中文摘要：

以湖南农业大学1982年设置的长期定位试验为研究对象，研究了水稻生育期间红壤性水稻土有效锰含量的动态变化。结果表明：水稻生育期间，土壤交换性锰和易还原态锰含量在不断地发生变化。早稻生育期间，插秧前土壤交换性锰含量最高，随着水稻生育进展，含量逐渐下降；而土壤易还原态锰含量插秧前最低，随着水稻生育进展，含量逐渐升高。晚稻生育期间，从插秧前到孕穗期，交换性锰含量逐渐升高，到孕穗期达到最高，之后到黄熟期，交换性锰含量又逐渐降低；而易还原态锰含量则从插秧前到孕穗期逐渐降低，到孕穗期达到最低值，之后，又升高。不同稻作制对土壤交换性锰和易还原态锰含量的影响差异最大，稻-稻-冬泡处理土壤交换性锰和易还原态锰含量明显高于稻-稻-冬绿和稻-稻-冬油两种水旱轮作处理。

英文摘要：

The effects of 3 rice-based cropping systems, 3 application rates of organic manure and 2 groundwater levels on dynamic changes of available Mn during rice growth in 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：During rice growth, contents of eq~changeable Mn and easily reducible Mn in the paddy soil changed constantly. In the early rice growth period, content of exchangeable Mn was maximum before, and it decreased gradually with early rice growth stages; while content of easily reducible Mn was minimum before transplanting, and it increased gradually with early rice growth stages. In late rice growth period, content of exchangeable Mn increased with late rice growth stages from transplanting to panicle formation and reached maximum; thereafter exchangeable Mn decreased until mature period. The content of easily reducible Mn decreased with late rice growth stages from transplanting to panicle formation, and reached minimum at panicle formation; thereafter easily reducible Mn content decreased with late rice growth stages. Effects office-based cropping systems on exchangeable Mn and easily reducible Mn were still maximum, exchangeable Mn and easily reducible Mn contents in the soil treated with ＂early rice-late rice-flooded follow in winter＂ were evidently higher than those of the treatments of ＂early rice- late rice-green manure crop in winter＂ and ＂early rice-late rice- oilseed rape in winter＂.