Irrigating the deserts

[Romeo]

Why don't we irrigate deserts like the Sahara or the Australian and grow forests and crops there for our needs?

[fairkatrina]

Mainly because the money and international co-operation required for such a feat are near impossible to get.

Australia isn't really a viable option anyway since some bloke back in the 1800s decided he missed rabbit stew, imported 24 pairs and the population decimated the plants, which led to the exposed topsoil being blown/washed away. Therefore the soil is probably too infertile to support large, sustainable crop growth, even with irrigation.

As for most of the planet's other desert areas, they tend to be in places where the human population don't even have basic irrigation for drinking water etc, and that is considered a higher priority than irrigating the land for crops.

[Loosehead]

Ok so clearly you've given up on the Mars idea! Unfortunatley although it's a lot easier to irrigate the deserts than to terraform Mars, it's still impossible without a global effort and as we are still fighting over which mythical being to believe in, I guess that's unlikeley!

[heathfield]

Infertile soil apart, one of the problems with irrigation in hot and sunny climates is that the water rapidly dries out on the surface, leaving behind all the minerals that were dissolved in the water. This leads to the soil becoming salty.
This is currently a problem for citrus growers in South Africa and the Middle East

[joko]

because most of it is sand... and plants don't grow in sand