Microtopographies and soil conditioners on growth and nutrition of </i>Eucalyptus saligna</i> in abandoned agricultural field

Rehabilitation of abandoned agricultural fields is a multidisciplinary task, in pursuit of the development of sustainable productive systems. The objective of this study was to evaluate the effect of microtopography technique and soil conditioners on survival, growth and nutrition of Eucalyptus saligna of an abandoned agriculture field. Plots of microtopography and flat plots were established in an abandoned agriculture field (27º 12.08' S and 49º 07.60' W). Within plots, we stablished subplots with plants, which received the application of soil conditioners, including phonolite (100 g), mycorrhizal inoculant (200 cm3), pulp sludge and carbonized rice husk (200 cm3), phonolite (100 g) and mycorrhizal inoculant (200 cm3) and control. The experiment monitoring occurred between november 2013 to october 2014 and growth parameters were measured after 30, 90, 150, 210, 270 and 330 days of the experiment onset. From each plant, height, stem diameter and canopy area were measured. At the end of the experiment, 50 leaves were collected from each plant to determine potassium and phosphorus concentrations. The native mycorrhizal community was characterized by bioassay and species identification of field-collected spores. Survival rates of Eucalyptus saligna tended to be higher in microtopography plots. The Plant height, stem diameter, canopy area, and shoot P and K concentration were significantly higher in plants at microtopography plots. Soil conditioners influenced significantly the shoot K concentration. The application of microtopography technique improved survival, growth, and nutrition of Eucalyptus saligna, and it represents an important strategy to rehabilitate abandoned agricultural fields.