Abstract: The difference in N, P and K contents of hillside fields under different harvesting frequencies is investigated at Hong Kong, Heshan and Shenzhen study sites. There are significantdifferences in total and available nutrient contents among sampling locations. Soil nutrient contents on uncutting hills are significantly higher than those on often-cutting ones, and in the former case, soil N content is in the order of Hong Kong >Shenzhen >Heshan.Lower soil layers have a higher P content than upper often-cutting hill has a highernutrient content at Shenzhen than at Heshan. It is suggested that vegetation harvestingshould be done under optimal frequency and within optimal season to minimize its detrimental effect.

Key words: Vegetation harvesting, Soil nutrient, Harvesting frequency, three outfalls of Chingjiang River., indicators of hydrological alteration (IHA), eco-hydrology, the Three Gorges Reservoir, change of water regime