How did italy's land allow it to support a large population

Italy's land allow it to support a large population because of their management in terms of housing. Since Italy knows that their land area is limited, then this led to newer solutions provided by the people and the government. Take for example, Venice. This is one of the most beautiful cities of the world, and it is composed of houses floating in canals and are linked by bridges. This kind of infrastructure has helped Italy support its large population.

Italy has a vast access to the sea which means three things:
1) additional food source (sea food, including fish)
2) trading opportunities (trading typically happens over water)
3) mild yet warm climate which is good for growing crops

All those things together made Italy a Rich country and allowed for a huge population to have access to resources.

The answer is crop yield.