Crop salinity tolerance and yield function
Salinity effect on plant growth and yield
Salinity reduces water availability for plant use. High salt levels hinder water absorption, inducing physiological drought in the plant. The soil may contain adequate water, but plant roots are unable to absorb the water due to unfavorable osmotic pressure. This is referred to as the osmotic or water-deficit effect of salinity (Osmotic potential = - EC x 0.4). Plants are generally most sensitive to salinity during germination and early growth.
The relative yield (RY) of a crop is related to EC of soil saturated extract (ECe) by:
RY (%) = 100 - Slope * [ECe - ECe (Threshold value)]
Relative salt (electrical conductivity of saturated soil extract, ECe in dS/m) tolerance of various crops at emergence and during growth to maturity (after Maas, 1986).
Salt (electrical conductivity of saturated soil extract, ECe in dS/m) tolerance of herbaceous crops (adapted from Maas, 1986).
1 These data serve only as a guideline to relative tolerances among crops. Absolute tolerances vary, depending upon climate, soil conditions and cultural practices.
2 T = Tolerant, MT = Moderately Tolerant, MS = Moderately Sensitive and S = Sensitive. Ratings with an * are estimates.
Salt (electrical conductivity of saturated soil extract, ECe in dS/m) tolerance of woody crops adapted from Maas, 1986).
1 In gypsiferous soils, plants will tolerate ECes about 2 dS/m higher than indicated. 2 T = Tolerant, MT = Moderately Tolerant, MS = Moderately Sensitive and S = Sensitive. Ratings with an * are estimates.