A 100% tax on land would reduce the market value of land to zero.

“Second, if a pure land tax were to capture all current and future rent from the landowners, the market value of the land would become zero. This would be equivalent to the government taking the land from landowners. Thus, people would have no incentive to hold land, leading to abandonment of the land, and likely resulting in governmental decisions about how the land should be used and by whom. Third, the change to a pure land tax would likely have significant redistributional effects, with large landowners likely incurring substantial adverse wealth effects. This effect, however, might be viewed by some as a virtue rather than a fault.”