Abstract: Based on the field trial results carried out on the Loess Plateau of eastern Gansu,this paper evaluates the soil and water conservation efficiencies of several crop rotation patterns with the methods of analytic hierachy process(AHP)and quantitative classification.The results shOw that crop rotation patterns with the best soil and water conservation efficiencies are corn-wheat+bean+corn,corn-millet-corn,corn-wheat+bean-millet,corn-corn-millet,corn-wheat+bean-potato and mil-let-corn-corn

Key words: Pinus massoniana, provenance, heterogeneous low P stress, root architecture, phosphorus efficiency.