The question asks us in which of the following circumstances would it be LEAST advantageous to use the methods from the Netherlands study?
The passage tells us that "the quickest way to restore heavily fertilized land is to remove and replace the topsoil.."(Lines 12-14). The Netherlands study focused on alternative methods for cases where removing and replacing topsoil or waiting it out is impractical, therefore, it is least helpful in a case where removing the topsoil is an easy solution.