Maintaining soil health for crop production in organic greenhouses

- Intensive organic greenhouse production can lead to soilborne diseases.
- Soil steaming creates a “biological vacuum” resulting in re-invasion.
- Solarization and anaerobic disinfestation eliminate pathogens without re-invasion.
- Soil health and disease suppression can be promoted by appropriate amendments.

Organic production in intensive greenhouse operations, while maintaining soil health and sustainability, is a challenging task. Organic greenhouse crops must be rotated, but the rotations are short, so that rapid buildup of pest and pathogen populations can occur to levels causing significant damage. Heavy soil infestations together with the need to maintain profitable production forces the farmer to use effective control measures, while trying to maintain soil health and quality. If resistant cultivars or cultivars grafted on resistant rootstocks are not available, some form of soil disinfestation may be needed to eliminate the majority of root pathogens and pests in the soil. Soil steaming creates a “biological vacuum” that is prone to re-invasion by pathogens and pests. Selecting a soil treatment that preserves the biological equilibrium in soil, enhances the development of natural disease suppressiveness and provides an increased growth response is preferred. This is especially important for intensive organic greenhouse production, where a healthy soil is a prerequisite for the profitable production of healthy crops. Soil health can be promoted by aerobic soil disinfestation (“biofumigation”), anaerobic soil disinfestation, solarization, and a combination of these treatments. Here, we present a variety of strategies and approaches for the promotion of soil health and disease suppression in organic greenhouses.