Can Mars top soil be transformed to be arable, and how to do it?
It may be planted in the isolated space.
The problems of the Mars are these:
It is cold. Practically no plant can survive below 0 degree. On the Mars, only on the equatorial noons do we have $\approx 15 ^\circ C$. The problem can be solved by glass houses.
There is no oxygen. While plants create oxygen by photosynthesis, they also use them. They don't need too much.
There is only very little water. Although many water was found recently there, overall the Mars is still so dry, like the Sahara. It is possible, that water ice should be regularly mined on the poles, and then it has to be taken to the equatorial glass houses.
Significant radiation from the Sun, mainly UV. It is because Mars has no ozone layer (to defend us from the UV), and only a very little magnetic field (to defend us from the protons). Note, a single layer of glass, what we have also in the windows, filters out practically all the UV.
Perchlorate salts in the soil. They are poisoning for most plants, but making the resistant is not impossible with genetic engineering. There are known perchlorate-resistant bacteria. Alternatively, the perchlorate ions could be removed from the soil by chemical means.
These all can be solved, but none of them is easy.
Most likely, the first plantations will be in glass houses and they will utilize mined water, and use processed soil. They will need to operate in closed water and athmosphere loop.