江西农业大学学报2023，Vol.45Issue(6)：1575-1587,13.DOI:10.13836/j.jjau.2023143
不同种植年限红壤柑橘园土壤腐殖质化学组成和结构特征差异
Differences in Chemical Composition and Structural Characteristics of Soil Humus along Different Cultivation Chronosequence of Citrus Orchards
摘要
Abstract
[Objective]Long-term monitoring the chemical composition and molecular structure of soil organic carbon in orchards is helpful in understanding the responses of orchard soil carbon sequestration and sink enhancement function to human cultivation activities,thus providing theoretical basis for agricultural carbon sequestration and emission reduction,and achievement of the double carbon goal.[Method]The long-term planted red soil citrus orchard was taken as the research area.The surface soils(0-20 cm)of citrus orchards with different cultivation chronosequence(10,30,and 50 years)were collected.Humic acid(HA)fractions(F1-F10),and HuL and HuH fractions from humus were isolated and purified.Besides,elemental analysis,FTIR and CP/TOSS 13C-NMR were used to analyze comprehensively the content and structure changes of HA,HuL and HuH under different cultivation chronosequence.[Result](1)Chemical composition:HA fraction and humin element composition is dominated by C and O.With the extension of planting age,the C content increased(except F9-F10),The C content of F1-F2,F3-F8,HuL and HuH in soils with 50 planting years increased by 36.1%,38.34%,61.69%and 72.25%,compared with soils with 10 planting years;With the extension of planting age,F1-F2 and F3-F8 fractions of HA decreased by 40.84%and 44.33%,respectively,while HuH and HuL increased by 62.33%and 42.55%.The longer the planting period,the more favorable it was for the formation of nitrogen-containing groups of HA and less favorable for the formation of nitrogen-containing groups of humin.The aliphaticity of F1-F2,F3-F8,and F9-F10 increased by 12.8%,5.7%,and 6.6%respectively,and the aromaticity decreased by the corresponding proportions.The aliphaticity of HuH and HuL decreased by 7.2%and 0.9%,and the aromaticity increased correspondingly.With the extension of planting years,the aromatic carbon content of HA fractions decreased by 10.9%,5.38%and 3.83%,respectively,while that of HuL and HuH increased by 2.59%and 5.68%.(2)Structural characteristics:the infrared spectral peaks and positions of humus fractions with different planting ages were similar,but the absorption intensity was different.The structure of HuH was similar to that of HA,but the structure of HuL was simpler,and the C-skeleton remained unchanged.The H/C,F1-F2,F3-F8 fractions of HA decreased by 30.03%and 16.16%with the extension of planting years.With the extension of planting years,the chemical structure of HA was gradually dominated by aromatic structure,and the degree of unsaturation and aromaticity were higher.[Conclusion]The chemical composition,corresponding structural units,number of functional groups,and proportion of organic carbon of different humus components in citrus orchard soil would change with the planting years,and the soil organic carbon content would increase year by year.Continuous planting of citrus is beneficial for the stability of soil humus structure,thereby enhancing soil carbon sequestration capacity.关键词
种植年限/腐殖质组分/元素分析/红外光谱/固态13C核磁共振Key words
planting age/cultivation chronosequence/elemental analysis/FTIR/CP/TOSS 13C-NMR分类
农业科技引用本文复制引用
张雅雯,刘灿,郭新春,郑太辉..不同种植年限红壤柑橘园土壤腐殖质化学组成和结构特征差异[J].江西农业大学学报,2023,45(6):1575-1587,13.基金项目
国家自然科学基金项目(42167047)和江西省自然科学基金项目(20202BABL203029) Project supported by National Natural Science Foundation of China(42167047)and Jiangxi Natural Science Foun-dation Project(20202BABL203029) 2022年度井冈山农高区省级科技专项"揭榜挂帅"子课题(20222-051261-2-4)同时对本研究给予了资助,谨致谢意! （42167047）
