compunded by the soil erosion problem - sure is grimPitch Black wrote:Re: Australia's drought, I really reccommend Jared Diamond's "Collapse" for an overview of the situation.
Basically, Oz's current system of agriculture is doomed, even without climate change, because before the European settlers arrived all the nutirents in the biosphere were locked up in the vegetation, instead of the soil. When the colonists burnt and cleared the land for pasture and crops they permanently removed these nutrients from the biosphere. They're not coming back. Irrigation and such moves water around to certain areas, giving arable land in the short term, but ultimately this breaks down too, because this increases salinity, ultimately making the land unusable.
from wikipedia: "Salinity from irrigation can occur over time wherever irrigation occurs, since almost all water (other than natural rainfall) contains some dissolved salts. When the plants use the water, the salts are left behind in the soil and eventually begin to accumulate. Since soil salinity makes it more difficult for plants to absorb soil moisture, these salts must be leached out of the plant root zone by applying additional water. This, in turn, can lead to rising water tables, requiring drainage to keep the saline groundwater out of the root zone. If the water table rises too high, then natural soil evaporation will begin to draw the salts back upward into the soil profile. The problem is accelerated when too much water is added too quickly due to inefficient water use such as over-irrigation, applying more than is required for leaching, using bad estimates of evapotranspiration and poor system design, and is also greatly increased by poor drainage and use of saline water for irrigating agricultural crops. These practices result in the concentration of salts."
So I'm afraid Oz's system of farming is fucked, even without taking climate change into account.
this another one of those things I've not really looked into, but living in Queensland where it's very green and lush it seems as though the farms are just in the wrong places
equally western Australa is massive and there seems like a lot of unused potential there too - esp. in the northern part
a lot of australia is tropical so you'd think that would count for something
anyway, you kiwis would say that, we'll have to import or vegies from NZ!
