Meng Tian-Ge, Wu Lu-Yao, Zhang Shao-Lei, Xu Yan-Ying, Li Xiong, Zhang Jian-Guo
Ministry of Agriculture Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Yangling 712100, China.
Huan Jing Ke Xue. 2020 Apr 8;41(4):1950-1959. doi: 10.13227/j.hjkx.201909003.
Dissolved carbon (DC) is the most active carbon fraction in soils. Vegetation restoration and reconstruction accelerate the carbon cycle in arid desert regions. Studying the DC distribution in soil profiles of artificial shelterbelt under saline irrigation can provide theoretical support and decision-making basis for artificial shelterbelt management, development, and utilization in arid desert areas. In this study, we took the artificial shelterbelts drip-irrigated with five different mineralization and one shifting sandy land (CK) along the Taklimakan Desert Highway as sampling plots, analyzed and discussed the vertical distribution characteristics of soil dissolved organic carbon (SDOC) and dissolved inorganic carbon (SDIC) in the 0-1 m profiles, and further analyzed their relationships among different factors. The results showed that SDOC and SDIC of CK and shelterbelts under 2.82 g·L irrigation showed an "" type distribution with a linear function relationship. The SDOC and SDIC of four other treatments showed a "Γ" type distribution with power function relationships. The fluctuation ability and contribution degree of SDOC and SDIC of different treatments in the surface layer were higher than those in the lower layers, and the fluctuation and contribution intensity of SDOC were higher than those of SDIC. Except for 2.82 g·L treatment, the average SDOC contents of other treatments were 2-4 times those of SDIC. The average SDOC content of 2.82 g·L treatment was lower than CK; other treatments were 3-5 times that of CK; and the average SDIC content of all treatments increased 15.0%-57.9% than CK. For the 0-5 cm layer, SDOC content increased with the irrigation water mineralization except the 2.82 g·L treatment, but SDIC content firstly increased and then decreased with increasing mineralization, and that for the 4.82 g·L treatment was highest. The SDOC and SDIC were positively correlated with EC, SOC, irrigation water mineralization, SIC, and soil moisture, for which they both showed a weak positive correlation with soil moisture; they were negatively correlated with soil depth. The SDOC and SDIC showed a weak negative correlation and a weak positive correlation with pH, respectively. In summary, the mineralization of irrigation water has an important impact on the vertical distribution of SDOC and SDIC, and their distribution also has close relationships with EC, SOC, SIC, soil moisture, and soil depth, which is of great significance for plantations in extremely drought deserts.
溶解碳（DC）是土壤中最活跃的碳组分。植被恢复与重建加速了干旱荒漠地区的碳循环。研究咸水灌溉下人工防护林土壤剖面中溶解碳的分布，可为干旱荒漠地区人工防护林的经营、开发与利用提供理论支持和决策依据。本研究以塔克拉玛干沙漠公路沿线5种不同矿化度滴灌的人工防护林和1片流动沙地（对照）为采样地，分析讨论了0-1m剖面土壤溶解有机碳（SDOC）和溶解无机碳（SDIC）的垂直分布特征，并进一步分析了它们与不同因素之间的关系。结果表明，对照和2.82g·L灌溉处理下防护林的SDOC和SDIC呈“ ”型分布，具有线性函数关系。其他4种处理的SDOC和SDIC呈“Γ”型分布，具有幂函数关系。不同处理的SDOC和SDIC在表层的波动能力和贡献程度高于下层，且SDOC的波动和贡献强度高于SDIC。除2.82g·L处理外，其他处理的平均SDOC含量是SDIC的2-4倍。2.82g·L处理的平均SDOC含量低于对照；其他处理是对照的3-5倍；所有处理的平均SDIC含量比对照增加了15.0%-57.9%。对于0-5cm土层，除2.82g·L处理外，SDOC含量随灌溉水矿化度增加而增加，但SDIC含量随矿化度增加先增加后降低，4.82g·L处理的SDIC含量最高。SDOC和SDIC与电导率（EC）、土壤有机碳（SOC）、灌溉水矿化度、土壤无机碳（SIC）和土壤水分呈正相关，其中它们与土壤水分均呈弱正相关；与土壤深度呈负相关。SDOC和SDIC与pH分别呈弱负相关和弱正相关。综上所述，灌溉水矿化度对SDOC和SDIC的垂直分布有重要影响，其分布还与EC、SOC、SIC、土壤水分和土壤深度密切相关，这对极端干旱荒漠地区的人工林具有重要意义。
