Underlag för jordfri odling med kontrollerad vattenhalt i tjockleksrik tningen

摘要

The invention relates to novel substrates for soilless culture. …The substrates are formed by a felt of mineral fibres which present a water retention gradient in such a way that the water retention decreases in the direction of gravity. …Substrate I presents a water retention gradient due to a gradient in fibre fineness in such a way that the mean diameter of the fibres increases in the direction of gravity. In substrate II, the diameter of the fibres varies in the opposite direction. Water retention is higher in substrate I than in substrate II. ……