Re: Yellow River: Facts on File

[Yoshie Furuhashi <furuhashi.1@xxxxxxx>]

> Michael Perelman:
> >  I don't understand how it would lead to salinization, but the E. Asian ag.
> >  system was remarkably sustainable.  Silting seems to be more related to
> >  removing the forest cover.
>
> > > What Happens when you Irrigate?
> Irrigation inevitably leads to the salinization of soils and waters. In the
> United States yield reductions due to salinity occur on an estimated 30% of
> all irrigated land. World wide, crop production is limited by the effects of
> salinity on about 50% of the irrigated land area. In many countries
> irrigated agriculture has caused environmental disturbances such as
> waterlogging, salinization, and depletion and pollution of water supplies.
> Concern is mounting about the sustainability of irrigated agriculture. <<
>
> from:
>
> http://www.ussl.ars.usda.gov/salinity.htm
>
> Mark Jones

From the website mentioned above:

*****   Why do we Irrigate?
Irrigation is an ancient and important agricultural practice. Crop
yields are higher under irrigation and less dependent on the effects
of weather. While only 15% of the world's cultivated land is
irrigated, it accounts for 35-40% of the global food harvest....
*****

Yoshie