Answer:
Random environmental factors can make the whole harvest to fail
Explanation:
For a certain type of crops to be successful, farmers need the combination of suitable environment, proper care, and enough nutrients.
From those 3 factors, Environment always considered to be uncontorralble. ( such as rain, temperature, or windy season)
If we invested all the resources on one single crop, random events of unfavorable environment can destroy all the source of income. This practice has a lot of risk compared to diversifying the crops into several types. Even if one type of crops fail, the income from the other types of crops might be enough to cover the loss.