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
