3. Why is relying on a short list of major food crops a concern?

Relying on a short list of major food crops is a concern.

Explanation:

Different food crops require different types of soil. Thus all kinds of food crops cannot be cultivated in the soil of a country. In addition to that the amount of land available for cultivation is limited by growing settlements and industries.

Thus growing reliance on limited number of food crops is a serious issue. When all the people start depending on a few type of major food crops the production from agriculture won't be able to feed all the population. The increase in demand for major food crops will result in the increase in their prices.

This would mean that only the wealthy would be able to afford them. This will eventually lead to poverty and decline in economic growth.