see that could be good or bad...cuz there could be sum good stuff in there , it could be choc full of shit you dont need, try testing the ph level of the runoff after you water next time if you can but normally you should give nutrients after they get a little bit mature... they got all they need already in em for the seedling stage and most soils you buy have 3-4 weeks of fertelizer in em unless you get miracle grow... but thats bad.
so the possibility of that plant having a nutrient deficiency is slim