添加秸秆、生物质炭对陇中黄土高原旱作农田土壤溶解性有机碳的影响  

Effects of adding straw and biochar on soil dissolved organic carbon in dryland farming of the Loess Plateau in central Gansu

作　　者：龚丽娟 武均[1,2] 齐鹏[1,2] GONG Li-juan;WU Jun;QI Peng(College of Resources and Environmental Sciences,Gansu Agricultural University,Lanzhou Gansu 730070;Gansu Provincial Key Laboratory of Arid Land Crop Science,Gansu Agricultural University,Lanzhou Gansu 730070)

机构地区：[1]甘肃农业大学资源与环境学院,甘肃兰州730070 [2]甘肃农业大学甘肃省干旱生境作物学重点实验室,甘肃兰州730070

出　　处：《中国土壤与肥料》2025年第2期31-42,共12页Soil and Fertilizer Sciences in China

基　　金：甘肃省自然科学基金(20JR10RA543);甘肃农业大学公招博士科研启动基金(GAU-KYQD-2018-39)。

摘　　要：以2021年布设于甘肃省定西市李家堡镇的有机物料施用模式田间定位试验为研究对象,利用紫外-可见光谱技术,探索了单施生物质炭(B)、秸秆还田(S)、生物质炭配施秸秆(BS)、1次添加4年生物质炭(B4)、常规施肥(CK)5种有机物料添加模式下陇中旱作农田2022和2023年土壤溶解性有机碳(DOC)的紫外-可见光光谱特征。结果表明:添加秸秆与生物质炭能显著增加DOC含量,且S处理下的DOC含量更高,较CK处理显著提升了141.90%~223.79%。秸秆与生物质炭添加处理均可显著增加有色溶解性有机物[以α(355)表征]的含量,B处理效果最优,较CK处理显著提升了191.22%~244.10%。添加秸秆与生物质炭后DOC的光谱吸收值SUVA254、SUVA260和SUVA280均有所增加,但S处理效果不显著;添加有机物料可降低光谱吸收比E2/E3、E3/E4、E4/E6,S处理下降趋势最显著。CK处理与B、S、BS、B4处理10~30 cm土层DOC的E3/E4值均大于3.5,表明土壤中DOC以富里酸为主,而B、S、BS、B4处理0~10cm土层DOC的E3/E4值小于3.5,表明其土壤中DOC以胡敏酸为主。综上所述,S处理对DOC含量及腐殖化的提升效果最优,BS处理对DOC分子的芳香性、疏水性及分子量提升效果最佳。The Ultraviolet Visible spectroscopic characteristics of soil dissolved organic carbon(DOC)in Central Gansu dryland soil in 2022 and 2023 were investigated in a field trial conducted in Lijiabu township,Dingxi city,Gansu province in 2021 using Ultraviolet Visible spectroscopy.Five treatments were set up,including single application of biochar(B),returning straw to the field(S),combined application of biochar and straw(BS),one-time addition of 4-year biochar(B4),conventional fertilization(CK).The results showed that the addition of straw and biomass charcoal significantly increased the DOC content,and the DOC content was higher in the S treatment,which was 141.90%-223.79%higher than that in the CK treatment.Both straw and biomass charcoal addition treatments significantly increased the content of coloured dissolved organic matter[characterized byα(355)],and the B treatment was the most effective,with a significant increase of 191.22%-244.10%compared to the CK treatment.The spectral absorption value SUVA254,SUVA260 and SUVA280 of DOC increased with the addition of straw and biomass charcoal,but the effect of S treatment was not significant;the addition of organic materials decreased spectral absorption ratio E2/E3,E3/E4,E4/E6,and the decreasing trend was most significant in S treatment.The E3/E4 values of DOC in the 10-30 cm soil layer of the CK treatment and the B,S,BS and B4 treatments were all greater than 3.5,indicating that the soil DOC was mainly dominated by fulvic acid,while the E3/E4 values of DOC in the 0-10 cm soil layer of the B,S,BS and B4 treatments were less than 3.5,indicating that their soil DOC was mainly dominated by humic acid.In summary,the S treatment had the best effect on the improvement of DOC content and humification,and the BS treatment had the best effect on the improvement of aromaticity,hydrophobicity and molecular weight of DOC molecules.

关 键 词：秸秆还田 生物质炭 溶解性有机碳 紫外-可见光谱 

分 类 号：S153.6[农业科学—土壤学]