Salinized drinking water probably is the best insurance that the men will take the salt during the working hours of the day. A study from the Inland Steel Company⁵⁶, in which a section of steel workers, 3,000 men, were given salinized drinking water, 0·1 per cent., showed good results as compared with the control group.
Soil erosion is only one of many serious threats to farmland. Much of the twentieth century’s gains in crop production was due to irrigation. But irrigation can also salinize soils. Because most irrigation occurs in parched regions, the abundant sunlight of dry climates evaporates much of the water away, leaving salts behind.