Level terracing is a common forestation practice in the semiarid hilly-gully area of the Loess Plateau in China.To study the impacts of the practice on artificial forests

soil moisture and nutrient condition in a 20-year-old dense artificial Pinus tabulaeformis forest was evaluated.The average soil moisture content at the end of rainy season was found to be 6.94% in the 0—60 cm layer and 4.53% in the 60—160 cm layer

while it was 5.43% in the whole soil profile(0—160 cm).This indicates that the soil moisture level is not replenished significantly during rainy season.Alkali solution N

available P and K

organic matter

and total N were significantly concentrated within 10 cm of soil surface

while total P and K showed insignificant surface accumulation.The pH values at all sites were higher than 8.The average contents of total P and K and available P and K in the 0—100 cm layer were all in middle level

but the average contents of organic matter

total N

and alkali-solution N were low or very low.Result from the study suggests that in the semiarid Loess Plateau with insufficient precipitation

dense artificial forest may lead to soil moisture and nutrient condition deteriorating and that artificial thinning is an important work in later stage management of artificial forests.