EFFECTS OF SUB-SOILING AND FERTILIZATION ON GROWTH RESTORATION OF PHRAGMITES AUSTRALIS POPULATION IN SALINE MARSH OF NORTHEAST CHINA

摘要

Inland salt marshes are widely spread in western Songnen Plain of Northeast China. Lacking of water resource was the main factor driving degradation of this inland saline marsh in the past decades, with the degeneration of the dominated plants, Phragmites auatralis production. Sub-soiling and fertilization are two kinds of agricultural technology, which are developed and used in agriculture to gain high production. Field mesocosm experiments were conducted in western Songnen Plain by using two distance sub-soiling and four different kinds of fertilizer, to restore the P. australis production and avoid the further degradation of saline marsh. After these technologies were used, the growth and production of P. australis were improved effectively. The height, stem diameter, heading number, ear length and biomass were increased significantly, although the plant density was not influenced by fertilizer. The increment was more for sub-soiling than for fertilizer. From the comparative results, we concluded that hardening in saline-alkaline soil was the key factor affecting plants growth rather than nutrition, and chemical fertilizer urea was more effective than others. Although these agricultural technology could be effective to restore the population growth of P. australis, water resource was still the key structure and environmental factor in marsh restoration.