The Sustainable Utilization Study Of 18 Introduced Excellent Cultivars Mixture Pastures Productivity And Community Stability

The mixture pastures has increased the enormous potential of the pasture productivity and it is very necessary that making use of well the leguminous fixation nitrogen value proceed high-elasticity energy-sensitive the production for especially the management the funds shortage condition of Chinese pastures development.661 different pasture grass and legume cultivar have been introduced into Yunnan form 18 countries by the Yunnan Livestock And Pasture Development Project.Many of these cultivars has evaluated the adaptability of dry mater yield and botany characteristic at 16 test sites in Yunnan seven different weathers type region by 20 years each ecosystem level.10 grass and 8 legume cultivars have very high dry mater yield and has filtrated adaptability more outstandingly good dainty quality in Yunnan. The mixture grass and legume cultivars proportion sows the optimum seedsman in accordance with the entirety comparison and each group has only increased the variety quantity. The paper did not apply fertilizer in sown mixture pastures and legume directly nourishment nitrogen with grass cultivars advantage has discussed the ecology mechanism of the mixture pastures primary productivity community stability and get a series of new conclusions.The main conclusions are shown as follows:1. The mixture pastures were correlation of primary productivity and had the important effect of community stability with a function community. Pastures comprise a mixture of competing species that need to be managed from one species of grass mixture one species of legumina, two species of grass mixture one species of legumina, one species of grass mixture tow species of Leguminous, tow species of grass mixture tow species of Leguminous, three species of grass mixture three species of Leguminous, four species of grass mixture four species of Leguminous, with one or more cultivars of each species for optimal and sustainable production. The function community has changed each mixture pastures a result different that material yield have included legumina species nitrogen ability and community stability2. Many species can make adequately using nature resources and improve mixture pastures.The production ability many species mixture pastures were the different adaptability with the stress tolerance abundant diversity, exaltation the ecosystem stability of mixture pastures. In sown mixture pastures advantage is bionitrogen function that legumina has higher productivity very good economic performance. The complex mixture group (8 cultivars) was the material yield obvious higher than simple group (2 cultivars) and mixture in sown pastures on their above-ground biomass was increased grown in monoculture. With the cultivars increase was enhanced the diversity of pastures richness and community stability.3. The mixture group pastures compared the DM to analyze with the RYT value: the species more cultivar group more its RYT value is more high,Over 3 cultivar group the value of RYT＞1 were explained these mixture group population with the time different between each group correlation summation≥1, the mixture group direct-interference-competition was opposite lower, when the population is common to make use of the resources more availability than in monoculture. But only there was 2 RYTs of mixture group of almost≧1, the mixture groups have no interference or exist dissymmetry interference. Express this entire mixture group contains good interspecies compatibility.4. the sown mixture pastures of the different community stability has no with cultivar number the relativity, there were 28 mixture group the inside only 8 mixture group to appear the significant regression relation: They were a G1, G9, G12, G13, G16, G19, G21 with G26, linear correlation to return with equilibrium line mutually, expressed a 8 mixture group community for falling can attaining stability, explaining high yields community the uncertain stability.The leguminous community were whole proportion different of when the different cultivar group community attaining stability, leguminous was occupying too not same alike. With leguminous-grass rate and time an extension more and more leguminous was in the ascendant. 5. An important index sign that community stability is the sown mixture pastures productivity with sustainable using production but the main influence was the interspecies compatibility or interference activity with mixture group diversity.Grass pasture Wittet of Kikuyu grass, Narok of Setaria with the leguminous pasture Safari of Kenya white clover, Haifa of White clover have formed interspecies better compatibility, in sown pastures community of stabilization the balance.6. The mixture pastures mows influence of the material yield, over many mowing close the ground will finally make nourishment exhaustion inside the plant, become the flimsiness. Two months mowing once, the leguminous-grass pastures has enough and regrowing time with the leave stubble of the high 3cm in mows, growing to the valid control grass interspecific competition and promoted the leguminous tiller ability has obvious function, enhanced material yield and increased the leguminous proportion very suitable cultivars in the area.7. The pastures economy production and ecological benefit point of view: the sown pastures is especially permanent the sown pastures with many cultivars mixture for good, the leguminous-grass pastures cultivars mixture the best, the leguminous intergrowth nitrogen fixation was availability metabolize process of the leguminous-grass pastures and the leguminous was offered intergrowth microbe or little symbiosis feat environment, it acquired the nourishment to used for the growth with propagate. Different leguminous cultivars nitrogen fixation efficiency was very big different. The leguminous nitrogen fixation ability in mixture pastures was a main factor to affect leguminous mixture pastures. The leguminous cultivars nitrogen fixation efficiency was Safari of Kenya white clover first, Haifa of White clover second, Wake field of alfalfa third.8. The different mixture group had the leguminous community proportion of inside occupying too not same alike for community attaining stability. The community to attain the stability when leguminous cultivars have achieved occupying scale attains 15.3％. When the pasture population and community have grown stability especially the leguminous cultivars and grass have formed relation of mutualism or sommensalism, the pasture population and community competition inhibition were the lower.9.T 28 was a very high 8 7943.41 KgDM ha/yr in all group, the yield of between year and year was no too much the variety at still maintain more the higher yield 2003. Grass pasture Narok of Setaria1521.11 KgDM ha/yr, Wittet of Kikuyu grass1684.44 KgDM ha/yr, leguminous pasture Safari of Kenya white clover 1117.78 KgDM ha/yr, Haifa of White clover 944.44 KgDM ha/yr have been maintaining the higher level in all cultivars. Haifa of White clover has maintained the higher yield strong or weak in complex mixture group order for T 27＞T 28. the result expresses, the four cultivars mixture sown pastures was the higher yield of permanence distinct variety that Safari of Kenya white clover has made selection after the yield of DM high and low variety mode was decided Narok of Setaria and Wittet of Kikuyu grass.10. The sown pastures dry matter yield dynamic analysis in 1998-2005 When the pasture population and community have grown stability although year and year a stability has changed, especially the leguminous cultivars and grass have formed relation of mutualism or sommensalism, Safari of Kenya white clover with Wittet of Kikuyu grass and Haifa of White clover with Narok of Setaria were the higher yield of permanence distinct variety in the regional examination and extension area for optimal and sustainable production.