The water requirements for Egyptian cotton cultivation.

This estimation first shows from the current statistics that the cotton yield is not dependent on the amount of water allowed, according to the data presented in the following table.

This leads to the conclusion that the minimum amount of water for the critical period of cotton cultivation is sufficient. Cotton cultivation consumes five-sixths of the irrigation water in the Delta, more than half in Upper Egypt, and three-quarters in both regions combined. Therefore, cotton is the most important crop, and the only one for which we have available statistics. If the cotton yield is the most important indicator of water sufficiency, and it is the only numerical indicator we can obtain.

Given that the yield is not dependent on the irrigation situation in the manner explained above, three years were chosen to perform the necessary calculations. The final estimation of the required water quantity was based on the actual quantities used in these three years.

The average water allowed does not exceed the minimum amount by much.

Other quantities were added to the allowed water quantities to expand the area planted with rice.

In 1908-1909, the area planted with cotton in Middle Egypt increased to its average in the two previous years. The ratio between cotton yield and the amount of water allowed.

During these years, the cotton yield was compared with the amount of water allowed. The comparison is shown in the following table.

Table showing the ratio between cotton yield and water allowed.

Minor errors in the statistics used do not affect the general conclusions presented in the table.