What was the advantage of canals?

Canals are fed by rain water received by rivers, and the water is used for irrigation. Production of crops needing more water is also possible through canals. As compared to un-irrigated soils, higher productivity per hectare is also possible due to canals. The main advantage to canals is the ease of shipping goods.

they wanted the u.s. to fight on the side of the central powers.

when a country suffers, for example, a drought period, the market product is affected for a low offer, in this case, potatoes; the government has to tax to the households, which have to give more money for the potatoes which they consume, that situation make them consume substitute goods even through loans, it could increase the financial market movement and the inflationary phenomena, the business has to increase salaries in order to the employees could buy a more expensive food (potatoes) and in order to inflation tha business had to buy expensive supplies in the factor market, while the rest of the world have to gain more money to consume the same amount of potatoes.