Answer:
D. Fields are left fallow after being farmed intensively so that nutrients in the soil may be replenished.
Step-by-step explanation:
Salinization is the process that promotes the accumulation of Na + and Cl- salts on the soil surface, preventing plants from absorbing important nutrients for their growth and development.
This process happens a lot in arid and semi-arid regions. This is because the amount of rain in these regions is very low, but the evaporation of soil water happens very intensely. Because of this, it is necessary for farmers to establish many irrigation points and as we know the water contains numerous mineral salts.
The amount of irrigation in these soils ends up promoting an accumulation of water in the soil, however as the evaporation is intense, the water evaporates, leaving only its salts in the soil that are accumulating and causing loss of fertility.
In other words, irrigation increases the salt content of the soil, which stops crop growth and decreases soil fertility.