Distribution characteristics of different salt ions in soil under drip irrigation with saline water

Field experiment was carried out to investigate the distribution characteristic of different salt ions in the soil under drip irrigation with saline water in North China. The experiment included five treatments, in which controlled the mineralization degrees of irrigation water were 1.1 dS/m(K1), 2.2 dS/m(K2), 2.9 dS/m(K3), 3.5 dS/m(K4) and 4.2 dS/m(K5), respectively. The results showed that the transferring velocity and distribution characteristic of salt ions were affected by water distribution in the soil under drip irrigation condition. Ca²⁺, Mg²⁺ and SO^2-₄ were easily leached by irrigation water and distributed mainly outside the moist volume, while HCO^-₃, Na⁺ and Cl^- mainly distributed in the moist volume. During the growing period, HCO^-₃, Na⁺ and Cl^- increased slightly though the total salt content within the soil profile did not increase.