Ecological circle way and coupling effect of fruit-grass-chicken mode in dry highlands of the Loess Plateau

Because of ecological fragility and lack of water resources, traditional planting mode of grain and industrial crops has severely affected and restricted the sustainable development of agriculture in dry highlands of the Loess Plateau. Thus based on resource characteristics and ecological conditions of dry highlands of the Loess Plateau, a mode for sustainable agricultural development was established based on ternary planting of grain crops, industrial crops and grasses. The mode involved the application of the theory of system coupling and ecological cycle along with the combination of ecological conservation and efficient production. It provided the critical link for the realization of sustainable development of regional ecological and economic co-ordination in dry highlands of the Loess Plateau. Using Qingyang City in the Central Loess Plateau as the study area, an ecological cycle mode of fruit-grass-chicken was designed based on the characteristics of agricultural resources and economic development. Then the cyclic structure of the mode was configured using coupled functionality of industries in Qingyang City. Technical specifications were put forward and the effect of coupling analyzed for Qingyang City. The results showed that the mode output coupling production by the combination of the three subsystems of fruits, grass and chicken. The mode improved species structure of orchard ecosystems, increased utilization rate of agricultural resources, enhanced energy conversion and recycling of the orchard ecosystems. Compared with single orchard cultivation, per-unit-area profit increased by 3.82 times, water use efficiency increased by 54.1%, water/soil erosion decreased by 58.82%, application rate of chemical fertilizers/pesticides decreased by 25.24%/5.56% and utilization rate of land resources increased by 36.84%. Therefore, the established mode had significant ecological and socio-economic benefits, with a wide range of applications and promotional values in the Loess Plateau.