Influence Of Forage Grows, Photosynthesis Characteristic, Soil Physical And Chemical Properties In Intercrop System Of Chinese Prickly Ash And Pasture

Peple now pay more and more attention to environment which are one of main problems the world is confronted with .Sustainabledevelopment comes to be an object people aim at .In order to achieve the effective ,harmonious and sustainable development of the local social-economic-natural compound ecosystem ,the core of ecological forestry construction should be regulationg the social ,economic and natural systems rationally in accord with the principle of the applicable ecosystem management .Long time ago ,single management has restricted the development of forest practice .Low benefit and soil productivity are the prominent characteristics ,so the sustainable development of forest is held back . Tree-grass complex has played an increasingly important role in the solution of local agro-forest confliction for land ,expoitation of biological resources ,balance of resource utilization ,environmental conservation ,improvement of food production ,and so on. At the same time ,linxia gansu province is arid and sem-iarid,and the soil is proven and less than what their need, ecological forestry and economic forestry play an impotent role in local. So finding new models to develop forest is meaningful.This research was basted on"Tianbao"project——the generalization of forestry intercropping with alfalfa ,Onobrychis and other forages which is the project of state forestry Bureau scientific and technological payoffs transformation ,and according to the topic dairy high quality forage grass production engineering reseatch and development——northwestern highly effective tree-grass intercropping pattern and technical systern research which is the project of"shi yi wu"national science and technology support . Tish research is located in linxia gansu province ,baded on 9 years Chinese prickly ash intercropping with alfalfa ,white clover and bird's foot trefoil.We studied the ecological and economic efficiency using econology principle and method.This paper summarizes the tree-grass complex system, the results show that :(1) From the phenophase from the interplanting of plants and Chinese prickly ash,we may discover that :the phenophase of Wheat and Chinese prickly ash is overlap, so the wheat's growth is serious influenced by the Chinese prickly ash tree, but interplanting with forage grass main lengthens the nutrition vegetal period and harvest more grass. What grows is quickest in mid-May, the lotus corniculatus grows may reach the 4.515cm/d, and the alfalfa reaches the 2.920cm/d. But the wheat's first high vegetal period is at the beginning of May, approximately 2.74cm/d.(2) The photosynthesis curve of three kind of leguminous forage is double peak type, moreover the morning first peak is higher than the second . The first peak of three pasturages respectively are: Alfalfa is 10.89μmolCO₂m^-2s^-1, lotus corniculatus is 8.94μmolCO₂m^-2s^-1, white clover is 5.13μmolCO₂m^-2s^-1, but the second peak value respectively is: Alfalfa is 4.10μmolCO₂m^-2s^-1, lotus corniculatus is 4.45μmolCO₂m^-2s^-1, white clover is 4.64μmolCO₂m^-2s^-1. Through the Dagneli light response curve fitting is good and obtains the light saturation points is: Alfalfa 2367μmolCO₂m^-2s^-1, lotus corniculatus 2198μmolCO₂m^-2s^-1, white three 1475μmolCO₂m^-2s^-1; The light compensation point is: Alfalfa 40.49μmolCO₂m^-2s^-1, lotus corniculatus 15.19μmolCO₂m^-2s^-1, white three 44.28μmolCO₂m^-2s^-1; The apparent quantum yield is: Alfalfa 0.065mol/mol^-1, lotus corniculatus 0.024mol/mol^-1, white three 0.098mol/mol^-1.(3) Tree-grass interplanting may enhance the soil moisture content,play an impotent role in self-control water source. Through variance analysis the soil moisture of interplanting show that: the soil moistrte of alfalfa interplanting with Chinese prickly ash has the significance difference in four different depth, particularly 6cm and 10cm also have the extremely significance difference; The interplanting with lotus corniculatus and white clover also has significance difference in different depth . The soil moisture of tree-grass complex is 3.55%, 3.02%, 3.63%, 3.38% higher than solid planting of trees on 6cm,10 cm,15cm,20 cm .(4) The forage grass root system distribution is reflects the persisting soil ability, particularly the distribution of surface layer. The root system distributed situation is: In 0-5cm white clover , the lotus corniculatus, the alfalfa and the comparison (dry weight) is 1595Kg/hm2,1025.833Kg/hm2,1113.3 Kg/hm2, 100 Kg/hm2 ,occupies the total biomass 67.73%, 42.39%, 42.24% and 14.47%. In the 0-5cm soil white clover , the lotus corniculatus and alfalfa's capillarity root quantity respectively is 902.5 Kg/ hm2, 630Kg/ hm2, 432.667Kg/hm2.(5) The soil fertility of three kind of tree-grass interplanting patternshow that : As a result of the strong own nitrogen-fixing capacity of leguminous forage. On the nitrogen's content, the intercropping with alfalfa, lotus corniculatus and white clover is 14.35 mg/Kg, 14.76 mg/Kg and 6.51 mg/Kg higher than not interplanting. The variance analysis result show that the interplanting with alfalfa and lotus corniculatus has extremely significance difference with unintercropping.(6) The economic outputs of interplanting show that : Alfalfa's annual output is highest, reaches 549.72Kg/ 667m², next is white three , is 271.79 Kg/667m², lotus corniculatus's output is 252.16Kg/667m². The two harvest in one year show that alfalfa's fresh output is the highest in the first stubble,is reaches 1782.37Kg/667m², but the second stubble, white clover fresh grass output is 68.18Kg/667m² higher than alfalfa, but the alfalfa of hay output is still highest ,teaches 105.65Kg/667m². Interplanting of wheat the fresh output is 1181.83 Kg/667m²,1374.02 Kg/667m² and 1700.85 Kg/667m² lower than alfalfa, lotus corniculatus and white clover .but the dry matter quantity of wheat is 85.38 Kg/667m² higher than the alfalfa.