旱地农田生态系统及稳态机制研究

Research On Rainfed Farmland Ecosystem and Its Stable Mechanism

从1984—1986年在甘肃中部半干旱地区定西县鹿马岔试点。对旱地农田生态系统的组成、初级生产力、物质和能量转化效率以及稳态机制进行的研究看出,旱地农田生态系统的组成相对较为复杂,因受到生态环境的胁迫,其生产力较低,物质循环和能量转化也是低水平,不平衡。可是,旱地农田生态系统在长期的演替过程中,形成了一系列旱地农业赖以发展的稳态机制。作物种类的多样化,增加了系统的稳定性,大面积种植豆科作物,增加了土壤肥力的稳定性;耕作制度的多样化,增加了系统生产力的稳定性;旱地作物对生态的适应性,增强了作物耐力的稳定性等。

In the years of 1984-1986,research was carried out on the composition,primaryproductivity,conversion efficiency of materials and energy and stable mechanism of rainfedfarmland ecosystem in Lumacha Experiment Base,Dingxi County,Central Gansu Provincein the Semiarid areas.Results showed that the composition of rainfed farmland ecosystemwas relatively complicated,and that its productivity was low,and material cycle and energyconversion were also low and uneven because of being subject to ecological environmentstress.Nevertheless,in long-term evolution process,rainfed farmland ecosystem hasformed a series of stable mechanism on Which dryland farm can depend.The diversifiedcrop pecies increase the stability of farmland ecosystem.Planting legume species on a largearea can increase the stability of land fertility,while the diversified farming tillages also givethe stability of productivity of farmland ecosystem.The ecological adaptability of drylandcrops can strengthen the stability of crop tolerance.