| 红壤区不同肥力水稻土根际硝化作用特征 |
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| 引用本文： | 李奕林,王兴祥. 红壤区不同肥力水稻土根际硝化作用特征[J]. 土壤学报, 2012, 49(5): 962-970 |
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| 作者姓名： | 李奕林 王兴祥 |
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| 作者单位： | 中国科学院土壤环境与污染修复重点实验室,南京土壤研究所,南京 210008 |
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| 基金项目： | 国家自然科学基金项目（面上项目，重点项目，重大项目）;中国科学院知识创新项目 |
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| 摘 要： | 通过根际培养箱(三室)——速冻切片技术研究了红壤地区高、低两种肥力下水稻苗期根表、根际和土体土壤矿质态氮含量和硝化强度,以及水稻生长、氮素积累的差异。结果表明,肥力水平对水稻根表和根际土壤铵态氮(NH4+-N)含量无显著影响,但高肥力显著提高土体土壤NH4+-N含量,以及根表、根际和土体土壤硝态氮(NO3--N)含量及硝化强度。两种肥力水稻土硝化强度最大值均出现在距根表2 mm处,分别为0.20和0.31μmol kg-1 h-1。土体土壤硝化强度随距根表距离增加而降低,低肥力土壤在距根表10～40mm处时硝化强度接近本底值,而高肥力土壤在距根表20～40 mm处时接近本底值。与不种水稻的CK相比,种植水稻显著提高根际土壤硝化强度。高肥力能显著改善水稻生长,增加植株氮素积累量,尤其显著促进根系生长及通气组织发育。由于红壤稻田肥力水平的差异造成水稻根际硝化强度以及水稻吸收NO3-的差异,导致高肥条件下水稻显示出更强的生长势和氮素吸收利用能力。因此,合理提高红壤稻田肥力水平对改善红壤区水稻根际土壤硝化作用及水稻氮素营养具有重要意义。
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| 关 键 词： | 水稻土 肥力 水稻 根际 硝化作用 |
| 收稿时间： | 2011-10-12 |
| 修稿时间： | 2012-01-06 |
Nitrification in rhizosphere of rice in paddy soils different in fertility in red soil regions of subtropical China |
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| Li Yilin and Wang Xingxiang. Nitrification in rhizosphere of rice in paddy soils different in fertility in red soil regions of subtropical China[J]. Acta Pedologica Sinica, 2012, 49(5): 962-970 |
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| Authors: | Li Yilin and Wang Xingxiang |
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| Affiliation: | Institute of Soil Science, Chinese Academy of Sciences,Institute of Soil Science, Chinese Academy of Sciences |
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| Abstract: | Differences between two paddy soils, high and low in soil fertility in the red soil region were explored in content of mineral N (NH4 and NO3-) and nitrification intensity at the root surface and rhizosphere of rice and in the bulk soil, as well as in growth and N accumulation of rice seedlings at 40, 50 and 60 d after sowing. Results show that soil fertility had no significant effect on NH4 -N content at the root surface and rhizosphere of rice, while high fertility significantly increased NH4 -N content in the bulk soil, and NO3--N contents and nitrification intensity at the root surface and rhizosphere of rice and in the bulk soil, as well. The highest nitrification intensity was observed at 2 mm away from the root surface in both soils, being 0.20 and 0.31 ?mol kg-1 h-1 in the low and high fertility soils, respectively. Nitrification intensity in the bulk soil decreased with the increasing distance from the root surface, and approximated to the background value at 10 ~ 40 mm and 20 ~ 40 mm away from the root surface in the low and high fertility soils, respectively. Rice planting significantly enhanced nitrification intensity in the rhizosphere of the plant as compared with CK (rice plant free). High fertility improved the growth of rice significantly, especially rice root growth and aerenchyma formation and increased N accumulation in the plant. The difference in soil fertility of paddy field might cause differences in rhizospheric nitrification intensity and rice NO3- absorption, which might lead to stronger rice growth potential and N accumulation ability of the plant in the soil high in fertility. Hence, appropriate increasing soil fertility of red soil paddy fields is of great significance to improving nitrification in rhizosphere of the plants and rice N nutrition in the red soil regions of subtropical China. |
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| Keywords: | paddy soil fertility rice rhizosphere nitrification |
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