Wang Xiang, Jiao Ju-Ying, Cao Xue, Li Jian-Jun, Bai Lei-Chao, Sun Xiao-Chen
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, China.
Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China.
Ying Yong Sheng Tai Xue Bao. 2022 Mar;33(3):765-774. doi: 10.13287/j.1001-9332.202203.011.
As a special bio-geomorphic landscape in the Qaidam desert area, nebkhas play a critical role in fixing quicksand, improving soil quality, and maintaining the stability of regional ecological environment. Taking the nebkhas with coverage of approximately 15%, 25%, 45% and 60% in Gahai Lake area of Qaidam Basin as the research objects, we analyzed the vertical distribution and enrichment characteristics of soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkali-hydrolyzable nitrogen (AN), available phosphorus (AP) and available potassium (AK). The results showed that the contents of SOM, TN, TP, TK, AN, AP and AK varied in the range of 1.67-10.22 g·kg, 0.05-0.42 g·kg, 0.31-0.54 g·kg, 15.87-18.84 g·kg, 2.26-11.68 mg·kg, 0.80-15.00 mg·kg and 45-161 mg·kg, respectively. Vertically, soil nutrients in the nebkhas with 15% coverage showed a decreasing trend first then increased, and then decreased again with the increase of soil depth, except for TP, which did not show any significant change. In the nebkhas with 25%, 45% and 60% coverage, SOM, TN, AN, TP and AP all showed a decreasing trend with increasing soil depth ,whereas TK and AK did not change significantly with soil layer. Above the nebkhas ground level of , SOM, TN, TK, AN, AP and AK were all enriched, especially in the surface layer.Aamong all the nutrients, the enrichment rate of AN reached 5.19. In addition, below the nebkhas ground level of , TN, AN, TK, AK and AP also showed enrichment. SOM, TN, AN, TP, AP, TK and AK were all significantly positively correlated with soil water content, and negatively correlated with altitude. All nutrients except TP were mainly affected by altitude. In conclusion, soil nutrient content of nebkhas was the highest in the surface layer, the enrichment effect of which was not only reflected in the interior of the nebkhas, but also below the ground level of the nebkhas. Our results could provide reference for the scientific utilization of nebkhas and ecological environment protection in Qaidam Basin area.
作为柴达木沙漠地区一种特殊的生物地貌景观，灌丛沙堆在固定流沙、改善土壤质量以及维持区域生态环境稳定方面发挥着关键作用。以柴达木盆地尕海湖地区覆盖度分别约为15%、25%、45%和60%的灌丛沙堆为研究对象，我们分析了土壤有机质（SOM）、全氮（TN）、全磷（TP）、全钾（TK）、碱解氮（AN）、有效磷（AP）和速效钾（AK）的垂直分布及富集特征。结果表明，SOM、TN、TP、TK、AN、AP和AK的含量分别在1.67 - 10.22 g·kg、0.05 - 0.42 g·kg、0.31 - 0.54 g·kg、15.87 - 18.84 g·kg、2.26 - 11.68 mg·kg、0.80 - 15.00 mg·kg和45 - 161 mg·kg范围内变化。垂直方向上，覆盖度为15%的灌丛沙堆中，除TP无显著变化外，土壤养分随土层深度增加先降低后升高，再降低；覆盖度为25%、45%和60%的灌丛沙堆中，SOM、TN、AN、TP和AP均随土层深度增加呈降低趋势，而TK和AK随土层变化不显著。在灌丛沙堆地面以上，SOM、TN、TK、AN、AP和AK均有富集，尤其在表层。在所有养分中，AN的富集率达5.19。此外，在灌丛沙堆地面以下，TN、AN、TK、AK和AP也表现出富集。SOM、TN、AN、TP、AP、TK和AK均与土壤含水量呈显著正相关，与海拔呈负相关。除TP外，所有养分主要受海拔影响。总之，灌丛沙堆土壤养分含量表层最高，其富集效应不仅体现在灌丛沙堆内部，也体现在灌丛沙堆地面以下。我们的研究结果可为柴达木盆地地区灌丛沙堆的科学利用及生态环境保护提供参考。
