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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间的差异较小。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。
Taking the five types of paddy rice in the middle and lower reaches of the Yangtze River as materials, the differences of nitrogen uptake by soils with different growth types under no-nitrogen fertilization were studied under different field conditions in order to clarify the effects of different types of paddy on soil nitrogen uptake response. The results showed that the amount of basal nitrogen supply increased with the extension of rice growth period. The late mature japonica rice was 28.99%, 18.18% and 9.27% higher than that of early maturity medium maturity medium japonica maturity middle maturity japonica rice and early maturing late japonica rice, respectively. And 6.06%, respectively, indicating that the late growth period of late japonica than the japonica rice soil nitrogen absorption capacity. Soil nitrogen utilization efficiency and soil nitrogen harvest index were consistent in the variation between Chinese and japonica cultivars, which increased firstly and then decreased with the extension of the growing period. The change trend of the late japonica rice was as follows: Increasing soil N use efficiency increased the difference between soil N harvest index types was small. Correlation analysis showed that there was a significant positive correlation between basal nitrogen supply and basic yield, and negatively correlated with soil nitrogen utilization efficiency and soil nitrogen harvest index. This shows that the basic nitrogen supply capacity of the soil determines the basic yield level, and restricts the soil nitrogen utilization efficiency and nitrogen harvest index size.