太行山低山丘陵区不同土地利用条件下土壤容重空间变化特征

Spatial Variability of Bulk Density under Different Land Use Types in the Slope of Low-Land in Tai hang Mountains

通过对太行山低山丘陵区人工立体石榴林工程的调查,结果表明：不同土地利用类型土壤容重值大小依次为：坡谷石榴地（1.16g/cm^3）〈中坡石榴地（1.27g/cm^3）〈坡谷台田（1.30g/cm^3）〈中坡草地（1.32g/cm^3）;中坡位土壤容重值大于坡谷;耕作层（0～20cm）土壤容重在台田和草地之间以及石榴地之间没有明显差异,坡谷石榴地的土壤容重值最低（1.32g/cm^3）,中坡草地的土壤容重最高（1.56g/cm^3）,深层土壤（40～60cm）的土壤容重在相同坡位没有明显差异。土壤容重随着采样深度增加的总趋势,但坡谷台田和中坡草地土壤容重在10～20cm土层最低;统计表明0～5cm、10～20cm土壤容重属于中等变异性,其余土层土壤容重属于弱变异性。从土地利用类型和坡位来分析土壤容重空间变化特征,对于其它影响因子的影响有待于进一步的研究。

The project of artificial pomegranate orchard stand located at the hilly region of Tai hang Mountain was investigated. The results suggested that soil bulk density in topsoil （0 to 20 cm） under different land use types followed the order that pomegranate orchard stand in valley （1.16 g/cm^3） 〈pomegranate orchard stand in middle slope（ 1.27 g/cm^3） 〈terraced field in valley（ 1.30 g/cm^3） 〈grassland in middle slope （1.32 g/cm^3）. The soil bulk density in middle slope was higher than that in the valley. There was no significant difference in the soil bulk densities of plough layers （0 to 20 cm） in terraced field, grassland and pomegranate orchard stand. Pomegranate orchard stand in valley had the lowest soil bulk density （1.32 g/cm^3）, while grassland in middle slope had the highest soil bulk density （1.56 g/cm^3）. The soil bulk density of deep soil （40 to 60 cm） at the same slope position showed no significant difference. Soil bulk density increased with the increase of soil depth. But the soil bulk densities of terraced field in valley and grassland in middle slope reached their lowest value at the 10 to 20 cm layer. The soil bulk densities of 0 to 5 cm layer and 10 to 20 cm layer showed moderate spatial variability statistically, while that of other soil layers showed smaller spatial variability. This paper only probed the spatial variability characteristics originated from land use types and slope positions. Other factors that caused spatial variability need further investigation.