Why would it be impossible to engage in agriculture without the creation of an irrigation system?

An irrigation system is a tool that helps people irrigate the vegetation in their fields. Farming in many areas cannot exist without an irrigation system. The reason for this is the unstable position of the weather. Typically, in arid areas, nearby rivers help farmers maintain proper moisture. They run special streams from shore to field, which feed the vegetation during the dry season. Without artificial intervention, the plants would not bear fruit, they could not survive at all.