Soil Salinization and Countermeasures in Protected Horticulture

Soil salt contents of protected horticulture in Shandong Province were analyzed. The result indicated that the increase of fertilization applied caused the soil salinization ,the salt content in inner greenhouse was 1.34～3.74 times that in outer side, the salt peak was formatted in protected horticulture aging 3～5 years whose mean electric conductivity was 1.21 ms/cm, and the largest one was 4.06 ms/cm; contents of salt ions were also increased to different degree, contents of K⁺、Ca²⁺、SO^2-₄ and NO^-₃ could be 2.1～21.5 times of that outside, and could increase more than others. The soil salinizing reasons of greenhouse were analyzed in this article, and the sustainable development measures were put forward.