To understand the output of agricultural crops that depend on natural conditions. If seasonal rains have produced a price slump last year, look no further than no rain? Disaster is an excellent little output on industrial products, which can be controlled to produce at any time.
To understand that agricultural productivity depends on nature. The seasonal rains are falling in price to yield any meteorological conditions. Disaster will yield less well against products which can be produced at any time.
To understand that the crop agriculture depends on the state of nature. If the rain season will be produced, the price will be low. Any year rain no director disaster, yield little, the price will be good.