Ecological And Economical Benefits Analysis Of Forest-grass Compound Management Typical Patters In The Zhuanglang County Of Gansu

Forest-grass intercropping is a portion of agro-forest system, a combination of land utilization and engineering, and a consciously temporal-spatial management of perennial trees and annual grasses within the same land unit. Despite of its long history forest-grass has been adopted in conversion of farmland to forest for establishing large forestry ecology. It 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.Evaluation and analysis of ecological and economic benefits of five representative forest-grass intercropping patterns were done in comparison with farmland in the loess hill and gulch area in the Zhuanglang County of Gansu province. These patterns are Populus alba with Medicage. sativa, Prunus. tabulaeformis with Medicage. sativa, Prunus. armeniaca var.ansu with Medicage. sativa, Hippophae rhamnoides subs Prunus.sinensis with Medicage. sativa, Robinia pseudoacacia with Medicage. sativa. The results are as follows:(1) Intercropping of Prunus.tabulaeformis with Medicage. sativa was the best in conserving soil and water whereas Hippophae rhamnoides subsPrunus.sinensis with Medicage. sativa was the least, with Prunus. armeniaca var.ansu with Medicage. sativa being the most effective in changing small climate and fixing carbon and releasing oxygen.(2) The ecological benefits were 4644.72 yuan/ha for Populus alba Var.pyramidalis with Medicage. sativa, 5124.2 for Prunus. armeniaca var.ansu with Medicage. sativa, 5392.39 for Prunus. armeniaca var.ansu with Medicage. sativa, 4475.09 for Hippophae rhamnoides subs Prunus.sinensis with Medicage. sativa, and 4780.5 for Robinia pseudoacacia with Medicage. sativa.(3) The total input was the highest for Prunus. armeniaca var.ansu with Medicage. sativa and the lowest for Hippophae rhamnoides subs Prunus.sinensis with Medicage. sativa; the output was the most for Prunus. armeniaca var.ansu with Medicage. sativa and the least for Hippophae rhamnoides subs Prunus.sinensis with Medicage. sativa; the period of economic return was the shortest for Prunus. armeniaca var.ansu with Medicage. sativa and the longest for Hippophae rhamnoides subs Prunus.sinensis with Medicage. sativa.