or neutron type, as has been said why make huge un usable areas, unless you are an alien that thrives in radiation....
Neutron bombs specifically DO NOT contaminate the land. Even less so than conventional bombs.
That is their advantage. Neutron radiation is very deadly but just passes through objects and then is gone. They also cause a much smaller explosion that conventional nuclear bombs, allowing the enemy to 'cleanly' kill a city and leave it relatively undamaged.
All nuclear bombs produce a neutron pulse, but normally that pulse is smaller than the physical destruction area of the bomb so is irrelevant.
There is a type of bomb designed to render area's uninhabitable (temporarily) This is called 'Salted Bomb', as it includes large amounts of sodium isotope and would 'salt the earth'. by make a large area dangerously radioactive for a few years, or powerful enough to virtually sterilize a large area (hundreds of miles across)...but the effects would be gone within a few days.
An important rule of radiation weapons is that the duration of the radiation, is directly inverse to the time it remains radioactive. The most dangerous fallout decays IN SECONDS. While some lasts for thousands of years, it is so mildly radioactive it's not dangerous.
These 'Salted Bombs' are pretty scary. None are known to have been made but that is of limited comfort.
What is helpful is that a logical enemy, would not use them as war for the simple sake of destruction is rare.
Far more likely is a limited nuclear war where nuclear bombs are used to destroy conventional targets like military basis, productive cities, etc.
