不同生育期类型水稻对稻田土壤基础供氮量的响应

以长江中下游地区5种生育期类型水稻为材料,于大田条件下研究了不施氮肥水平下不同生育类型水稻对土壤氮吸收的差异.以明确不同生育类型水稻对稻田土壤基础供氮能力的响应.结果表明,土壤基础供氮量随着水稻生育期的延长而增加,中熟晚粳分别比早熟中粳、中熟中粳、迟熟中粳和早熟晚粳高28.99%,18.18%,9.27%和6.06%,表明生育期长的晚粳较中粳对土壤氮素的吸收能力强.土壤氮素利用效率和土壤氮素收获指数,在中粳间的变化规律一致,即随生育期的延长呈先增加后降低的趋势;在晚粳间的变化趋势则表现为,随生育期的延长土壤氮素利用效率增加,土壤氮素收获指数类型问的差异较小.相关分析表明,土壤基础供氮量与基础产量呈极显著的正相关关系,与土壤氮素利用效率和土壤氮素收获指数呈显著或极显著负相关关系.说明土壤基础供氮能力的高低决定着基础产量水平,同时制约着土壤氮素利用效率和氮素收获指数的大小.

Response of Different Growth Duration Type Rice to the Paddy Field Soil Basal Nitrogen Supply

A field experiment was conducted with early(125～135d),medium(136～145 d)and late-maturing (146～155 d)medium japoniea and early(156～165 d)and medium-maturing(166～175 d)late Japonica rice under zero N fertilizer in 2006 and 2007 Soil N absorption was analyzed in order to explore the response of five growth duration types rice to the soil basal nitrogen supply.The results showed that soil basal N accumulation increased with the rice growth duration prolonging.Soil basal N accumulation of medium-maturing late Japonica rice was 28.99%,18.18%,9.27%and 6.06% higher than early,medium and late-maturing middle Japonica rice and early-maturing late Japonica rice respectively,which indicated that late-maturing Japonica rice was more intensively to soil basal N accumulation than middle-maturing Japonica rice. N use efficiency of soil and son N harvest index in middle Japonica rice tended to increase firstly,then declined with the growth duration prolonging,while N use efficiency of soil increased,and soil N harvest index was little differences in late Japonica rice.Correlation analysis showed that there existed significant highly positive correlation between soil basal N accumulation and basal yield,and significant or highly significant negative correlations between soil basal N accumulation and N use efficiency of soil,soil N harvest index.It indicated that the capacity of soil basal N supply determined the level of basal yield and limited N use efficiency of soil and soil N harvest index at the same time.