不同肥力红壤水稻土根际团聚体组成和碳氮分布动态

发布时间：2018-03-14 18:39

本文选题：红壤水稻土　切入点：团聚体　出处：《土壤学报》2017年01期 　论文类型：期刊论文

【摘要】：研究水稻种植期间表层土壤团聚体数量及其有机碳、全氮含量的变化,对揭示人为耕作的影响、认知土壤肥力的演变规律具有重要意义。选择两种不同肥力的红壤性水稻土进行田间根袋试验,分别于水稻插秧前、分蘖期、孕穗期和成熟期采样,分析了水稻生长过程中根际和非根际土壤团聚体组成、稳定性以及有机碳、全氮分布的动态变化。结果表明,低肥力土壤团聚体以0.25 mm大团聚体为主(56.2%~64.0%),0.25~1 mm粒级团聚体含量最高;除1~2 mm粒级外,水稻生育期内根际土壤各粒级团聚体含量均有显著变化;取样时期、根际作用与取样时期的交互效应对0.25~1 mm和0.053~0.25 mm粒级含量有显著影响。高肥力土壤中以0.25 mm微团聚体为主(59.8%~72.0%),0.053~0.25 mm粒级团聚体比例最高,取样时期显著影响0.25 mm大团聚体含量,根际作用与取样时期的交互效应对2 mm粒级含量有极显著影响。与非根际相比,根际土壤大团聚体的破坏率较低,平均重量直径(MWD)较高,种植水稻有助于提高根际土壤的稳定性。两种肥力土壤团聚体中有机碳和全氮含量均表现为1~2 mm粒级最高,0.053~0.25 mm粒级最低,大团聚体中显著高于微团聚体。根际土壤中,水稻成熟期各粒级团聚体有机碳含量与插秧前无显著差异,而分蘖期和孕穗期有明显波动;水稻的生长降低了大团聚体中的全氮含量,对高肥力土壤的影响更为显著。总体而言,低肥力土壤中,根际作用主要影响团聚体组成和稳定性,取样时期影响团聚体碳氮含量;高肥力土壤中,团聚体组成和碳氮分布受根际作用和取样时期的共同影响。
[Abstract]:In order to reveal the effect of artificial tillage, the changes of aggregate number, organic carbon and total nitrogen content in surface soil during rice cultivation were studied. It is of great significance to understand the evolution of soil fertility. Two kinds of red soil paddy soils with different fertility were selected to carry out the field root bag experiment, which were sampled before transplanting rice seedlings, tillering stage, booting stage and mature stage, respectively. The composition, stability and distribution of organic carbon and total nitrogen of rhizosphere and non-rhizosphere soil aggregates during rice growth were analyzed. The results showed that the content of 0.251mm aggregates was the highest in low-fertility soil aggregates. With the exception of 1 ~ 2 mm grain size, the content of grain aggregates in rhizosphere soil was significantly changed in rice growing period, and the sampling period, The interaction between rhizosphere and sampling period had a significant effect on the content of 0.25mm and 0.0530.25mm grains. In high-fertility soil, the percentage of 0.25mm microaggregates was the highest, and the percentage of 0.25mm microaggregates was the highest. The sampling period significantly affected the content of 0.25mm large aggregates. The interaction between rhizosphere and sampling period had a significant effect on grain size of 2 mm. Compared with non-rhizosphere, the destruction rate of macroaggregates in rhizosphere soil was lower and the average weight diameter was higher than that in non-rhizosphere soil. The content of organic carbon and total nitrogen in the aggregates of the two fertility soils was the highest, 0.053 ~ 0.25 mm and the lowest, and the content of organic carbon and total nitrogen in the rhizosphere soil was significantly higher than that in the large aggregates, and in the rhizosphere soil, the content of organic carbon and total nitrogen in the rhizosphere soil was higher than that in the rhizosphere soil. There was no significant difference between the content of organic carbon in the aggregates at maturity stage and that before transplanting, but there were obvious fluctuations in tillering stage and booting stage, and the total nitrogen content in the large aggregates was decreased by the growth of rice. In general, rhizosphere effects on composition and stability of aggregates in low fertility soils, carbon and nitrogen contents in aggregates during sampling period, and carbon and nitrogen contents in high fertility soils were significantly affected by Rhizosphere in low fertility soils. The composition of aggregates and the distribution of carbon and nitrogen were influenced by rhizosphere and sampling period.
【作者单位】：土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所);中国科学院大学;
【基金】：国家重点基础研究发展规划(973)项目(2015CB150501) 国家自然科学基金项目(41171233)资助~~
【分类号】：S153.6

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