Selection Of Substrates Of Raising Cucumis Sativus Seedling In Industrial Scale

In order to get the substitute for the vermiculite and peat media , the experiment was conducted to study the effects of compost of three kinds of medium ,sawdust, peat and residue from mushroom culture which were mixed up with different levels of organic or inorganic fertilizer on Cucumis sativus seedling growth .The results showed as follows:1) Decomposition had a great influence on physical and chemical properties of sawdust. After decomposition,the volume weight of sawdust increased , the total porosity decreased , PEL EC of sawdust increased , and CEC increased greatly ,too.2) There was no phenomenon of irregular emergence and yellowing of seedling in this experiment when decomposed sawdust and residue from mushroom culture were used to raise seedlings.Seedlings of all treatments in the experiment had very high emergence ratio. 3) When 5d , seedlings in the substrate of sawdustpeatresidue from mushroom culture=6:3:1, added 20g baked-dry chicken manure, were better.When 13d , seedlings in the substrate of sawdust:peat:residue from mushroom culture=6:2:2 , added 5g urea and 5g KHiSdt, were better ,their many indexes exceeded those of contrast .At the earlier stage (5d-9d) ,photosynthate were mainly used to amplify the leaves and extend stalk ,which caused the disharmony of overground and underground ;at the later stage(9d-13d) ,more photosynthate were distributed to underground,so that roots growed fast. The contrast had similar growing condition. When 17d ,seedlings in the substrate of sawdust: peatresidue from mushroom culture=6:1:3 ,added 5g urea and 5g KH2SO4,and the substrate of sawdust: peatresidue frommushroom culture=6:4 ,added 5g urea and 5g KH2SO4,were best ,their many indexes had gradually exceeded those of contrast ,but there wasn t apparent difference among them .Moreover ,the two substrates mainly consist of sawdust and residue from mushroom culture ,which were organic waste , cheap, abundant and easy to get. Therefore, in the area which lack of peat when Cucumis sativus seedlings were raised in the summer ,the two substrates can substitute for peat.4) In whole growth ,the difference of physical and chemical properties amony substrates caused the difference of seedlings growth condition ,as well as the difference of rapid growth period. 5) Fertilizer , Substrate and their interaction have influences on seedlings growth.But their effects weren t striking in view of the seedlings dry weight (DW) .The sequence of their influence on overground DW was: Fertilizer,Fertilizer*Substrate , Substrate ; while the sequence of influence on underground DW was :Fertilizer* Substrate , Fertilizer , Substrate .In the practice ,the best formulae of substrate and fertilizer should be achieved on the basis of main factor which influences seedling growth.