关键词: 稻鸭共作, 人工除草, 化学除草, 物种多样性, 均匀度, 相似性

Abstract: With saline soil and non-saline soil (cotton soil) as test soils, four types of desert halophytes were planted in pots by using horizontal root-mat method. Stratified soil samples at different distance from rhizoplane were collected by slicing the frozen thin soil layer, and their pH value and the contents of total salt, Cl-, SO42-, Na+, K+, Ca2+ and Mg2+ were determined. The results indicated that in saline soils, the pH value at different distance from rhizoplane presented a regular gradient distribution, i.e., the nearer the distance from the rhizoplane, the lower the pH was; while in cotton soil, the pH had no significant variation. There was a relatively great salt-deficit area in rhizosphere, with the highest deficit rate appeared at 0〖KG-*2〗-〖KG-*7〗4 mm from rhizoplane. In saline soil, an enrichment of Cl-, SO42-, Na+, K+ and Mg2+ was observed in the rhizosphere of all test plants except Phragmites communis; and in cotton soil, the ions except K+ also showed a high concentration in rhizosphere, but lower than that in saline soil. Additionally, in cotton soil, K+ was in deficit, while Ca2+ was rich. All test plants, especially succulent halophytes and salt-secreting halophytes, had higher contents of Cl-, Na+, Ca2+ and K+ in their aboveground part than in their underground part. Cl- and Na+ had the highest content in rhizosphere, and showed the largest accumulation in aboveground part of plants.

Key words: Rice-duck farming, Manual weeding, Chemical weeding, Species diversity, Evenness, Similarity