Research On Function Of Agro-fruit Ecological System In The South Of Loess Plateau

The interrelation of structure and function of Agro-fruit ecological system was studied by investigating the biomass of plant, searching relative data and analyzing character of material cycle and energy flow of agriculture, fruiter and livestock fanning subsystem of Xipo village, Run town, Chun Hua county and Feimahe and Nangou village, Liu Lin town, Yan An city, in Shaanxi Province, in the south of Loess Plateau. The results followed as:The structure of Agro-fruit ecosystem was massive inserted, which was composed of agriculture, fruiter and livestock farming circulars. The productivity of system was restricted by ratio of them. The higher ratio of agriculture subsystem was, the higher productivity of biomass was and the lower economic productivity was. The fruiter subsystem was contrary. Advanced livestock farming could afford more organic fertilizer that is advantageous to the development of agriculture and fruiter. In addition, the productivity of system was also restricted by rational species structure among all subsystem.Fertilized input was main input, in Agro-fruit ecosystem. The nutrient element N-. P was inputted by inorganic fertilizer, P was by organic fertilizer. In Xipo, Feimahe and Nangou, the output-input ratio of N element was 0.397,0.293,and 0.204 respectively; the biological cycle rate of N, P and K in Feimahe village was faster than the others because of the bigger ratio of fruiter.Supplementary energy input of farming subsystem was still in lower level in all Agro-fruit ecological system. The input organic energy was lower and the input inorganic energy was higher, which leaded to lower energy flow index. Although the supplementary was improved in fruit subsystem, the level was still lower. In the villages of Xipo, Feimahe and Nangou, the efficiency for solar energy utilization of Agro-fruit ecosystem were 0.38% ^ 0.29% and 0.25% respectively .According to the theories of holography biology, Agro-fruit ecological systems were evaluated by the energy flow. The result showed Feimahe was good and Nangou was bad in sustainable development. Effectiveness analysis indicated livestock farming should been developed in every village; Xipo needed control growth of population; Nangou needed adjust industrial structure.