Complicated licenses, royal monopolies, etc. But during the turmoil, it couldn't enforce them, which made for freer markets. Another factor was a remarkable increase in agricultural productivity in the 16th century. As food prices started to rise, it became profitable for farmers, both large and small, to invest in agricultural technologies that would improve crop yields. Those higher prices for grain probably resulted from population growth, which in turn was encouraged by increased production of food crops. A number of these agricultural improvements came from the Dutch, who had chronic problems feeding themselves, and discovered that planting different kinds of crops, like clover, that added nitrogen to the soil and could be used to feed livestock at the same time, meant that more fields could be used at once. This increased productivity eventually brought down prices, and this encouraged further innovation in order to increase yield to make up for the drop in prices.