University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Rosemarie Wünscher
(2013):
A Comparison of Different Phosphorus Extraction Methods with the Phosphorus Uptake of Wheat.
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 84.
UB BOKU
obvsg
FullText
- Abstract:
- Phosphorus (P) is indispensable to life and therefore essential to plant nutrition. Rock phosphate reserves are limited demanding an optimization of the usage of P fertilizers. One step in this process is to find methods to determine the plant available P in soils accurately. The aim of this study was to identify P extraction methods best reflecting plant available P. Fifty agricultural soils were selected from Austria and Germany. Spring wheat was grown in a greenhouse pot experiment, harvested when mature and analyzed for yield parameters and P contents. The soils were extracted with the following methods/ extractants: H2O, CaCl2, LiCl, iron oxide impregnated filter papers, Olsen, calcium-acetate-lactate (CAL), cation and anion exchange membranes, Mehlich 3, Bray and Kurtz II, citrate-bicarbonate-dithionite, organic P, HCl, acid ammonium oxalate, total P. Phosphorus plant uptake was in the range of the P extracted by the weakest extraction agents. In general, the P values extracted by the 14 extraction methods significantly correlated with each other. Our results showed that H2O and CaCl2 extractable P correlated best with plant P uptake over one growing season. When grouping the soils according to pH, organic carbon content and clay content, weaker extraction methods showed analogous trends; also among the stronger extraction methods common tendencies were found. Based on my results I conclude that a single method may not be sufficient to assess current and potential plant availability of P and to reliably predict the necessity of fertilizer applications in agriculture.
- Beurteilende(r): Zehetner Franz