Changes in soil organic carbon and nitrogen after 26 years of farmland management on the Loess Plateau of China
ZHOU Zhengchao1*, ZHANG Xiaoyan1, GAN Zhuoting2
1 Department of Tourism and Environmental Sciences, Shaanxi Normal University, Xi’an 710062, China; 2 Key Laboratory of Disaster Survey and Mechanism Simulation of Shaanxi Province, Baoji University of Arts and Sciences, Baoji 721007, China
Changes in soil organic carbon and nitrogen after 26 years of farmland management on the Loess Plateau of China
ZHOU Zhengchao1*, ZHANG Xiaoyan1, GAN Zhuoting2
1 Department of Tourism and Environmental Sciences, Shaanxi Normal University, Xi’an 710062, China; 2 Key Laboratory of Disaster Survey and Mechanism Simulation of Shaanxi Province, Baoji University of Arts and Sciences, Baoji 721007, China
摘要 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 aestivum L.) non-fertilized, wheat fertilized (mineral fertilizer and organic manure) and alfalfa (Medicago Sativa L.) 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.
Abstract: 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 aestivum L.) non-fertilized, wheat fertilized (mineral fertilizer and organic manure) and alfalfa (Medicago Sativa L.) 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.
The Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China (131025) and the Natural Science Foundation of Shaanxi Province (2014KJXX-52)
通讯作者:
ZHOU Zhengchao
E-mail: zczhou@snnu.edu.cn
引用本文:
ZHOU Zhengchao, ZHANG Xiaoyan, GAN Zhuoting. Changes in soil organic carbon and nitrogen after 26 years of farmland management on the Loess Plateau of China[J]. 干旱区科学, 2015, 7(6): 806-813.
ZHOU Zhengchao, ZHANG Xiaoyan, GAN Zhuoting. Changes in soil organic carbon and nitrogen after 26 years of farmland management on the Loess Plateau of China. Journal of Arid Land, 2015, 7(6): 806-813.
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