中文摘要：

以湖南农业大学1982年布置的长期定位试验为研究对象，研究了红壤旱地改水田后不同稻作制、地下水深度和有机肥施用量对土壤全锰、有效锰及其化学形态变化的影响。结果表明，与原始红壤旱土相比，红壤性水稻土耕层土壤全锰、氧化锰和有效锰总量明显下降，但易溶态锰含量明显升高。稻作制对土壤锰的化学行为和有效性的影响最明显，稻-稻-冬泡处理的土壤全锰和各形态有效锰含量均明显大于稻-稻-冬绿和稻-稻-冬油处理，且不同处理之间各形态有效锰含量差异达1％的极显著水平，说明水旱轮作在一定程度上造成土壤锰的淋溶损失较持续淹水更为严重。有机肥处理土壤全锰含量均高于化肥处理，且常量有机肥和化肥处理之间全锰含量差异达1％的极显著水平，但化肥处理的各形态有效锰含量均大于有机肥处理。不同地下水位深度处理对土壤全锰和各形态氧化锰含量影响的差异不显著。

英文摘要：

The effects of 3 rice-based cropping systems, 3 application rates of organic manure and 2 groundwater levels on total Mn, available Mn and its chemical fractions of the paddy soil reclaimed from cultivated red soil were studied based on the long-term stationary experiment of Hunan agriculture university. The main results are as follows： Compared to the original upland soil, the contents of total Mn, oxide Mn and available Mn in the plough laver of paddy soil reclaimed from red earth were significantly decreased, but contents of readily soluble Mn increased evidently. For different rice-based cropping systems, application rates of organic manure and groundwater levels,the rice-based cropping systems had strongest effects on chemical fractions and availability of Mn in soil. the contents of total Mn and various chemical fractions of available Mn of the soil with ＂early rice-late rice-flooded follow in winter＂ treatment were higher than that of the soil with the treatments of ＂early rice-late rice-green manure in winter＂ and ＂early rice-late rice-oilseed rape in winter＂. Analysis of variance showed that the difference in contents of various chemical fractions of available Mn between different treatments reached the significant level of 1% . It indicated that Mn leaching was more severe under alternation of wetting and drying as compared with continuous flooding to certain extent. For the treatments of different application rates of organic manure, the contents of total Mn in both ＂normal rate of organic manure＂ and ＂ high-rate of organic manure ＂ treatments were higher than that in＂chemical fertilizer＂ treatment. Analysis of variance showed that the difference in contents of total Mn in soils between treatment of＂ normal rate of organic manure＂ and ＂ chemical fertilizer＂ reached the significant level of 1%, while the contents of various chemical fractions of available Mn in the soil treated with ＂chemical fertilizer＂ were higher than that of treatments of＂ normal rate of organ