Analytical methods used in soilless cultivation

摘要: Laboratory tests, which give a reliable indication of the performance medium with respect to water, nutrient, and oxygen availabilities on short long term, are normally more cost-effective, can be performed under standardized conditions reference samples. It is therefore logical that analytical methods, mostly adopted from soil science have become available as part selection process growing media for setting soilless standards. Such analyses physical, chemical, or biological. Methods physical analysis include determination bulk density, porosity, measurement particle size, water retention air content, defining rewetting curve, rehydration rate hydrophobicity, measuring shrinkage, saturated hydraulic conductivity, unsaturated diffusion, penetrability, determining hardness stickiness. The chemical determines water-soluble elements (1:1.5 volume method, 1:3 substrate solution 1:5 pour through method), exchangeable, semi- non-water soluble (calcium chloride/DTPA 0.1 M barium chloride 1:1.5 active manganese pH in loose media, nitrogen immobilization, calcium carbonate content. Finally, biological stability, potential biodegradability, heat evolution, respiration by consumption. employs solvita test, weed growth test.