Study On The Effects Of Alfalfa And Smooth Brome Mixture Artificial Grassland In Alkili-Saline Grassland

The vast alkalinized-salinized grassland in the Songnen Plain has a high economical value and an important ecological signification, are suffering from degradation resulting from soil alkalization and salinization. Artificial grassland is an effective measurement in lkalinized-salinized grassland improvement. Alfalfa and smooth brome is one of most perfect combination in the establishment of artificial grassland.In order to offer theoretic evidence for improving of alkalinized-salinized grassland in the Songnen Plain, the characteristics of plant community and soil of Alfalfa and smooth brome mixture artificial vegetation were studied in this paper. The results showed that:1) There are 21 plant species in the mixture artificial vegetation system, belong to 6 families and 18 genus.Among these species, Gramineae family has large number and the perpetration is 38.09%. The dominate species of one year artificial vegetation are annual grass family such as Chloris virgata, Setaria viridis, Echinochloa crusgalli. The dominate species of two year and three year artificial vegetation are Medicago sativa L and Bromus inermis Leyss.2) Growth mode of the first is "depress-increase-depress", the fast growth period is July to August,and the growth velocity for one day was 0.5047cm.Growth dynamic of the second year and third year was "slow-fast-slow", the fast growth period is June to July.3) The total biomass and productivity of mixture artificial community in the first year were significant difference with the second year and third year, productivity of the second was 2.84 times higher than that of first year, and 3.17times for the third year. The seasonal dynamic equation of productivity was:y=-57.527x2+513.34x-153.76, R2=0.8983.4) Alfalfa and smooth brome mixture artificial vegetation improved the soil physical and chemical quality significantly and increased soil nutrition. The content of soil organic matter in the third year alfalfa and smooth brome mixture artificial vegetation was 2.84 times compared with alkalinized-salinized grassland, the total nitrogen increased 200% and total phosphor was 94.6%.5) Alfalfa and smooth brome mixture artificial grassland can be used for the improvement of alkalinized-salinized grassland in the Songnen Plain, productivity increased and effects were significantly.