Answer:
Because they don't have fertilizer.
Explanation:
Well, if this was a long time ago, then farmers did not have fertilizer. So, there are bacteria on the roots of plants that convert nitrogen into a usable form. It's very important for growing, and when farmers harvest the crop, not much of the nitrogen is returned to the land, so it is not as fertile. Fertilizer is largely consisted of nitrogen, so that is why farmers use fertilizers today. But "a long time ago," farmers did not have fertilizer.
Answer: Located within the thermosphere, the ionosphere is made of electrically charged gas particles (ionized). The ionosphere extends from 37 to 190 miles (60-300 km) above the earth's surface. It is divided into three regions or layers; the F-Region, E-Layer, and D-Layer.
Explanation:
Although earthquakes often occur before a volcanic eruption, they are not the cause. The earthquakes are the result of magma (molten rock) moving underground leading up to an eruption. A few volcanic eruptions are thought to have been triggered or initiated by earthquakes, but this is not the typical case.
D) relieving fishing pressure on over fished species