University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Johannes Tobias Wedenig
(2017):
Auswirkungen der Produktionsweise "Geschützter Bio-Fruchtgemüsebau" auf chemische Bodenparameter
Nährstoffbilanzierung und Bodenanalysen.
Master / Diploma Thesis - Institut für Ökologischer Landbau (IFÖL),
BOKU-Universität für Bodenkultur,
pp 89.
UB BOKU
obvsg
FullText
- Abstract:
- Organic greenhouse vegetable production is a highly intensive production system. High nutrient demands due to high yields require high nutrient inputs via different fertilizers. Actors in this system find totally different circumstances compared to organic systems outdoor. The typical “tools” used in organic farming like crop rotation or green manure which provide soil fertility are hardly used because the infrastructure is so expensive that it is simply uneconomic. To gain insight how nutrient flows look like in this kind of production system, this study analyzed nutrient flows of five organic horticultural farms in Austria. To find out how soil properties change if soils were cultivated in a different production system, soil samples were taken from inside and outside greenhouses to examine various parameters like soil pH, salinity, soil organic matter content, nutrient contents, etc. It was ascertained that all farms show strong imbalances in their nutrient flows with high average surpluses for all nutrients (249 kg ha-1 a-1 for nitrogen, 53 kg ha-1 a-1 for phosphorus, 161 kg ha-1 a-1 for sulfur) except potassium with an average deficit of 93 kg ha-1 a-1. The analyses of the soil samples revealed that many parameters show a significant difference between the soil samples from inside and outside the greenhouses. The method “greenhouse vegetable production” has lead to an accumulation of soil organic matter and to a strong increase in soil salinity (from 0.4 mS cm-1 outdoor to 3.9 mS cm-1 inside the greenhouse). Several nutrients (N, P, K, Ca, Mg, S) have been accumulating in the topsoil and appear in huge quantities (e.g. 951 kg K ha-1 which is accessible for plants). The ratios among the nutrients has changed in an unfavorable way. The results show that within this intensive production method it is very challenging to achieve a balanced fertilization and to create a sustainable system, which is the point of organic philosophy.
- Beurteilende(r): Friedel Jürgen Kurt