Vegetable seedling tray seedling cultivation - substrate selection

(1) At present, the substrates commonly used for plug seedling cultivation include peat, vermiculite, perlite, mushroom residue, humus, treated wine troughs, and sawdust.
(2) Grass charcoal is divided into water fresh grass charcoal and gray fresh grass charcoal. Water fresh grass charcoal has a pH of 3-4, a nitrogen content of 0.6-1.4%, and poor hydrophilicity, while gray fresh grass charcoal has a pH of 5-5.5, high nutrient content, and good hydrophilicity.
(3) Vermiculite has a light specific gravity, good air permeability, and strong water retention capacity. At the same time, its potassium content is also quite high, and it has a high salt base substitution capacity.
(4) The pH of perlite is 7-7.5, and it does not have water retention capacity or salt base substitution capacity. In the process of vegetable seedling cultivation, the amount used is relatively small, usually only about 10%. If it is summer, perlite is generally not added.
(5) At present, most domestic plug seedlings are prepared using a ratio of grass charcoal: vermiculite=2:1, or grass charcoal: vermiculite=3:1, or grass charcoal: vermiculite: perlite=3:1:1 by volume.