Abstract: In the present study， several compound nursery substrates composed of vermiculite， slag， fine sand， perlite and peat in different combinations and ratios were selected for raising tomato seedlings in 72hole seedpans. It was shown that the substrate composed of peat， slag and vermiculite at the volume ratio 1∶1∶1 was suitable for tomato seedling growth. The rhizospheric microbial biomass and enzyme activity in tomato seedlings cultured in this substrate was increased compared to those seedlings cultured in control substrate， which was composed of peat and vermiculite at the volume ratio 2∶1. The increase of rhizospheric microorganisms and enzyme activities could promote tomato seedling growth. Consequently， the stem diameter， plant height， dry matter accumulation of seedlings in the above substrate were the biggest among all the tested substrates. In conclusion， the substrate composed of peat， slag and vermiculite at the volume ratio of 1∶1∶1 was beneficial for industrial seedling of tomato.

Key words: tomato, nursery substrates, seedling quality