Developing organic tomato production in the participatory research context

The roles of different actors in agricultural knowledge and innovation systems are currently converging and thus participatory approaches are becoming increasingly prevalent. These new platforms offer scientists and farmers a space for dialogue, where desirable and feasible solutions to common problems can be identified, analysed and implemented. A successful initiative in this context in Sweden is the project 'Plant nutrient utilisation in organic tomato production', which was carried out by a participatory research group that worked together in the period 1999-2010 on issues concerning organic tomato growing. The group included commercial tomato growers, advisors and researchers. When the plant nutrition project started, knowledge of plant nutrient supply in organic tomato growing was limited. It was common for most of the nutrient requirements of the crop to be supplied as large doses of farmyard manure before planting, which created problems with leafy plants in the beginning of the season and nutrient deficiencies. The aim of the project was to develop organic tomato growing, for example through demonstrating the importance of tailoring fertiliser supply to crop requirements at a particular stage of growth, level of yield and local conditions. During the period in which the project ran, the yield of tomatoes in the group's cultures increased by 49% on average and the nutrient use efficiency was improved substantially for the major nutrient elements. Among other projects within the frame of the project the effect on pH of additives and, heavy metals in soil and plants are presented.