>>430332That's variable based on the fertility of the soil to begin with. There are ways to increase it, but the composition of the soil also plays a large role in growing healthy crops.
This is one of the reasons hydroponics produces such lush and healthy plants. The water from the fish tank is circulated through the plant beds, which aids in the fertilization process. The water is then recycled back into the tank, which benefits the fish. (Pic Related)
It also helps to rotate your harvest every year. This can help prevent diseases or other things that might be harmful to the crop. So if I planted corn one year, I wouldn't plant the same the following year.
I recommend opening the catalog and looking through the homegrow men thread. They have a lot of useful material on this kind of thing and would be able to help a lot more than I can.
