Zhao Jing-Jing, Gong Lu, An Shen-Qun, Li Yang-Mei, Chen Xin
College of Resources and Environment Science, Xinjiang University, Urumqi 830046, China.
Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi 830046, China.
Huan Jing Ke Xue. 2018 Jul 8;39(7):3373-3381. doi: 10.13227/j.hjkx.201711099.
Studying the characteristics of soil organic carbon (SOC) and soil inorganic carbon (SIC), and their relationship with environmental factors is helpful for understanding soil ecological processes, and providing theoretical support for research on the global carbon budget. Based on the oasis in the northern margin of Tarim Basin, this study analyzed the characteristics of the soil carbon pool, and, combined with redundancy and path analyses, explored the relationship between SOC and SIC, and their environmental factors. The results showed that there was a significant difference (<0.05) in SOC and SIC contents in cotton fields with different continuous cropping years (<0.05). With an increase in continuous cropping years, the SOC content increased firstly and then decreased, while the SIC content decreased firstly and then increased (<0.05). The SOC content was the highest in the 0-20 cm layer, while the SIC content was the highest in the 20-50 cm layer. The importance of environmental factors on the characteristics of the soil carbon pool was deduced by redundancy analysis. The order of importance was phosphatase activity > pH > sucrase activity > catalase activity > total N > available P > available K > soil moisture content > urease activity > electrical conductivity (EC); phosphatase activity, pH value, invertase activity, catalase activity, total nitrogen, available phosphorus, and available potassium showed significant correlation with SOC and SIC (<0.01). Soil moisture and urease activity showed significant correlation with SOC and SIC (<0.05). The path analysis showed that available P had a direct effect on the SOC content; it was the main factor affecting it. The urease activity had a direct effect on SIC; it was the main factor affecting it. This study of soil carbon pools in arid and semiarid regions is the basis for evaluating the "source/sink" effect of soil carbon in farmland ecosystems, and is of great significance for studying the global carbon budget and land carbon cycle mechanism.
研究土壤有机碳（SOC）和土壤无机碳（SIC）的特征及其与环境因子的关系，有助于理解土壤生态过程，并为全球碳预算研究提供理论支持。基于塔里木盆地北缘绿洲，本研究分析了土壤碳库特征，并结合冗余分析和通径分析，探讨了SOC和SIC及其环境因子之间的关系。结果表明，不同连作年限棉田的SOC和SIC含量存在显著差异（<0.05）。随着连作年限增加，SOC含量先增加后降低，而SIC含量先降低后增加（<0.05）。SOC含量在0-20cm土层最高，而SIC含量在20-50cm土层最高。通过冗余分析推导了环境因子对土壤碳库特征的重要性。重要性顺序为：磷酸酶活性>pH>蔗糖酶活性>过氧化氢酶活性>全氮>有效磷>速效钾>土壤含水量>脲酶活性>电导率（EC）；磷酸酶活性、pH值、转化酶活性、过氧化氢酶活性、全氮、有效磷和速效钾与SOC和SIC呈显著相关（<0.01）。土壤含水量和脲酶活性与SOC和SIC呈显著相关（<0.05）。通径分析表明，有效磷对SOC含量有直接影响，是影响SOC含量的主要因素。脲酶活性对SIC有直接影响，是影响SIC的主要因素。本研究对干旱半干旱地区土壤碳库的研究是评估农田生态系统土壤碳“源/汇”效应的基础，对研究全球碳预算和陆地碳循环机制具有重要意义。
