Effects of Salinity on Plant Growth and Crop Yields

Abstract

All plants can be killed by salt solutions if the concentration is high enough. The ability to survive at a particular salinity is important ecologically in influencing the natural distribution of plant species in salt-affected soils. Survival may also be of importance in agriculture, if the salinity of a field is such that individuals of a particular crop die, although most agricultural interests (and most research) deals with the effects of sub-lethal salinities. Generally, the effect of salinity (and here we are concerned primarily with NaCl as these ions are the commonest cause of salinity) on plants have been determined not in terms of survival, but in its effect on vegetative growth. Growth clearly is a key parameter in both ecological and agricultural contexts. However, in both cases a third parameter, seed production, is also critical, although for different reasons. In ecological terms seed production may be a survival mechanism, whereas in an agricultural context, it is commonly the seed which is harvested. Therefore, there are three parameters which might be used to assess the effect of salt on a particular species — survival, vegetative growth and seed production. All are, of course interlinked as there can be no yield without survival, although a species may survive vegetatively and yet fail to produce seed.