Question

Soil salinization is a major agricultural problem. It is caused by a buildup of salts in the soil, either from salt-bearing rocks or from irrigation. (Trrigation with water containing salts graduallymatd salts, since the water evaporates but leaves the salts behind.) Here in North America, it is esti that about sixteen million acres of land are affected by soil salinization. Explain, using the co water potential, why soil salinizati 6. builds up mated on reduces crop yields or even completely kills crop plants. ncept o slide lood,

Answer 1

Water potential of pure water is the highest (= 0).

Water potential of any solution is negative. Water moves by bulk movement or passive diffusion in plants. If water has to move from soil to root cells, the soil water potential must be lower than the cytoplasmic contents of root cells. If the salinity of water is very high, the water potential of soil water becomes very less. This leads to exosmosis of water present in the root cells instead of water absorption. Hence, high salinity can reduce plant fitness and there by crop yield. Very high salt concentration can even kill root cells by exosmosis.