紫色土区不同土地利用类型土壤紧实度特征

以重庆市沙坪坝区杨家沟小流域为例,选取6种土地利用类型样地进行试验,研究紫色土区不同土地利用类型的土壤紧实度特征,为土壤质量评价和土地资源管理提供参考。通过多重比较检验分析土壤紧实度随土壤深度的变化规律以及不同土地利用类型下的差异,结果表明:(1)6种土地利用类型的土壤紧实度值为竹林地园地灌木林地林地草地旱地;(2)6种土地利用类型的土壤紧实度均随土壤深度增加而增大,但各类之间变化差异较大;(3)同土层而言,0~10cm土层旱地与其它5种土地利用类型的土壤紧实度有显著性差异(p0.05),但各种土地利用类型间底层土壤紧实度差异不明显;不同土层而言,0~10cm土层与其它3个土层有显著性差异(p0.05),由于0~10cm土层受耕作、踩踏等外力扰动与其它土层差异较大。10~20cm土层与其它3个土层也有显著性差异(p0.05)。其它各土层之间差异不明显。不同土地利用类型的土壤紧实度差异较大,主要与人类活动扰动程度有关。

Characteristics of Soil Compactness under Different Land-use Types in Purple Soil Region

Yangjiagou catchment in Shapingba District, Chongqing City, China was sampled to study the characteristics of soil compactness under different land-use types to provide scientific basis for soil quality assessment and land resource management in purple soil region. Soil compactness change with soil depth and land use types was studied using multiple comparative test analysis. Results show that 1)the soil compactness under six land use types are decreasing sequenced as bamboo land, orchard land, shrub land, forest land, grassland and dry land; 2)the soil compactness increase with increasing soil depth in six land use types, but are obvious different occurred among different land-use types; 3)for the same soil layer, the soil compactness of the 0~10 cm topsoil in the dry land is different from other five types(p <0.05); however, the bottom layer soil compactness has no significant differences among various types. For the different soil layers, affected by external force such as cultivation, trampling disturbance, the soil compactness of the 0~10 cm topsoil are significant different from other soil layers. Significant differences also occurred in 10~20 cm soil layer with other three layers(p<0.05). Due to the boundary between the topsoil of disturbed and the bottom layer soil of stabilization, soil properties are different between topsoil and bottom layer. However, there are no obvious differences among other layers. Soil compactness varies with land use types, with close relation to human disturbance degrees. Thanks to a combination of reduced agricultural activities and increased soil depth, the soil compactness is becoming higher.