中国北方长期轮作下小麦和玉米残茬对土壤有机碳的贡献

Contributions of wheat and maize residues to soil organic carbon under long-term rotation in north China.

作者信息

Wang Jinzhou, Wang Xiujun, Xu Minggang, Feng Gu, Zhang Wenju, Yang Xueyun, Huang Shaomin

机构信息

1] Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China [2] Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20740, USA [3] College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094, China.

1] College of Global Change and Earth System Science, Beijing Normal University, Xinjiekouwai Street No.19, Haidian District, Beijing 100875, and Joint Center for Global Change Studies, Beijing 100875, China [2] Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20740, USA [3] State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, China.

出版信息

Sci Rep. 2015 Jun 23;5:11409. doi: 10.1038/srep11409.

DOI:10.1038/srep11409

PMID:26100739

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4650633/

Abstract

Soil organic carbon (SOC) dynamics in agro-ecosystem is largely influenced by cropping. However, quantifying the contributions of various crops has been lacking. Here we employed a stable isotopic approach to evaluate the contributions of wheat and maize residues to SOC at three long-term experimental sites in north China. Soil samples were collected from 0-20, 20-40, 40-60, 60-80 and 80-100 cm after 13 and 20 years of wheat-maize rotation, and SOC and its stable (13)C composition were determined. Our data showed that the δ(13)C value of SOC varied, on average, from -22.1‰ in the 0-20 cm to -21.5‰ in the 80-100 cm. Carbon input through maize residues ranged from 35% to 68% whereas the contribution of maize residues to SOC (0-40 cm) ranged from 28% to 40%. Our analyses suggested that the retention coefficient was in the range of 8.0-13.6% for maize residues and 16.5-28.5% for wheat residues. The two-fold higher retention coefficient of wheat versus maize residues was due to the differences in the quality of residues and probably also in the temperature during the growing season. Our study highlighted the importance of crop management on carbon sequestration in agricultural lands.

摘要

农业生态系统中的土壤有机碳（SOC）动态很大程度上受种植方式影响。然而，一直缺乏对各种作物贡献的量化研究。在此，我们采用稳定同位素方法，在中国北方三个长期试验点评估小麦和玉米残茬对土壤有机碳的贡献。在小麦 - 玉米轮作13年和20年后，从0 - 20厘米、20 - 40厘米、40 - 60厘米、60 - 80厘米和80 - 100厘米深度采集土壤样本，并测定土壤有机碳及其稳定碳（13C）组成。我们的数据表明，土壤有机碳的δ(13)C值平均从0 - 20厘米深度的 - 22.1‰变化到80 - 100厘米深度的 - 21.5‰。通过玉米残茬输入的碳占比在35%至68%之间，而玉米残茬对0 - 40厘米深度土壤有机碳的贡献在28%至40%之间。我们的分析表明，玉米残茬的保留系数在8.0 - 13.6%范围内，小麦残茬的保留系数在16.5 - 28.5%范围内。小麦残茬的保留系数比玉米残茬高两倍，这是由于残茬质量差异以及可能生长季节温度的不同所致。我们的研究突出了作物管理对农田碳固存的重要性。