中文摘要：

采用野外采样与室内分析的方法，研究了澧阳平原杉龙岗遗址埋藏古水稻土与现代耕作水稻土铁形态、含量变化及剖面演变特征，探讨了土壤铁形态变化与成土过程的关系。结果表明：澧阳平原现代耕作水稻土与埋藏古水稻土铁形态及含量分别为：全铁31．61～35．10g／kg和33．97～46．88g／kg，游离铁8．88～13．92g／kg和11．10～20．36g／kg，无定型铁2．52～4．06g／kg和2．64～3．35g／kg，结晶态铁5．06—11．40g／kg和8．46～17．43g／kg。澧阳平原水稻土各形态铁含量除无定型铁外，其他形态铁含量总趋势为埋藏古水稻土〉现代耕作水稻土，且古水稻土各形态铁分异明显。现代耕作水稻土全铁、游离铁、结晶铁含量均呈现随深度加深而增加趋势，而无定型铁则相反，且各形态铁含量波动性较小；埋藏古水稻土全铁含量随土层增深而增加，无定型铁含量呈现微幅增加趋势，但游离铁和结晶铁含量变化有异，PA剖面减少，PC剖面增加，埋藏古水稻土中各形态铁含量变化趋势多样。澧阳平原古水稻土的铁有明显的淋溶淀积特征，不同形态铁在各土层变异较大，埋藏古水稻土铁富集明显。

英文摘要：

The field sampling and laboratory analysis were conducted to study the content changes of iron forms and their profile variations in current paddy soils and buried ancient paddy soils at Sanlonggang Village of Liyang Plain. The relationship between the changes of iron forms and soil forming process were also analyzed. The results showed that the contents of different iron forms in current and buried ancient paddy soils in Liyang Plain were： total iron 31.61-35.10 g/kg and 33.97-46.88 g/kg; free iron 8.88-13.92g/kg and 11.10-20.36g/kg; amorphous iron 2.52-4.06 g/kg and 2.64-3.35g/kg; crystal iron 5.06-11.40g/kg and 8.46-17.43g/kg, respectively. Except amorphous iron, the concentrations of other iron forms changed in the trend of ancient paddy soils 〉 current paddy soils. Obvious variations of different iron forms were observed in buried ancient paddy soils. For the current paddy soil, the contents of total iron, free iron and crystal iron increased with increasing depth, the opposite trend was found for amorphous iron, and the variations of different iron forms in the profile changed less. For buried ancient paddy soils, the content of total iron increased with increasing depth while amorphous iron increased slightly, the contents of free iron and crystal iron decreased in PA profile but increased in PC profile. The change modes of the different iron forms were diverse in the buried ancient paddy soils, obvious iron eluviation and deposition process were existed in the ancient paddy soils, the contents of different iron forms changed significantly in different horizons and the iron enrichment were obviously the buried ancient paddy soils.