Some Helpful Facts about Salinity

I pulled the following facts from Knott's Vegetable Handbook.

UNITS OF MEASUREMENT: The following gives a helpful perspective when reading salinity literature that talks about ppm and millimohs per cm (sometimes written mmho / cm). 1 ppm (part per million) = 1 gram in 1,000 liters of water; ppm x 1,000 = 1%; 1,000 micromhos per cm (a unit of measure for electrical conductivity) = approximately 700 ppm; 1,000 micromohs per cm means that one ton of salt would be in the water that would cover one acre of land to a depth of 1 foot.

The handbook lists several vegetables and the mmho/cm in the soil that reduce yields by 25%. Beet (10), spinach (7), tomato and broccoli (6), cabbage, cucumber, muskmelon, potato, corn and sweet potato (4), lettuce, pepper, radish, onion and carrot (3), bean (2). So beets would be the best vegetable for saline soils, beans the worst.

Some general rules listed for likely crop response to salinity follow. 0-2 mmho/cm, mostly negligible; 2-4, yields of very sensitive crops may be restricted; 4-8, yields of many crops restricted; 8-16, only tolerant crops yield satisfactorily; above 16 only a few very tolerant crops yield satisfactorily.