Studuy On Analysis Of Main Factors Affecting Wheat And Respond Of Life-history Of Weed In Semiarid Areas

From 2008 to 2009 we selected 10 native weeds and planted them in differentially treated cropland on fixed quadrants for the purpose to research the correlation among three factors affecting yield in spring wheat and to research the respond to environment factors of the weed community structure in semiarid cropland, include the performance and respond to environment factors of the 10 selected weed species.The results indicated:1. Spring wheat have the highest yield on the level of 600ears/m2.In order to raise the productivity of spring wheat, effective tiller percentage must be increased,1000-grain weight (KGW) have not significant contribute to yield;2. Reasonbal density of spring wheat is effective in controlling weed;3. Effect of density of spring wheat on weed community structure was non-significant;7. The successful establishment of weed is correlated with the sowing of weed, wheat cultivars and wheat density. The significance of correlation have changed with years Result of Life history of weed indicated:1. The same species in different climate show different life-history strategies, Corisermum, Convolvulus arvensis and Fagopyrum dibotrys tended towards the competitor (C) strategy, stress tolerant (S) strategy and mixed competitor-stress tolerant (C-S) strategy in 2008, but stress tolerant (S) strategy, competitor-stress tolerant(CS) strategy and stress tolerant (S) strategy in 2009;2. Effect of Grime model on weed life history strategies was limited. Chenpodium glaucum, Setaia viridis and Stipa breviflora tended towards the ruderal (R) strategy in 2008, but haven't showed the ruderal (R) strategy in 2009. Elsholzia argyi,Androsace ncana and Potentilla bifurc in the two years and Salsola collina Pall in 2008 haven't showed life-history strategies significance, Salsola collina Pall tended towards the stress tolerant (S) strategy in 2009;3. With the variety of the ascendancy environment factors, life-history strategies according to change, that is, characteristics of life history respond to ecological attribute, so plant functionality have move in C-R-S axis of Grime model. Fagopyrum dibotrys tended towards a mixed stress tolerant-ruderal(S-R) strategy, Convolvulus arvensis tended towards a mixed competitor-stress tolerant(C-S) strategy in annual variety from 2008 to 2009;4. In a word, Corispermum declinatum tended towards competitor-stress tolerant (CS) strategy, Chenpodium glaucumtended towards the ruderal (R) strategy, Setaia viridis tended towards the ruderal (R) strategy,Elsholzia argyi took evasive strategy, so it haven't showed life history strategies, Stipa breviflora tended towards the ruderal (R) strategy, Fagopyrum dibotrys tended towards the stress tolerant (S) strategy, Convolvulus arvensis tended towards the stress tolerant (S)strategy, Salsola collina Pall tended towards the stress tolerant (S)strategy Androsace incana, Potentilla bifurcs took evasive strategy, so it haven't showed life history strategies.