We use the compost tea as hydroponic nutrient solution. our farm is about 70% hydroponic and 30% soil. We only give the compost tea to the soil a few times/year. We use a different formula for the soil, and I’m not going to share the formula because it’s not working well….in short I’m sure weekly application of properly formulated compost tea can work in the soil, but we have not figured that out yet. If someone says that it will interfere with nitrogen or anything else in the soil, it’s just because their formula is not good for the context. My home garden has been running for 5 years completely on worm tea from a watering can. It works. We have not been able to scale this yet.

Our formula works really well for commercial hydroponics (we call it vermiponics)…we almost never have pest or disease pressure when we hit our nutrient solution targets. We only get cabbage butterflies in warm weather and we just got our first sap analysis results that showed high nitrate levels, so I’m thinking we’ll get the cabbage butterfly under control soon enough.

I think compost teas as the primary source of nutrition for soil crops is possible and in rare circumstances ideal. I would not recommend frequent high nutrient (EC>2000 uS/cm) compost tea applications in soil. Low nutrient (EC<500 uS/cm) compost teas that are formulated to be biological inoculants, if done correctly should never hurt the soil. They will either do nothing, or something positive. (they should only maintain the level of biodiversity or increase it).

High nutrient compost teas are something I give highest recommendation for in hydroponics. The difference is that it’s relatively easy to do daily nutrient test on hydroponic solutions. If you can meet these criteria, then it could work for soil:

1)you can afford to do sap analysis

2)you have the expertise to formulate compost teas to address nutrient deficiencies in the sap analysis

3)you have an efficient way to dispense biological (high solids) nutrient solutions to your crop. (drippers can’t do this)

4) #3 method is more efficient than foliar spraying in your context

Our farm is set up for this, but I don’t know any other farm that is. We setup our farm for this because we are high density, and high turnaround (seedlings are planted on the same day the prior crop is harvested). It’s even difficult for a wheelbarrow to move through the farm.