Application of Gray Relevant Analysis in Cultivation Mode Evaluation of Shrub-Grass Composite:A Case Study of Hot-Arid Valley of the Jinsha River in Yongsheng County,Yunnan

Based on the effectiveness of soil improvement,8 composite shrub-grass cultivation modes were established and evaluated in 2005 in the degraded mountain areas in hot-arid valley of the Jinsha River in Yongsheng County,Yunnan Province.The soil improvement contribution value of different shrub-grass cultivation modes was evaluated by gray relation analysis and cluster analysis according to the evaluation indices including soil organic matter,total N,total P,total K,available N,available P,and available K.The results show that the gray relation degree(r=0.773) and contribution value of 'Cajanus cajan L.Millsp.+ Setaria sphacelata(Schumach.) Stapf C.E.Hubb. cv.Narok + Festuca arundinacea L.cv.Fine Lawn + Macroptilum atropurpureum(DC.) Urban + Trifolium repens L.cv.Haifa + Trifolium hybridum L.' were highest among the evaluated composite shrub-grass modes.The selected shrub-grass cultivation mode is appropriate for broadly application and believed effective for the soil ecological restoration in the degraded mountain areas in hot-arid valley of the Jinsha River.