I have been growing tomatoes in barrels for the past years. I add egg shells, citrus peelings, newspaper, banana peelings,etc to the used soil. I\\\'ve also added leaves and other clippings throughout the year. I don\\\'t really have a compost pile....I just throw these things in the barrels of used soil from the porch. Occasionally I\\\'ll add some slow release fertilizer in. I\\\'d planned on adding garden soil to the whole thing just before planting the tomato plants. I\\\'ll mix all of this together before planting. Will these additions be good enough to reuse soil that\\\'s been used 2-3 years in a row. I have also acquired baby ducks and have added the poop to the compost. Will this make a difference?
Reusing Last Year\\\’s Soil for Vegetables
Certified GKH Gardening Expert
With enough time, it will all break down into a useful soil, with the exception of one thing... The added fertilizer. You will not need to do this. This will make a mix too "hot" for plants to grow. You will want to cut this pretty heavily with potting soil before you reuse this. I would say 1 part of your mix, to 3 parts bagged potting soil. In the future, just hold off on the added fertilizers. The scraps that you are adding are going to become the nutrients.
If you want to add something to help, then I recommend adding mycorrhizae to the soil. This beneficial fungus will help things break down a bit faster.