Soil and Water Conservation Functions of Seabuckthorn and Its Role in Controlling and Exploiting Loess Plateau

The study showed that the 5 to 7 year-old seabuckthorn stands canopy can intercept 8.5%~49.0% of annual rainfall and reduce the kinetic energy of raindrops.Its litter amounts to 5.46t·hm^-2 which has maximum water holding capacity of 15.31t·hm^-2.In the case of covering soil surface with litter of 1 cm the soil and water loss will be controlled basically. Its root system can also increase the soil anti-scourability and anti-erodibility. Compared with the soil without root system, the scoured sediment in seabuckthorn stand is decreased by 55%~88%. According to the determination in the runoff plots in rain season in 1988~1994, the seabuckthorn stands can make the most use of soil and water conservation from fourth to fifth year after its planting, and compared with farmland it decreased runoff by 87.1% and soil loss by 99.0%, respectively, owing to covering soil with litter and strengthening soil by root system.Be-sides, seabuckthorn stands can produce fuel of about 10~30 t·hm^-2 every 4~5 years, raise the content of organic matter and nitrogen in soil by 115% and 90% and the yield of fruit, on an average, 500 kg·hm^-2.All these have great significance for controlling the Loess Plateau, improving the living conditions of the local people and turning "a vicious circle into a good circle" in the region.Now such examples as in slope protection, flood control, solving the fuel wood problem and in comprehensive control of watershed are set up by seabuckthorn planting.