Background The excessive application of mineral fertilisers and pesticides results in the degradation of soils. Agriculture intensification also causes an overall decrease in soil fertility. It has been estimated for example, that because of agricultural intensification, the fertility of soils is being reduced by 2.5%/yr. The intensive cultivation of crops often use ‘soil-less’ methods, which call for higher doses of fertilisers than in-field production. For example, in greenhouse tomato production the dosage of nitrogen fertilisers can be as high as 3 000 kg N/ha; whereas the in-field production usage is around 150 kg N/ha. After the production cycle, the subsoils have to be used and are often disposed of in an inappropriate way. This poses a significant pollution risk for the soils, groundwaters and natural environment. In the EU, nearly 500 000 m3/yr of subsoil is disposed of in landfill sites. Therefore, the reduction of the amount of subsoil disposed of in this way is an important environmental protection priority. Objectives The main goal of the BIOREWIT project is to develop innovative technologies for new soil improvers and soil-less substrates for greenhouse cultivation, applied in comprehensive agricultural research. This will include: The use of natural fibrous wastes (e.g. straw, sawdust, wool, cotton) for the production of soil improvers; The use of natural fibrous wastes for the production of biodegradable soil-less substrates; and The application of new fibrous soil bio-activators in the cultivation of vegetables on demonstration plots and on experimental fields for cultivation. Research on soil-less cultivation of tomato and cucumbers will also be carried out on new fibrous substrates in greenhouses and plastic tunnels at RIVC. Expected results: A reduction of the pollution of the soil and water systems through gradual replacement of mineral fertilisers with new soil eco-activators – the target is at least a 20% decrease in mineral nutrient emissions from greenhouse production to groundwater; An overall gradual elimination of mineral nutrient emissions from drain waters of soil-less cultures. (In Poland, the amount of recovered nutrients from greenhouse drainage waters amounts to 120 000 tonnes/yr year (i.e. an area of 60 000 ha). An associated significant decrease of eutrophication of ground and lake water is expected; A gradual process of enrichment of the soil in the organic material through the application of plant biodegradable matter included in the eco-activators – the target is to increase the humus content at least four times more than by mineral fertilisation; A reduction of non-biodegradable bulk waste on landfill sites; A target increase of soil water retention capacity by up to 30% and of drying up time of the soil by 100% as a resulted of the application of eco-activators to the soil environment; and An improvement in the quality of farm products by avoiding the risk of over fertilising some crops with nitrogen.