What percentage of earth's land is arable, or suitable for producing crops?

The correct answer is ten percent (10%).

The Earth's land area is composed of twenty-nine percent only, yet the only arable land for producing crops is equivalent to 10 percent, since in the given 29 percent it also include landforms such as mountains and deserts. Another problem is because of industrialization, wherein infrastructures take lands that are suited for planting and use them for commercial uses.