We have read that vegetable gardening requires rotation -- not planting the
same crop (or crops in the same family) in the same spot multiple years in
succession. It often seems to be recommended that as many as two years pass
by before replanting the same crop in a particular spot. Apparently each
crop type attracts pests of a particular type, which then damage the crop if
it is planted in the same spot the next year.

We have a situation where we can have only a very small vegetable growing
area, which has to be reused year after year. For us, rotation would
require growing a totally different vegetable each year. However, we prefer
to grow mainly tomatoes, and would like to grow tomatoes each year.

Is there anything we can do to "recondition" the soil to eliminate the need
for rotation?