When turnips are clover were, planted the soil was replenished. So rather than letting a field lay follow, farmers could periodically replace wheat ans barley crops with turnips and clover.
It worked by gowing a root plant in the field that would be fallow which would release nitrogen into the gound
Crop rotation refers to the practice of seeding fields with different crops each year and allowing the field to sometime lie fallow.
Charles Townshed introduced the Norfolk crop rotation.
The fallow field was allowed to grow whatever grew there, and was often used for grazing. Legumes were grown in the other fields, but in the Middle Ages, they did not have New World beans, and legumes were mostly peas and fava beans.
Fallow means an area which isn't used for growing crops. It could be an area which is wild and has never been used or one which is given a cycle of "rest" as part of crop rotation.
During the middle ages a system of crop rotation was developed in which a field was used to plant one crop on year, another crop the next, and lay fallow the third year. This system allowed two thirds of the land to be in use for crops at any time. The previous system was a two crop system that only allowed half the fields to be in use for crops.
Crop rotation.
The Norfolk system, was a new system in which four crops were rotated instead of three. This system also removed the fallow field and replaced it with turnips and clover. These made excellent winter cattle feed as well as enriched the soil with nitrogen which was found to exist on the tips of their roots. When the plant was removed, the root tips and nitrogen was left behind. This system greatly increased profits as it removed and enriched the fallow field.
In Pullman, WA, it is not a requirement for farms to remain fallow during a specific period of time. Farmers in the area typically follow crop rotation practices and soil management techniques to maintain soil fertility and health. The decision to leave fields fallow would depend on individual farming practices and goals.
Leaving fields unplanted allowed soil to recover from cash crops production, but it was impossible for poor farmers who needed the money from the sale of their crops.
You are asking in a strangely awkward way about crop rotation. In crop rotation, every field was left uncultivated, or fallow, every few years in order to replenish its nutrients.
Crop rotation helps save the soil. Sometimes we let the field go fallow for a season.