Hello Mr.Youngsang Cho,
I have located an abundance of slugs that are living deep in the soil (30cm) under my entire crop. I suspect they travel up to the plants and fruit trees every few days, feast and return to the safe area. Sodium Hydroaxide has been used weekely as a foliar spray for many months, and on occasion a light spray at the base of the plants and fruit trees. I am loosing this battle and would like to know if I am able to soak the soil to 30cm using the sodium hydroxide without harming the Microbes?
Maybe you have a different solution?
Your are changing your world. Bless you.