Optimising nutrition in organic tomato production

Summary

The abstract describes experiments with different cropping systems for organic greenhouse production of tomatoes. In this experiment two main questions are adressed. As greenhouse tomato production is a very intensive monoculture production, problems with nutrient supply and balances are expected, and problems with soilborne pests and diseases are widespread. To counter such problems, we compare the normal method of soil grown tomatoes with systems where tomatoes are grown in compost filled boxes. This allows to control nutrient losses and prevent carry over of diseses and pests in the soil. We also study an intermediate system, where where tomatoes are established in compost filled boxes, but the roots are allowed to develop also in the soil outside the boxes. This system seems to combine the main advantages of growing either directly in the soil or in the closed boxes. The other main question is whether the high nutrient demand by the tomatoe crops can be met by plant based materials, rather than by animal manure. The results suggest that suggest that all or at least most of the nutrient supply can be based on plant residues.