1.College of Tropical Crops, Hainan University;2.Institute of Agricultural Environment and Soil, Hainan Academy of Agricultural Sciences/Hainan Scientific Observation Station of Cultivated Land Conservation of Ministry of Agriculture and Rural Areas/Key Laboratory of Cultivated Land Conservation in Hainan Province;3.Soft X-ray Experimental Station, Institute of High Energy Physics, Chinese Academy of Sciences
Supported by the Natural Science Foundation for High-level Talents from Basic and Applied Basic Research Programs of Hainan Province, China (No. 2019RC022) and the Natural Science Foundation of Hainan Province, China (No. 322MS017)
从有机肥料中提取的溶解性有机质（DOM）可为不同的商业有机肥料的潜在应用提供新的见解。选用四种不同来源有机肥（生物质炭肥，WSB；羊粪有机肥，SM；海藻有机肥，SW；虾肽有机肥，SP）与昌化矿区周边土壤为研究材料，进行为期三个月的培养试验，采用多元光谱分析研究土壤DOM分子特征对有机肥分解的响应。与对照组相比，在培养过程中添加四种有机肥均增加土壤DOM的含量，WSB处理增加量最低，SW处理增加最高。激发发射矩阵结合平行因子分析 (EEM-PARAFAC) 表明培养过程中添加WSB提高了土壤DOM中类胡敏酸组分，减少了类富里酸组分；添加SM、SW和SP在0~45 d内降低了土壤DOM中微生物转化的类胡敏酸组分的比例而提高类富里酸组分，在45~90 d内增加难降解的类胡敏酸组分的比例。二维红外相关分析 ( 2D-FTIR-COS) 表明CK和SP处理中土壤DOM的芳香性或羧酸碳优先对分解时间发生响应；而添加WSB、SW和SM处理组中土壤DOM的烯烃或多糖类碳优先对分解时间发生响应；添加WSB和SP处理土壤提取液中也出现了Si-O-Al等土壤纳米矿物类官能团响应信号。碳近边X射线吸收精细结构 (C 1s NEXAFS) 分析结果表明：培养结束后，与未添加有机肥处理相比，WSB处理提高土壤DOM中含氧脂肪族碳组分比例，而减少芳香与酚类碳比例；SW处理主要增加了芳香碳、羰基碳的比例，而减少了脂族碳和氧烷基碳含量；SM、SP处理增加了酚类碳、芳香碳以及脂族碳比例，减少了羧基碳、氧烷基碳和羰基碳比例。本研究结果可增强对不同来源有机肥分解影响土壤DOM分子特征的了解，对于评估土壤中施用商品有机肥料的生态环境效应至关重要。
【Objective】 Dissolved organic matter (DOM) derived from organic fertilizers may provide new insights into the potential applications of different commercial organic fertilizers.【Method】Herein, four different sources of organic fertilizers (biochar, WSB; sheep manure, SM; seaweed, SW; shrimp peptide, SP) with soils around the Changhua mine site were used to carry out a three-month incubation experiment. The subsequent effect of organic fertilizer amendment on molecular characteristics of soil DOM was investigated using multivariate spectral analysis. 【Result】Compared to the control, soil DOM concentrations significantly increased in response to organic fertilizers amendment during the whole incubation period, exhibiting the lowest increment in WSB treatment and the highest increment in SW treatment, respectively. The excitation-emission matrix with parallel factor (EEM-PARAFAC) showed that WSB increased the proportion of humic-like fluorophore of soil DOM while fulvic acid-like fluorophore decreased during the whole incubation period. Also, SM, SW and SP amendments lowered the proportion of microbially-transformed humic-like fluorophore and increased the proportion of fulvic-acid like fluorophore during 0-45 days, but increased the proportion of refractory humic-like fluorophore during 45-90 days. Two-dimensional correlation spectroscopy analysis on Fourier-transform infrared (2D-FTIR-COS) spectroscopy revealed that aromatic/carboxylic acid groups of soil DOM in the control and SP treatments and alkene/polysaccharide groups in the added WSB, SW and SM treatments had the fastest responses over time, respectively. In addition, Si-O-Al signals from soil nano-minerals functional groups exhibited a distinct response over time in the added WSB and SP treatments. The carbon near-edge X-ray absorption fine structure (C 1s NEXAFS) analysis showed that compared to control, the added WSB increased the proportion of oxygenated aliphatic fractions but reduced aromatic/phenolic fractions of soil DOM after incubation. Also, SW increased the proportion of aromatic and carbonyl fractions but reduced aliphatic and oxyalkyl fractions while SM and SP increased the proportion of phenolic, aromatic and aliphatic fractions but reduced the proportion of carboxyl, oxyalkyl and carbonyl fractions. 【Conclusion】The results of this study can enhance our understanding of how the decomposition of different sources of organic fertilisers affects the molecular characteristics of soil DOM. This is essential for assessing the ecological effects of the application of commercial organic fertilisers in soils.
CHEN Liming, WU Yueying, LI Caisheng, WU Zhipeng, HUANG Cheng, JI Hengkuan, HOU Zhengwei, FU Chuanliang, ZHAO Yidong, WU Weidong. Molecular Characteristics of Soil Dissolved Organic Matter in Response to Decomposition of Organic Fertilizers from Different Sources[J]. Acta Pedologica Sinica, DOI:10.11766/trxb202111290519,[In Press]