不同耕作制下水田土壤有机质氧化铁含量的研究

以第四纪红色粘土发育的旱土为供试土壤,淹水种稻,进行水田耕作制模拟试验,研究对土壤有机质、氧化铁含量的影响。结果表明:有机质的增加是冬泡区>冬绿区>冬油区,但只施化肥的冬泡区有机质增加量少;无定形铁的含量及氧化铁的活化度均逐年增加,其增加速度是冬泡区>冬绿区>冬油区:无定形铁含量与有机质含量之间存在一定的相关性。

ORGANIC MATTER AND IRON OXIDE STATUS OF FLOODED PADDY SOIL UNDER DIFFERENT CROPPING SYSTEMS

The experiment was conducted on a plot with arable red soil ori-ginated from quarternary red clay to simulate three main rice-based cropping systems, which were common in Hunan province, and to study their effect on the status of soil organic matter and iron oxide species. The three systems in order of increasing organic matter were winter rape, winter green manure and winter flooding but winter flooding increased organic matter slightly if only chemical fertiliger was applied. The increases of amorphous iron oxide content and the activation of iron oxide in the three systems were in the same order. There was correlation to some extent between soil amorphous iron oxide and organic matter content.