植稻年限对土壤铁锰氧化物的影响

Influences of Rice-Planting Duration on Iron and Manganese Oxides in Paddy Soils

以浙江不同耕作年限水田和旱地为研究对象,探讨了植稻年限对土壤铁锰氧化物的影响,并揭示了水稻土发育过程中铁锰氧化物的剖面运移规律和诊断意义。结果表明:①土壤剖面中,全Fe、游离Fe及全Mn的变异随着种稻时间的延长而增大。种植达到一定年限时,全Fe、全Mn以及游离Fe在土壤剖面下层出现淀积。在各种铁锰氧化物中,对水稻土最具诊断意义的是游离Fe和全Fe。②无定形Fe以及络合态Fe、Mn与有机质呈显著正相关。植稻年限对它们的影响是通过对有机质的影响达到的。

The influences of rice-planting duration on iron and manganese oxides were studied by using paddy soils and dry lands in Zhejiang of different planting chronosequence. The results revealed the migration regularities of iron and manganese oxides in soil profiles and the diagnostic significance during the formation of paddy soil. The variations of total iron, free iron oxide and total manganese increased with the increase of rice-planting duration. Total iron, total manganese and free iron oxide accumulated at the low layers after a certain years of rice planting. Among the iron and manganese oxides, free oxide and total iron were the most significantly diagnostic factors for the classification of paddy soil. Amorphous, complex iron and complex manganese were significantly positively correlated with organic matter content, thus, the influences of rice-planting duration on amorphous iron and complex iron could be considered to recur to the role of organic materials.