how is 10-10-20 used on potatoes and veg garden in general (before or after planting, is there a need to turn over soil after spreading) and is the procedure repeated during the growing season.
It is applied as base fertilizer after the ground have been dug over and before final cultivation before sowing. It can be applied at about 50g per square metres for most uses and 100g per square metre for potatoes and vegetables.
It can be used at lesser amounts if farmyard manure or mushroom compost is applied in sufficient quantity, or if the soil is already quite fertile.
It is applied before each season and brings up the general fertility of the soil for the rest of the year.