Andreas Surböck

Comparing Hemp Seed Yields (Cannabis sativa L.) of an On-Farm Scientific Field Experiment to an On-Farm Agronomic Evaluation Under Organic Growing Conditions in Lower Austria

Abstract Hemp seed yields of the variety Fedora-19 in an on-farm scientific field experiment on small plots and in an on-farm evaluation in 11 hemp fields under practical organic growing conditions in Lower Austria were compared to give a realistic view of the variability of yields. Dry matter seed yields from the on-farm field experiment ranged from 127 to 143 g m−2. Under practical growing conditions, yields ranged from 34 to 151 g m−2 in the sample plots. The reported hemp seed yield after combine harvesting, drying, and cleaning was between 324 kg ha−1 and 717 kg ha−1. The results of the experiment show that harvesting by hand considerably influences yields. Yields of the manual harvest in sample plots indicate a high correlation with yields harvested by the combine harvester (R2 = 0.91). The commercial yield is 71% of the yields recorded in sample plots in the fields. Our data questions the transfer of results and conclusions drawn from the data of scientific field experiments that employ manual harvest to that of practical circumstances, and support the notion of on-farm research.

Hemp (Cannabis sativa L.) as a Resource for Green Cosmetics

Abstract The interest in hemp (non-drug Cannabis sativa L.) for skin care and cosmetic use is due to the high content of oil, especially unsaturated fatty acids in seed with technological and therapeutic effects. In a field trial on an organic farm, seed weight and content of fatty acids of 20 hemp varieties were surveyed on three different harvest dates. The dry matter seed yields ranged from 27-149 g m−2. The varieties Ferimon-12, Fedora-19, and Bialobreszie produced high seed yields on all three harvest dates but yields were not significantly different from a large group of other varieties. Contents of palmitic acid range from 3.1 to 4.1%, of stearic acid from 0.1 to 1.9%, of oleic acid from 3.7 to 9.2%, of linoleic acid from 44.8 to 60.2%, of a-linolenic acid from 18.2 to 27.4%, and of ?-linolenic acid from 1.6 to 4.7%. The genotype has no significant influence on fatty acid content. All 20 varieties tested show high quantities of fatty acid depending on the harvest date, so that no variety can be favored. Results confirm that hemp is a very good source of fatty acids for skin care and cosmetic use.

Management Effects on Quality of Organically Grown Winter Wheat

The potential for improving wheat grain quality by management strategies involving crop rotation, catch crops, and organic manure was tested in organic long-term experiments in Denmark and Austria. Growing grass clover in a four-year rotation resulted in a higher wheat yield increase that could not be achieved by including leguminous catch crops in the rotation. Yield was also higher with a pre-crop of pea than of lucerne. The average protein concentration was 132 g kg−1 for grains from the Austrian experiments while the Danish grains held 85 g kg−1. Protein was generally much less affected by the experimental conditions than grain yield. None of the tested management parameters affected grain protein concentrations in the Danish experiment. In the Austrian trial, a significant pre-crop × treatment interaction reflected a positive effect of the animal manure treatment on protein and dry gluten in wheat following pre-crop pea. Danish grains generally contained more soluble polymers of less interest for the baking process than the Austrian ones. The study emphasizes the challenges in improving the quality of organically grown wheat beyond what is predetermined by environmental growth conditions and cultivar. However, baking quality appeared better than could be expected from the quality parameters determined.

Einfluss der biologischen Bewirtschaftung auf die Phytodiversität in der Diasporenbank und oberirdischen Vegetation biologisch bewirtschafteter Ackerflächen

ZusammenfassungDas Projekt untersucht, ob die Umstellung landwirtschaftlicher Flächen auf biologische Bewirtschaftung die Vielfalt der Ackerbegleitflora erhält und fördert. Dazu wurden Untersuchungen an der oberflächlichen Vegetation und dem Diasporenvorrat auf Kleinparzellen durchgeführt. Diese wurden 2012 durch eine Umgebungskartierung der Vegetation rund um den Biobetrieb Rutzendorf ergänzt. Die Artenzahl der Ackerbegleitflora schwankt über die Jahre beträchtlich, doch insgesamt unterscheidet sich das Arteninventar nur geringfügig von jenem auf den umliegenden Flächen. Die Diasporenmengen korrelieren in ihrer Menge mit der Oberflächenvegetation und beide hängen wiederum stark von der angebauten Kulturart ab.AbstractThe project deals with the evaluation whether the conversion to organic farming leads to an increase of weed diversity. Additionally to the analysis of the above ground vegetation and the soil seedbank on the small permanent plots a mapping of the surrounding vegetation was conducted in 2012. The number of weed species varies highly over the years, but the inventory of species differs only slightly from the one found on the surrounding fields. The number of seeds per m² is highly correlated with the number of above ground weeds species. The crop has shown the highest influence on both.