Influence of Biological Treatments on Soil and Water Conservation and Tree Growth and Development in Orange Orchard

Three years experiments of soil and water conservation with biological treatments such as planting creeping orchid on terrace walls and interplanting soybean。peanut，etc. on terrace levels in mountainous young orange orchard indicated that，the effects of soil and water conservation increased by 395. 4一412. 0 0 o over control，alkalized nitrogen in soil increased by 316. 6--466.0% over control, available P increased by 233. 3一333. 3% and available K increased by 85. 7一100% .The amount of sprouted shoots of orange increased by 48. 2一71.42% over control and the fruit yield per tree increased by 58. 7一75.2%.