An ecological technology of coastal saline soil amelioration

Abstract A field experiment was carried out in the coastal region of eastern China to determine an economic and environmentally friendly approach to saline soil bioremediation. The effects of inoculation with an arbuscular mycorrhizal fungus (AMF), Glomus mosseae , and a phosphate-solubilizing fungus Mortierella sp. on the physico-chemical and biological characteristics of coastal saline soil in the rhizospheres of castor bean ( Ricinus communis L.) were assessed during the two-year growing season. Co-inoculation with G. mosseae and Mortierella sp. enhanced the survival percentage and growth of castor bean. AMF colonization in July and September, bacterial population in September, and actinomyces population in July were also improved by microbe inoculation. Soil electrical conductivity values and Na concentrations after microbe inoculation were significantly lower than those in non-inoculation treatments in July and September. P and organic matter content in the soil were significantly enhanced by microbe inoculation during the entire growing season. However, hydrolyzable N content increased only in June and July. No significant differences in soil pH were observed in the inoculation and non-inoculation treatments. Inoculation induced significantly stimulating effects on alkaline phosphatase and catalase activities in July as well as on urease activity in July and August. Invertase activity was stimulated in the entire growing period, except in July. The results indicate that castor bean inoculated with fungi may enlarge the C pool of the coastal saline soil.