不同耕作措施对黑土腐殖酸组成与红外光谱特性的影响

选择公主岭市范家屯长达10年的耕作处理试验地，采集了不同耕作处理模式下的土壤样品，利用元素分析、可见光谱、红外光谱分析了不同处理对黑土的0～20 cm HA结构的影响。结果表明：旋耕深松、宽窄行交替休闲处理下HA的N/C，H/C，O/C值明显高于翻耕垄作、旋耕垄作处理;翻耕垄作处理下0～20 cm土壤胡敏酸E₄/E₆值最小，芳构化程度高;而宽窄行交替休闲处理下0～20 cm土壤胡敏酸的E₄/E₆值最大，其芳化度最低;旋耕深松和旋耕垄作下表层0～20 cm土壤胡敏酸的E₄/E₆值相同，与翻耕处理相比其芳化度有所降低;红外光谱吸收峰分析表明，翻耕处理下表层土壤胡敏酸中杂环氮的数量增加，宽窄行交替休闲处理下表层土壤胡敏酸结构中的含氮化合物数量、脂肪族化合物数量增加，而旋耕垄作处理增加了表层土壤胡敏酸结构中的OH基、脂肪族的CH₂官能团、氨基化合物含量;旋耕深松、翻耕垄作处理增加其表层胡敏酸结构中的CO基及C—O基数量。

Effect of Different Tillage Managements on Black Humic Fractions and IR Spectral Feature

The present study was based on the long-term (10 years) field conservation tillage experiment, in which four tillage treatments were designed as following： Conventional tillage (CT) by moldboard plowing with ridge culture; Rotary tillage with ridge culture (RT) ; Alternant tillage by rotary on wide row and loosing on narrow row (WN) ; Rotary tillage plus deep loosing annually (RD). Humic acids were extracted from black soil profiles under these tillage managements. The elements visible spectra and FTIR of HA in black soil were analyzed. The results indicated that the elements of HA were affected by different tillage managements, WN increased N/C, H/C and O/C values of HA in the 0-20 cm layer. The lowest E4/E6 value of HA was found under CT treatment, while the highest E4/E6 value was found under WN treatment; FTIR indicated that CT treatment increased the amount of C=N groups and aromatic ring condensation of HA in 0-20 cm soil, while WN decreased aromatic ring condensation and increased the content of nitrogen compound and aliphatic compound. RT increased the functional groups of OH, aliphatie CH2 and nitrogen compound. CT and RD increased the content of C=O and C=O.