论文部分内容阅读
耕作红壤改水田6年中,磁化率逐年下降,平均下降速率为5×10~(-6)CGSM/g,3种稻作制的下降速率差异不大,绿肥处理对土壤磁化率有较大影响,用量愈大,磁化率波动幅度愈大,不施绿肥的处理则一直平缓下降,6年后不施绿肥处理土壤磁化率高于施绿肥处理,不同地下水位对植稻土壤表层(0～20cm)磁化率影响很小,而对底层(20～40cm)影响大。磁化率动态和无定形铁有负相关性,而和游离铁之间相关性差,不同绿肥用量及不同地下水位处理6年后磁化率和无定形铁及铁活化度之间反相关明显,植稻6年后土壤磁化率为稻地同母质老水稻土的8倍,比幼年水稻土也高得多,估计红壤旱改水后至少连续种植10年以上才能形成幼年水稻土,结合其它性状考察,磁化率可能作为鉴定水稻土的重要指标之一。
During the six years of farming and red soil improvement, the magnetic susceptibility decreased year by year with an average rate of 5 × 10 -6 CGSM / g. There was no significant difference in the rate of decline among the three rice systems, The higher the amount of magnetic susceptibility, the greater the fluctuation of magnetic susceptibility. The treatment without applying green manure decreased gently. After 6 years, the magnetic susceptibility of the soil without applying green manure was higher than that with green manure. 20cm) magnetic susceptibility little effect, while the bottom (20 ~ 40cm) big impact. There was a negative correlation between magnetic susceptibility and amorphous iron. However, there was a negative correlation between magnetic susceptibility and amorphous iron and iron activation after 6 years of treatment with different amounts of green manure and different groundwater levels. After six years, the soil magnetic susceptibility is eight times that of the parent paddy soil, which is much higher than that of the young paddy soil. It is estimated that the red soil can be planted for at least 10 years after it has been drought-reformed for a minimum of ten years to form the juvenile paddy soil. Combined with other traits, Magnetic susceptibility may be used as an important indicator of paddy soil identification.