amazonicum Huber ex Ducke em diferentes ambientes em viveiro

O objetivo do estudo foi avaliar o desenvolvimento de mudas de Schizolobium amazonicum sob o efeito de diferentes ambientes de viveiro, nos seguintes tratamentos: T1- mudas a pleno sol, T2 - mudas em casa de sombra (75%) e T3 - Casa de vegetacao. As variaveis analisadas foram: indice de sobrevivencia, altura da parte aerea (h), diâmetro do colo (dc) e numero de folhas (nf). O crescimento em altura foi maior na casa de vegetacao (50,3 cm), semelhante na casa de sombra (49,0 cm) e inferior nas mudas a ceu aberto (46,2 cm). Quanto ao diâmetro de colo, as mudas da casa de vegetacao tiveram crescimento maior (6,6 mm), semelhante na casa de sombra (6,3 mm), e superiores a ceu aberto, com o menor crescimento (5,2 mm). O numero de folhas na casa de vegetacao apresentou os melhores resultados (3,9), seguidos pela casa de sombra (3,5), os quais foram superiores ao tratamento a ceu aberto (0,3). Conclui-se que as mudas de parica podem ser produzidas em casa de vegetacao ou em casa de sombra, porem nao a ceu aberto, devido aos danos do frio as mudas.