内蒙古奈曼旗中部沙地土壤剖面特征

Observation on the Profiles of Sandy Soils in the Middle Part of Naiman, Inner-Mongolia

通过对奈曼旗中部不同沙地土壤剖面特征和有机质含量分布的分析认为 :灌溉农田土壤具有 8层结构 ,沙层与粘土层交错叠置。旱作农田土壤虽然也具有 8层结构 ,但是只有一层粘土 ,撂荒地土壤只有 3层 ,而且完全是沙层 ,保水保肥性能最差。此外 ,灌溉农田土壤 0～ 30 cm土层的有机质的含量约 0 .712 g· cm- 3,旱作农田和撂荒地相应土壤层的有机质含量分别只有 0 .40 3g· cm- 3和 0 .42 0 g· cm- 3。同一土壤剖面的有机质含量随着深度的增加而减少。

Several soil profiles were observed in order to find the characteristics of sandy soil. Observation revealed that the profile of irrigated cropland has three layers of clay and five layers of sands overlaid. The soil profile of rainfed cropland includes eight layers, in which only one layer of clay is at the depth around 30 cm, the rest are sand layers. There are three layers of sand in the profile of abandoned cropland. Comparing the differences of the three profiles, it is obvious that irrigated cropland has a capacity of holding water and nutrients higher than that of rainfed cropland and abandoned cropland. Measurement on soil organic matter revealed that irrigated cropland has an organic matter content of 0\^712 g\5cm\+\{-3\}, while the organic matter content of rainfed and abandoned cropland were 0\^403 g\5cm\+\{-3\} and 0\^420 g\5cm\+\{-3\}, respectively. In the same profile, organic matter content decreased with the increase of soil depth.