<span>Their progress and wealth is highly dependent on the harvests, and
the price of grain. They probably have to import some industrial
products and if they had a bad year (weather, other catastrophies, poor
technology) they can't get the necessary amount of industrial products
in exchange for their surplus e. g. in grain. </span>
This statement is true. Soil color only reflects the amount of organic matter that is currently present in the soil. If the soil seemed to be much darker, it means that the soil has a greater amount of organic materials which makes it better.
A I think this is the answer
