@article{gledocs_11858_7179, author = {Schellhorn, Matthias and Schenk, Manfred K. and Schmilewski, Gerald and Binner, Inga and Dultz, Stefan and Walsch, Jochen and Schmidt, Eva and Below, Malte and Meyer, Maike}, title = {Bedeutung von Toneigenschaften für die Wahl der Tonbeimengung in gärtnerischen Torfsubstraten}, year = {2013}, volume = {43}, pages = {19-38}, abstract = {Abstract: The purpose of adding clay to horticultural growing media is to achieve objectives such as a well-balanced nutrient supply, buffering of the pH-value, improvement of the rewettability, cohesion of the growing medium and supply of trace elements. Criteria for choosing clay types for specific applications are necessary to assess the suitability of original materials as well as processed clays in a reliable way. A wide range of clays for different applications was chosen for this study. Differences in the mineralogical composition and in pretreatment of the selected clays resulted in specific physical and chemical characteristics of the different growing media mixes. The influence of different clays on the rewettability and cohesion of growing media was analyzed in laboratory experiments which resulted in the definition of important parameters for selection of clays and suitable methods for processing. Clays with strong K and P fixation as well as clays with spontaneous release of these macronutrients were identified. The effects of clays on the flow of nutrients were documented in crop tests. growth-trials regarding Mn toxicity, carried out with clays with different contents of active Mn, proved that an existing RHP-threshold value for Mn in clays for growing media is not justified.}, note = { \url {http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/7179}}, }