摘要
【目的】土壤有机质是衡量土壤肥力的重要指标,是农林生态系统中植物速效养分的源泉,对生产力的高低及其稳定性有决定性作用,而有机质的分解速率与其化学结构密切相关。因此对有机质化学结构进行表征和量化估算,对充分认识有机质的转化循环具有重要意义。【方法】为探究种植年限及土层深度对有机质含量及其官能团含量的影响,探讨不同种植年限下有机质结构稳定性的差异。文章以不同种植年限(5,10,20,40 a)甜龙竹林土壤为研究对象,采用傅里叶红外光谱对林下土壤有机质(SOM)结构进行表征及半定量分析。【结果】(1)随着种植年限的延长,有机质含量增加,种植年限为10、20、40 a有机质含量显著高于5 a。(2)不同种植年限有机质官能团种类一致,主要为:来源于糖类(1011+1031+1089)cm-1、芳香族(1634)cm-1、脂肪族(2858+2925)cm-1、醇酚(3445+3621+3694)cm-1,但不同种植年限下各特征峰拟合面积和相对强度差异显著,40 a比5 a的甜龙竹林土壤有机质糖类、芳香族、脂肪族化合物特征峰拟合面积分别提高58.56%、29.56%、9.50%,酚醇下降47.83%,特征峰相对强度分别提高54.37%、24.66%、8.42%,醇酚物质相对峰强度下降47.09%。(3)有机质稳定性随着种植年限的延长,0~20 cm、20~40 cm和40~60 cm 3层土壤稳定性逐渐趋于一致,说明长期种植甜龙竹有利于化学结构复杂、难分解物质积累进入深层土。【结论】甜龙竹种植年限延长有利于土壤有机质含量积累,并使有机质结构趋于芳香化、脂肪化,增加糖类化合物含量,提高有机质化学结构稳定性。
Objective]Soil organic matter is an important index to measure soil fertility and the source of plant available nutrients in the agroforestry ecosystem.It plays a decisive role in the level and stability of productivity,and the decomposition rate of organic matter is closely related to its chemical structure.Therefore,the characterization and quantitative estimation of the chemical structure of organic matter are of great significance to fully understand the transformation cycle of organic matter.[Methods]In order to explore the effects of planting durations and soil depth on the content of organic matter and its functional groups,as well as the differences of structural stability of organic matter under different planting durations,the structure of soil organic matter(SOM)under D.brandisii forest with different planting durations(5,10,20,40 a)was semi-quantitatively analyzed by Fourier infrared spectroscopy.[Results]This study found that:(1)with the extension of planting durations,the content of organic matter increased,and the content of organic matter in 10 a,20 a and 40 a was significantly higher than that in 5 a.(2)The functional groups of organic matter in different planting durations were the same,mainly including sugars(1 011+1 031+1 089)cm-1,aromatic(1 634)cm-1,aliphatic(2 858+2 925)cm-1,alcohols and phenols(3 445+3 621+3 694)cm-1,but the fitting area and relative intensity of each characteristic peak were significantly different under different planting durations.The fitting areas of characteristic peaks of sugars,aromatic and aliphatic compounds in soil organic matter of D.brandisii forest in 40a were 58.56%,29.56%and 9.50%higher than those of 5 a,phenols and alcohols were 47.83%lower,and the relative intensity of characteristic peaks was 54.37%,24.66%and 8.42%higher,the relative peak intensity of alcohols and phenols decreased by 47.09%.(3)With the extension of planting durations,the stability of organic matter in the three layers of 0-20 cm,20-40 cm and 40-60 cm gradually tended to be consistent,indicating that the longterm planting of D.brandisii was conducive to the accumulation of complex chemical structure and refractory substances into the deep soil.[Conclusion]The extension of planting durations of D.brandisii is beneficial to the accumulation of organic matter content,the aromatization and fatty structure of soil organic matter,the increase of carbohydrate content and the stability of organic matter chemical structure.
作者
赵秀婷
辉朝茂
朱书红
刘蔚漪
蔡春丽
张文君
涂丹丹
朱礼月
ZHAO Xiuting;HUI Chaomao;ZHU Shuhong;LIU Weiyi;CAI Chunli;Zhang Wenjun;Tu Dandan;Zhu Liyue(College of Foresty,Institute of Bamboo and Rattan/Engineering Research Center of Sympodial Bamboo,Southwest Forestry University,Kunming 650224,China)
出处
《江西农业大学学报》
CAS
CSCD
北大核心
2022年第6期1448-1456,共9页
Acta Agriculturae Universitatis Jiangxiensis
基金
国家重点研发计划项目(2021YFD2200501)
云南省基础研究专项(202201AT070053)。
关键词
甜龙竹
种植年限
土壤有机质
官能团
红外光谱
Dendrocalamus brandisii
planting durations
soil organic matter
functional groups
infrared spectrum
