Abstract: The soil nutrients of the interplanted herbage of apple orchard in Weibei areas in the loess plateau were studied. Results showed that the content of soil organic matter within 60 cm soil layer was increased by 0.1% in grass family herbage land and by 0.15% in the pulse family herbage per year respectively. With growing herbage years, the soil organic matter increased in dept soil layers.Effects of herbage-interplanted on total N, P and K were within 40 cm soil layer. Nutrient competition existed between herbage and apple tree within 40cm soil layers in four years after planting herbage. In the fifth year of herbage growth, the content of total N, P and K were increased. The content of total N, P and K appeared "S" type change within five years. But the content of hydrolytic N, available P and available K within 40cm soil layer was increased. The activated organic P and hydrolytic N were different in the various kinds of herbage lands. The activated organic P in perennial ryegrass land was more effectively than that in white clover land. The hydrolytic N in white clover land was increased in compared with perennial ryegrass land. With growing herbage years,fruit output and quality were enhanced.

Key words: Planting herbage, The loess plateau, Apple, Orchard, Soil nutrient