Abstract: Upland rice cultivar Zhonghan 3(japonica)and paddy rice cultivar Wuxiangjing 99-8 (japonica) were used to study the effects of cultivation methods on nitrogen(N) absorption and use efficiency at later growth stage. The rice grain yield was significantly lower under dry cultivation than under submerged cultivation(SC,control) for Zhonghan 3 and there was no significant difference between dry cultivation with plastic film mulching (PFMC) and MC for Wuxiangjing 99-8,and the yield was the lowest under bare cultivation(BC)among the three cultivation methods for two cultivars. N contents in the plants under PFMC and BC were lower at heading,and decreased more slowly from heading to maturity with the order of SC > BC >PFMC. The amount of N absorption by plants was in the order of SC > PFMC > BC at heading and maturity. The proportion of N was significantly higher in the culms and sheaths,whereas significantly lower in the grains,under dry cultivation than under SC. The proportion of N in leaves was different between the two cultivars. N efficiency of matter production was significantly greater under dry cultivation than under SC at heading and was the least for PFMC among the three cultivation methods at maturity. Dry cultivation had higher N efficiency of grain yield production(except PFMC for Zhonghan 3)and greater N harvest index than SC,with the order of BC > PFMC > SC. Compared with Wuxiangjing 99-8,Zhonghan 3 exhibited a faster decrease in N content after heading,smaller N accumulation in plants,greater proportion of N in leaves and grains and smaller in the culms and sheaths,higher N efficiency of matter production(at maturity) and grain yield production,greater N harvest index,and lower grain yield.

Key words: upland rice, paddy rice, nitrogen, absorption and use efficiency, rice dry cultivation

摘要： 以武香粳99-8（水稻）和中旱3号（陆稻）为材料，研究了种植方式对水稻和陆稻生育后期N素吸收利用的影响。与水种稻（对照）相比，中旱3号覆膜旱种时产量显著低于对照，武香粳99-8覆膜旱种时和对照没有显著差异，裸地旱种产量均为最低。覆膜旱种和裸地旱种抽穗期植株的含N率较低，抽穗至成熟期植株含N率下降速率为水种＞裸地旱种＞覆膜旱种。抽穗和成熟期植株吸N量大小为水种＞覆膜旱种＞裸地旱种。旱种稻成熟期茎鞘中的N素分配显著高于对照，籽粒显著低于对照，品种间叶片有所不同。抽穗期旱种稻的N素物质生产效率显著高于对照。成熟期覆膜旱种N素物质生产效率最低。旱种稻N素籽粒生产效率（中旱3号覆膜旱种除外）和N素收获指数较对照增加，大小为裸地旱种＞覆膜旱种＞水种。与武香粳99-8相比，中旱3号抽穗后植株含N率下降快，植株N素积累量较小，叶片和籽粒中N素分配比例高，茎鞘低；N素物质生产效率（成熟期）、N素籽粒生产效率和N素收获指数高，产量低。

关键词: 陆稻, 水稻, 氮素, 吸收利用效率, 水稻旱作