1 The effect of a terra preta-like soil improver on the germination and growth of radish and parsley N. Andreev 1 , M. Ronteltap 1 , B. Boincean 2 , P. Lens 1 1 UNESCO-IHE Institute for Water Education. Westvest 7, 2611 AX Delft, The Netherlands, n.andreev@unesco-ihe.org, m.ronteltap@unesco-ihe.org, p.lens@unesco-ihe.org 2 Research Institute for Field Crops, Selectia, 28 Calea Ieșilor str., MD 3101 Baltsy, Moldova Cite as: Andreev, N.; Ronteltap, M.; Boincean, B.; Lens, P., The effect of a terra preta-like soil improver on the germination and growth of radish and parsley, in: Bettendorf, T.; Wendland, C; Otterpohl, R. 2014. Terra Preta Sanitation. Publisher: Deutsche Bundesstiftung Umwelt ISBN 978-3-00-046586-4 http://www.terra-preta-sanitation.net Abstract Phytotoxicity tests are important for the evaluation of efficacy of soil improvers. The current research evaluates the effect of fermented human faeces, charcoal and terra preta-like soil improver (mix of the two components) as well as the vermicomposted terra preta-like soil improver on the germination and growth of radish and parsley. The germination test was performed by treating the radish seeds with a liquid of lacto-fermented human faeces, charcoal and mix of the two components at different mass fractions (0.5, 1, 2, 4 and 6 per cent to water). For the control, dechlorinated water was used. The parsley seeds were sawn directly in soil (control) and mix of soil: terra preta-like soil improvers at 3:1 by volume. The terra preta-like soil improver has contributed with higher growth rate in parsley than the control, also more seedlings survived at the end of experiment than those in control (92 versus 70 per cent). The effect of the terra preta- like soil improver, including the vermicomposted one was superior to charcoal and lacto-fermented material alone. The current study demonstrated the lack of toxicity and usability of this soil improver for soil and its potential beneficial effects on crops. Keywords: Terra preta like substrate, lactofermented human faeces, charcoal, phytotoxicity, germination index, shoot growth INTRODUCTION Terra preta sanitation technology is an emerging technology that can open interesting perspectives for production of high quality soil improvers. By lacto-fermenting human excreta it is possible to return greater amount of carbon and nitrogen to the soil than stored faeces/cattle manure alone. The advantage of lactic acid fermentation is the prevention of nutrient loss via leaching, precipitation or volatilization and the relatively short time for faeces treatment: 2-4 months versus 1-2 years of storage (Buzie-Fru, 2010; Factura et al., 2010; Scheinemann & Krüger, 2010) Studies have indicated that the application of lacto-fermented food waste had a positive agricultural effects by increasing the total N, organic matter content, potassium and phosphorous as well as soil moisture content (Lopez Zavala et al., 2002). Addition of charcoal increases the stability of the end product and its potential fertilizing value (Verheijen et al., 2010); the concept on which terra preta soils were based. The long term fertility of terra preta soils was attributed to nutrient holding capacity of added charcoal component (Smith, 1980). However, studies have confirmed that charcoal is not the single factor contributing to the soil fertility (Bottcher et al., 2010; Fischer & Glaser, 2012). For example, several beneficial effects such as increased nutrients use efficiencies, higher and long-term C sequestration as well as more intense humification were observed when combined charcoal and organic matter (Dias et al., 2010; Fischer & Glaser, 2012) were used rather than compost and charcoal alone.