University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Anna Schiefer
(2019):
Spatio-temporal pattern of Silicon fractions in Lower Austrian topsoils.
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 89.
UB BOKU
obvsg
- Abstract:
- Silicon (Si) has received increasing attention as plant nutrient during the last few years. Si is a very important factor for plant health and plant growth, alleviating biotic and abiotic stresses. Information about the Si concentrations in Austrian soils is not available apart from a recent master thesis conducted in our research group. This thesis aims to investigate spatial and temporal patterns of Si concentrations and explores influencing factors on soils Si status. The experimental work included the resampling of 84 Cambisols and related soils at sites in Lower Austria for which archived topsoil samples are available from the Austrian soil mapping campaign 20-40 years ago. Two different extractions methods were applied to distinguish between Si fractions. The potential plant-available Si was extracted with a diluted 0.01 M CaCl2 solution (Haysom and Chapman, 1975), the amorphous Si with 0.2 M NaOH (Georgiadis et al., 2015). The Si concentrations were measured using the molybdenum blue method and spectrophotometry (Morrison and Wilson, 1963). 51% of samples show plant-available Si concentrations below the upper limit of Si deficiency for sugarcane of <20 mg kg-1. Si concentrations remained consistently unchanged during the period of 1985 to 2017. High soil pH was significantly associated with high plant-available Si, but lower amorphous Si. Clayey soils correlate with high Si concentrations. Land use plays a significant role on plant-available and amorphous Si concentrations, with clearly lower amorphous and plant-available Si present in grassland as compared to arable soils, opposing the hypothesis of Si depletion in cultivated soils. Given the substantial number of soil samples with Si concentrations below the upper limit of Si deficiency for sugarcane, calibration of the 0.01 M CaCl2 extraction is required for Si accumulating crops, including grassland species, in temperate regions.
- Beurteilende(r): Wenzel Walter
- 1.Mitwirkender: Puschenreiter Markus