Benefits and risks of the utilization of grape pomace as organic fertilizers

Rhineland-Palatinate is Germany’s largest wine growing region. The recently launched collaborative project in the frame of the ‘Carl-Zeiss-Stiftungs-Kooperationsfonds für Nachhaltigkeitsforschung’ focusses on the risk-benefit assessment of the use of grape pomace (GP) from the region ‘Pfalz’ in Rhineland-Palatinate as a natural fertilizer.GP contains high loads of bioactive compounds such as polyphenols and macro- as well as micronutrients which make GP an attractive, low-cost fertilizer [1,2]. On the other hand, GP may also contain residues of pesticides and mycotoxins. Their presence is undesirable in wine as well as in a potential fertilizer [3,4]. The application of high amounts of the above mentioned substances at once could negatively affect plant quality and microbial soil communities [5]. Therfore, the agricultural value of GP as a fertilizer could be limited by the transfer of these compounds into the soil. Up to date, little is known about the influence of GP constituents on the soil quality and processes, especially in a long-term exposure.In this project, we aim to determine the contents of polyphenols, mycotoxins, and pesticides in addition to the macro- and micronutrient content of GP from six different grape varieties. Furthermore, the effect on important soil parameters, such as nutrient availability, hydrodynaics, and microbiology will be analysed and evaluated.

Authors: Sullivan Sadzik¹, Korz Sven², Buchmann Christian², Richling Elke¹ and Munoz Katherine²

¹TU Kaiserslautern, Department of Chemistry, Division of Food Chemistry and Toxicology 
²Universität Koblenz-Landau, Campus Landau, Germany 

*corresponding author: Sullisadzik@rhrk.uni-kl.de

References:
[1] E. Nistor, A. Dobrei, E. Kiss, V. Ciolac, Journal of Horticulture, Forestry and Biotechnology 18, 141 (2014).
[2] C. Fuchs, T. Bakuradze, R. Steinke, R. Grewal, G.P. Eckert, E. Richling, Journal of Functional Foods 70, 103988 (2020).
[3] J.E. Welke, Current Opinion in Food Science 29, 7 (2019).
[4] X. Hou, Z. Xu, Y. Zhao, D. Liu, Journal of Food Composition and Analysis 89, 103465 (2020).
[5] C. Buchmann, A. Felten, B. Peikert, K. Muñoz, N. Bandow, A. Dag, G.E. Schaumann, Plant Soil 386, 99 (2015).

Keywords: soil, grape pomace, fertilizer, polyphenols, mycotoxins