V.0x relationship between plants and soil than we currently give it credit for in our simplified understanding of agricultural nutrient demand, which we often reduce to NPK values. Ideally, our agricultural production systems can be designed to take advantage of the inherent complexity of soil communities and their interactions with plants. Another benefit of using soil as a primary substrate is that there is no synthetic waste stream associated with soil-based crop production. Rockwool, the most common substrate for Dutch hydroponic production, needs to be regularly disposed of and re-purchased, presenting both an unusable waste stream and an additional cost. It also poses safety hazards in handling, which are avoided with soil or the use of other kinds of hydroponic substrates. There is a great deal of evidence that the pest infestation problems in current biological soil greenhouses may be largely the result of monoculture cultivation and lack of appropriate rotation schedules. Several studies have investigated the impact of appropriate crop rotations on pest control, to impressive effect. Other studies on the impact of using certain aromatic plants to fumigate soil and repel aerial pests have shown that these approaches are remarkably effective. Up to an 85% reduction in pest-related crop damage was found in some studies that intercropped selected herbs with target crops. On a more philosophical level, there is the idea that whenever possible, we have an obligation to enrich and build soil. Worldwide, high-quality 32 soil is a resource that is quickly being depleted through erosion, salinification, and contamination. Soil can be replenished and improved through careful, productive management. This is something the Polydome system can contribute to, on however small a scale. In addition to the primary soil zone, substrate is also required for the germination and hydroponic production zones. We have chosen to supplement the greenhouse with a hydroponic module in order to increase its overall productivity, beneficially re-use the wastewater effluent from the fish aquaponic module as a source of nutrients, and take advantage of unique vertical stacking opportunities. For the germination zone, we recommend using coir (coconut fiber) as a medium, topped with expanded clay pellets and perlite. Coir is also suitable for the NFT (nutrient film technique) hydroponic channels, though it will likely need to be fixed in some kind of solid, floating framework for the channel system to work. This will also be necessary to prevent the plants from tipping once they get large. An advantage of coir over Rockwool is that it can be reused as mulch or composted, and that it is a renewable material. Pagina 31
Pagina 33Voor brochures, online PDF-en en vaktijdschriften zie het Online Touch content management beheersysteem systeem. Met de mogelijkheid voor een online winkel in uw reclamefolders.
473 Lees publicatie 163Home