About 20 species of crop plant were examined by means of constant renewed sand culture. Culture solution was prepared adding Na₂SO₄ or NaCl to the basal nutrient solution. The concentration of prepared solution was 20, 40, 60 meq/l respectively. The results are as follows;

1. Though Italian ryegrass, barley, asparagus and spinach revealed similar high salt tolerance, they can be classified into two types in terms of the difference of nutrient uptake; that is, Italian ryegrass, barley type and asparagus, spinach type. The salt tolerance of the latter seemed to be higher than the former.
   　Cucumber and lucerne showed low salt tolerance.
   　Generally, the tolerance against chloride was lower than that against sulfate.
2. As for the mineral elements in the plants of the Italian ryegrass type, the absorption of sodium and the ratio of cation to anion increased in accordance with the increase of the salt concentration of culture solution, and the hindrance on the absorption of potassium, calcium, magnesium and manganese decreased antagonistically.
   　But the decline of yield was not much because the plant of this type was able to endure excessive sodium and the want of potassium and calcium, etc.
   　Cucumber and lucerne revealed also similar phase of nutrient uptake but their endurance against excessive sodium and the want to potassium and calcium, etc. caused by the decrease of the ratio of cation to anion according to the increase of the salt concentration of solution was not strong as that of the Italian ryegrass type. Consequently, the salt tolerance of cucumber and lucerne was not high.
   　The crop plant of the asparagus type seemed to have the controlling function for the absorption of sodium so that hindrance on the absorption of potassium and calcium, etc. was not strong and the ratio of cation to anion did not vary greatly.
3. The salt tolerance of rice plant seemed to be moderate from the viewpoint of the yield, the absorption phase of mineral elements and the ratio of cation to anion.