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Large-scale vermicomposting under outdoor conditions may differ from small-scale procedures in the laboratory. The present study evaluated changes in selected properties of a large-scale vertical-flow windrow vermicomposting system with continuous feeding with household biowaste. The windrow profile was divided into five layers of differing thickness and age after more than 12 months of vermicomposting. The top layer (0-30 cm, age <3 months) was characterised by partially decomposed organic matter with a high pH value and an elevated carbon/nitrogen (C/N) ratio. The earthworm biomass was 15 g kg with a population density of 125 earthworms per kilogram predominantly found in clusters. The greatest amount of fungi (3.5 µg g dw) and bacteria (62 µg g dw) (expressed as phospholipid fatty acid analysis) was found in this layer. Thus, the top layer could be used for an additional cycle of windrow vermicomposting and for the preparation of aqueous extracts to protect plants against diseases. The lower layers (graduated by 30 cm and by 3 months of age) were mature as reflected by the low content of ammonia nitrogen, ratio of ammonia to nitrate nitrogen and dissolved organic carbon, and high ion-exchange capacity and its ratio to carbon. These layers were characterised by elevated values for electrical conductivity, total content of nutrients, available magnesium content, and a relatively large bacterial/fungal ratio. On the basis of the observed properties, the bottom layers were predetermined as effective fertilisers.

The main by-product of wine-making is grape marc. With proper treatment, grape marc may return to the vineyard as a fertiliser. This study deals with the vermicomposting of grape marc in a continuous feeding system in outdoor conditions for more than 12 months. The N-NH4+, dissolved organic carbon (DOC), and N-NH4+/N-NO3- contents were greater in the top layers. The pH value was about 8 in all the layers. The electrical conductivity was the greatest in the bottom layer. The ion-exchange capacity did not modify significantly during vermicomposting. The microbial biomass was the greatest in the upper layer, as well as the number and the biomass of the earthworms. The process of vermicomposting seems to be an ideal way of processing residues from the winemaking industry. This vermicompost has very good properties for use as a fertiliser, and for returning the nutrients and organic matter to the soil, for example, in a vineyard.

Material alternatives to wood, such as rape straw, are needed for the production of composite materials. This study performed an analysis of rape straw as a composite material source for production. There were three types of rape straw particle modification: untreated particles as reference variant, boiling in water, and soaking in sodium hydroxide (NaOH) solution. The pH and calorific value were highest for the variant soaked in NaOH. The total elemental content and the elements on the rape straw surface varied between variants. The modification method chosen influenced the pH, calorific value, elemental composition, and contact angle. Keywords INTRODUCTIONRecently there has been an effort to develop new composite materials using alternative sources of raw materials. This trend is largely explained by population growth, which contributes directly to a limited supply of natural resources, as well as wood shortage in all wood processing industries (Galor and Weil 2000;Bektas et al. 2005;Seintsch 2011;Lauri et al. 2012). One alternative source of raw materials is post-harvest rapeseed crop residue (Mohanty et al. 2002;Dziurka et al. 2015). As a prospective raw material, rapeseed has many advantages, as it is available in large quantities and is not yet used in other products with high added value (Bečka et al. 2007;Dukarska et al. 2017). However, waxy and siliceous substances are present on the surface of winter rape stems, which prevents the formation of quality adhesion between particle and adhesive (Grigoriou 2000). This is the main disadvantage of particles from annual plants compared to wood particles. The chemical composition differs between internal and external areas of the stem because of cuticles and epicuticular waxes (Wiśniewska et al. 2003;Trischler, and Sandberg 2014). The surface has a strong impact on the water contact angle, which deteriorates the wetting of particles by adhesives, since adhesives used in particleboard production are mainly water-based (Wiśniewska et al. 2003). Therefore, it is necessary to pre-treat these particles from annual plants before the production of the composite material itself (Mahlberg et al. 1999;Cao et al. 2017). This modification can PEER-REVIEWED ARTICLE bioresources.com Částková et al. (2018). "Modified rape straw," BioResources 13(1), 104-114. 105 be done in various ways (Pelaez-Samaniego et al. 2013;Trischler and Sandberg 2014). Boiling in water is regarded favorably as a treatment due to its ease of implementation (Bekhta et al. 2013). An alternative is alkaline treatment, which breaks ester linkages between wax and lignocellulose, as well as dissolving wax and lignin (Binod et al. 2010;Wan et al. 2011). In this study, winter rape chips were modified by applying hydrothermal and chemical (soaking in sodium hydroxide) processes (Xie et al. 2010;Bekhta et al. 2013). It is assumed that the modification destroys the waxy, siliceous substances on the surface of the chips and consequently improves adhesion in the composite product. This study characterized the phys...

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