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?
It is necessary to mix JWA with water dissolved in Sodium Hydroxide and spray it. At this time, soft water should be used. It works very effectively against slugs. Continuous use of Sodium Hydroxide can adversely affect soil microbes, but there is no other way to control slugs.