【摘要】 为探明土壤固定态铵在作物生育期间的动态变化及在水稻氮素营养中的贡献,为作物的合理施肥提供依据,采用盆栽试验和Silva-Bremner法,研究了3种土壤条件下水稻生育期间固定态铵的动态变化及其释放情况.结果表明,水稻生育期间,稻田土壤固定态铵含量处于不断变化之中,施氮肥能促进土壤对铵的矿物固定,水稻生长和对养分的吸收则促进土壤固定态铵的释放.早稻生育期间土壤固定态铵含量变幅较小,且释放不多,除黄泥田的CK处理外,仅有“新固定的”固定态铵释放,其释放量占“新固定的”固定态铵量的18.8%～100%;而晚稻生育期间土壤固定态铵含量变幅较大,且释放较多,不仅有“新固定的”固定态铵的释放,而且“原有的”固定态铵也有部分释放,其释放量为“原有的”固定态铵的2.0%～17.7%.各处理早稻和晚稻吸氮总量与产量呈极显著正相关;晚稻吸氮总量与土壤固定态铵的释放量呈显著正相关.更多还原

【Abstract】 The results of pot experiment showed that fixed ammonium contents in the paddy soils changed constantly during rice growth due to fertilization and rice growth.Application of N fertilizer could promote the ammonium fixation,while rice growth promoted release of fixed ammonium.During early rice growth,fixed ammonium changed very gently and only 18.8%～100% of recently fixed ammonium released but with the exception that under CK treatment of yellow clayey soil.But during late rice growth,fixed ammonium changed dramatically.Not only did most of the recently fixed ammonium release but inherently fixed ammonium also released partly too,and its release amount accounted for 2.0%～ 17.7% of the native fixed ammonium content.The total N uptake were significantly positively correlated with rice grain yield in every treatment of early rice growth and late rice growth mature periods.There were also positive correlation between the net release rates of fixed ammonium in soil and N uptake by rice plant during the late rice growth.更多还原