Changes in soil organic carbon and nitrogen after 26 years of farmland management on the Loess Plateau of China
Changes in soil organic carbon and nitrogen after 26 years of farmland management on the Loess Plateau of China
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DOI：
10.1007/s40333-015-0051-y
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发表时间：
2015-06
影响因子：
3
通讯作者：
Zheng-chao Zhou;Xiaoyan Zhang;Z. Gan
中科院分区：
文献类型：
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作者：
Zheng-chao Zhou;Xiaoyan Zhang;Z. Gan
土壤碳(C)和氮(N)在土壤和环境质量中起着至关重要的作用。本研究以黄土高原半干旱区为研究对象，研究了26 a（1984 ~ 2010）农田管理对撂撂撂撂地、小麦（Triticum aestivumL.）不施肥、小麦（矿质肥和有机肥）和苜蓿（Medicago SativaL.）不施肥处理土壤有机碳（SOC）和土壤氮(N)的影响。结果表明：退耕还田后，0 ~ 20 cm土壤有机碳和全氮含量分别增加了4.29（24.4%）和1.39 Mg/hm2(100%)；与未施肥处理相比，小麦施肥处理0 ~ 20 cm土壤有机碳和全氮含量分别提高了4.64（26.4%）和1.18 Mg/hm2（85.5%）。土壤有机碳、全氮和矿质氮随土壤深度的变化程度在苜蓿地和小麦地表层（0 ~ 30 cm）大于深层（30 ~ 100 cm）。冬小麦施肥可提高土壤有机碳和全氮积累速率，土壤有机碳浓度与土壤全氮浓度呈显著正相关。因此，本研究表明，在半干旱区，退耕还草和施肥等农田管理措施可促进土壤碳氮的固存。
Soil carbon (C) and nitrogen (N) play a crucial role in determining the soil and environmental quality. In this study, we investigated the effects of 26 years (from 1984 to 2010) of farmland management on soil organic carbon (SOC) and soil N in abandoned, wheat (Triticum aestivumL.) non-fertilized, wheat fertilized (mineral fertilizer and organic manure) and alfalfa (Medicago SativaL.) non-fertilized treatments in a semi-arid region of the Loess Plateau, China. Our results showed that SOC and soil total N contents in the 0–20 cm soil layer increased by 4.29 (24.4%) and 1.39 Mg/hm2(100%), respectively, after the conversion of farmland to alfalfa land. Compared to the wheat non-fertilized treatment, SOC and soil total N contents in the 0–20 cm soil layer increased by 4.64 (26.4%) and 1.18 Mg/hm2(85.5%), respectively, in the wheat fertilized treatment. In addition, we found that the extents of changes in SOC, soil total N and mineral N depended on soil depth were greater in the upper soil layer (0–30 cm) than in the deeper soil layer (30–100 cm) in the alfalfa land or fertilizer-applied wheat land. Fertilizer applied to winter wheat could increase the accumulation rates of SOC and soil total N. SOC concentration had a significant positive correlation with soil total N concentration. Therefore, this study suggested that farmland management, e.g. the conversion of farmland to alfalfa forage land and fertilizer application, could promote the sequestrations of C and N in soils in semi-arid regions.