Study On Stocks Features And Primary Productivity About Mixed-pasture Of Alfafal (Medicago. Sativa) & Smooth Bromegrass (Bromus Inermis Less) In Oasis

This study is to select alfalfa and Smooth bromegrass which adapt to mixed planting in Xinjiang Oasis by the features of Xinjiang Oasis, and to establish the mixture ratio and the best mowing period of alfalfa and Smooth bromegrass.Data on growth,nutrition contents and biomass were collected and analyzed by AHP analysis withing a view to establishing alfalfa and Bromus inermis mixture ratio and the best period of clipping, biomass accumulation,competition between species,plant community structures andbest clipping date were studied.It is expected that relevant theory and techniques were found out for forage production in the area.The results1.The yield of mixture pasture on different cutting treatment was significantly different (P<0.05), cutting treatment T₁(showing bud period of Alfalfa ) and cutting treatment T₂ (Alfalfa early flowering) were significantly different (P<0.01);The yield of mixture pasture on different mixture ratio treatment was influenced ,the yield of mixture pasture in mixture ratio treatment A₁ (Mixture ratio of alfalfa and Smooth bromegrass is 5:5 )were the highest.2 .Clipping period has a clear impact on quality of alfalfa. in treatment T1,Crude protein content is the highest (showing bud period of Alfalfa)and NDF and ADF content are the lowest (P<0.05); Crude protein, NDF and ADF of Alfalfa were significantly different (P <0.05)between Treatment T₂ (early flowering period of alfalfa)and Treatment T₃ (flowering period of Alfalfa)during the clipping period. Clipping period of mixture pasture has the same effect on both quality of Bromus inermis and alfalfa. Generally speaking, the clipping period has significantly effect on the quality of grass of mixture pasture.3. Mixture ratio has a certain effect on quality of alfalfa in mixed pasture, treatment A₁ (Mixture ratio of alfalfa and Smooth bromegrass is 5:5) has better quality; Mixture ratio has no significant effect on the quality of Smooth bromegrass in mixed pasture, treatment A₁ has the highest crude protein (Mixture ratio of alfalfa and Smooth bromegrass is 5:5). 4.On the CR between two mixed plant (CR), Alfalfa always occupy a strong advantage, CRa of Alfalfa (CRa)is greater than competitive rate (CRv)of Smooth bromegrass during all clipping periods, And with mixture ratio of alfalfa increases, competitive rate of alfalfa become greater. Two plants have better symbiotic relationship, and occupy different or common niche in different periods and mixture ratio, and the two plants use different resources and show some beneficial relationship5.All the dynamic growth of Alfalfa and Smooth bromegrass also accord with a "slow-fast-slow" S-shaped growth curve, But growth speed show little change among the various communities ,every treatment has about 25 days of rapid growth period before mowing, during the 25 days, Alfalfa and Smooth bromegrass respectively at the branching stage-showing bud phase and jointing-booting.6.By correlation analysis of single planting alfalfa, single planting Smooth bromegrass and alfalfa and Bromus inermis mixed planting, the results show that organic matter has positive influence on the yield, and the higher the yield, the more organic matter form. In the single planting alfalfa, Hay yield of alfalfa has negative influence on available K. Hay yield of Smooth bromegrass has negative influence on available N, available P and available K. Fertilizer consumption of P and K are the largest in the mixed grass of Alfalfa and Bromus inermis.7.AHP can achieve calculation of all targets, then we can estimate total primary productivity and ecological benefits of mixed grass of Alfalfa and Smooth bromegrass. Preliminary results showed that A₁ T₂,CK₁ T₂,A₁ T₁,CK₁ T₁and A₃ T₂ has better comprehensive evaluation.