耕作历史和种植方式是影响黑河绿洲农田土壤总有机碳及其组成的重要因素。研究结果显示,随着耕作时间的延长,土壤总有机碳(TOC)、活性有机碳(AOC)、惰性有机碳(NOC)的含量均呈增加趋势,但AOC、NOC的增幅存在差异,AOC因性质活泼,对农业活动等措施引起的变化较NOC有较快响应,因此,在耕作的初期(0~5 a),AOC的增幅高于NOC,而20 a的耕地NOC增幅大于AOC,之后达到AOC与NOC的增幅接近(>100 a)的动态发展趋势,表明总有机碳含量积累的过程是AOC与NOC增幅逐渐接近、NOC积累增速的过程。>100 a的耕地,因种植方式不同,剖面上TOC、AOC、NOC含量呈现出:油菜地>普通玉米地>制种玉米地>小麦地。分析发现,绿洲区近年来大面积种植制种玉米引起TOC、AOC、NOC发生改变,增加秸秆或牲畜粪便的归还量是提高土壤有机碳的有效途径。
Abstract
Cultivation history and cropping system are the important influencing factors of SOC and its components in the Heihe oasis, the objective of this study is to identify the effects. Soil sampling pits are selected and the space positions are determined by using the GPS instrument. The soil sampling depth of 100 cm are divided into intervals of 0-20, 20-40, 40-60, 60-80 and 80-100 cm. After soil sample preparation, total organic carbon(TOC) is measured by acid dichromate digestion and FeSO4 titration, active organic carbon(AOC) is measured by potassium permanganate oxygenation, nonactive organic carbon(NOC) is calculated as the difference between TOC and AOC. Biomass including root and crop straw is surveyed by using 1 m×1 m squares and the net weight is weighted. Cultivation history is obtained by field research. Results show the contents of TOC, AOC and NOC are increased with the extension of cultivation time, but to different degrees. AOC is faster than NOC in 0-5 years for easy transformation characters to agriculture activity after the low organic matter natural soil was converted to cotton field, then lower than NOC in 5-20 years, finally the extent of AOC is close to DOC in >100 years. This indicates NOC content significantly increased and extent of AOC and NOC is gradually close to the increase of TOC. In soil profile >100 years, the contents of TOC, AOC and NOC with the order from high to low is rape plot, general corn plot, corn plot for seed and wheat plot, respectively. Compared with annual variation of organic matter restitution in wheat and corn plots, corn plot for seed ranges between wheat plot and general corn plot. The analysis indicates planting of corn for seed causes change of TOC, AOC and NOC, and effective approach of enhancing SOC content is to increase organic matter return of straw and livestock dejection.
关键词
耕作历史 /
种植制度 /
土壤有机碳 /
黑河绿洲区
{{custom_keyword}} /
Key words
cultivation history /
cropping system /
soil organic carbon /
Heihe oasis
{{custom_keyword}} /
中图分类号:
S153.6
{{custom_clc.code}}
({{custom_clc.text}})
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] McCarl B A, Metting F B, Rice C. Soil carbon sequestration[J]. Climatic Change, 2007, 80: 1-3.
[2] 潘根兴. 中国土壤有机碳库极其演变与应对气候变化[J]. 气候变化研究进展, 2008, 4(5): 282-289.
[3] 许信旺. 不同地理尺度下农田土壤有机碳分布与变化. 南京: 南京农业大学, 2008.
[4] Lal R. Soil C sequestration in China through agricultural intensification and restoration of degraded and decertified soils [J]. Land Degradation & Development, 2002, 13: 469-478.
[5] 韩冰, 王效科, 欧阳志云. 中国农田生态系统土壤碳库的饱和水平及其固碳潜力[J]. 农村生态环境, 2005, 21(4): 6-11.
[6] 孙文娟, 黄耀, 张稳, 等. 农田土壤固碳潜力研究的关键科学问题[J]. 地球科学进展, 2008, 23(9): 996-1004.
[7] 徐万里, 唐光木, 盛建东, 等. 垦殖对新疆绿洲农田土壤有机碳组分及团聚体稳定性的影响[J]. 生态学报, 2010, 30(7): 1773-1779.
[8] Huang Y, Sun W J, Zhang W, et al. Changes in soil organic carbon of terrestrial ecosystems in China: A mini-review [J]. Science China: Life Science, 2010, 53: 766-775.
[9] 禄非, 王效科, 韩冰, 等. 农田土壤固碳措施的温室气体泄露和净减排潜力[J]. 生态学报, 2009, 29(9): 4993-5006.
[10] 王根绪, 马海燕, 王一博, 等. 黑河流域中游土地利用变化的环境影响[J]. 冰川冻土, 2003, 25(4): 359-367.
[11] 颉鹏, 蔺海明, 黄高宝, 等. 河西绿洲农田生态系统碳源/汇的时空差异研究[J]. 草业学报, 2009, 18(4): 224-229.
[12] 刘文杰, 苏永中, 杨荣, 等. 黑河中游临泽绿洲农田土壤有机质时空变化特征[J]. 干旱区地理, 2010, 33(2): 170-176.
[13] 许文强, 罗格平, 陈曦, 等. 天山北坡绿洲土壤有机碳和养分时空变异特征[J]. 地理研究, 2006, 25(6): 1013-1021.
[14] 苏永中, 刘文杰, 杨荣, 等. 河西走廊中段绿洲退化土地退耕种植苜蓿的固碳效应[J]. 生态学报, 2009, 29(12): 6385-6391.
[15] 张俊华, 李国栋, 南忠仁, 等. 黑河中游不同土地利用类型下土壤有机碳时空分布[J]. 兰州大学学报: 自然科学版, 2009, 45(4): 66-72.
[16] 王根绪, 杨玲媛, 陈玲, 等. 黑河流域土地利用变化对地下水资源的影响[J]. 地理学报, 2005, 60(3): 456-466.
[17] 霍亚贞, 李天杰. 土壤地理实验实习[M]. 北京: 高等教育出版社, 1986: 19-23.
[18] Loginow W, Wisniweski W, Strong W M, et al. Fractionation of organic carbon based on susceptibility to oxidation [J]. Polish Journal of Soil Science, 1987, 20(1): 47-52.
[19] 王周琼, 李述刚, 程心俊. 荒漠绿洲农田生态系统中养分循环[M]北京: 科学出版社, 2002: 52-160.
[20] 中国农机学会农机化学会科技交流中心. 农作物秸秆利用技术与设备[M]. 北京: 中国农业出版社, 1996: 67-70.
[21] 许信旺, 潘根兴, 汪艳林, 等. 中国农田耕层土壤有机碳变化特征及控制因素[J]. 地理研究, 2009, 28(3): 601-612.
[22] 周萍, 潘根兴, 李恋卿, 等. 南方典型水稻田长期试验下有机碳积累机制V. 碳输入与土壤碳固定[J]. 中国农业科学, 2009, 42(12): 4260-4268.
[23] Qin Z C, Huang Y. Quantification of soil organic carbon sequestration potential in cropland: A model approach [J]. Science China: Life Science, 2010, 53: 868-884.
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}
基金
国家自然科学基金(41101088);中科院知识创新重大项目(KZCX1-09);广东高校优秀青年创新人才培育项目(LYM10080)。
{{custom_fund}}