长期施肥对红壤水稻土碳氮分布影响的研究

发布时间：2018-05-30 07:39

本文选题：水稻土 + 土壤渗漏液　；参考：《东北师范大学》2015年硕士论文

【摘要】：红壤是我国南方亚热带地区重要的土壤类型,水稻土是重要的人工湿地生态系统。近几十年来,随着自然环境的恶化,加之人类活动的干扰,导致红壤水稻土结构破坏严重,肥力明显降低,严重影响了红壤水稻土地区的水稻产量和品质。土壤团聚体是土壤结构的重要组成部分,在提高土壤肥力和改善土壤结构方面具有重要意义。不同施肥方式下土壤团聚体分布及土壤团聚体中碳氮含量存在差异。施肥是改善土壤中碳氮等养分含量的重要措施,但过量施肥会导致土壤中碳、氮淋失量增多,因此,本论文依托中国科学院千烟洲红壤丘陵综合试验站中的长期定位施肥样地,利用负压法进行土壤渗漏液采样,并用湿筛法进行土壤团聚体的筛分,研究不同施肥种类秸秆还田(ST)、有机肥(OM)、化肥(NPK)对红壤水稻土早稻和晚稻不同种植阶段中碳素和氮素淋失状况及全土和团聚体中碳、氮含量分布的影响。主要研究结果如下:(1)红壤水稻土中DOC和NH4+-N的淋失量均是水稻营养生长期高于水稻生殖生长期;红壤水稻土中氮素淋失以铵态氮(NH4+-N)为主,三种不同施肥方式下,施用NPK处理方式下红壤水稻土中NH4+-N淋失量最多,三种不同施肥方式下,施用OM处理方式下使红壤水稻土中可溶解性有机碳(DOC)淋失量最多。(2)红壤水稻土中NH4+-N、DOC、总有机碳(SOC)和总氮(TN)含量在不同施肥处理方式下存在差异,其中施用NPK显著增加了红壤水稻土中TN含量,而施用OM则显著提高了红壤水稻土中SOC含量。(3)红壤水稻土土壤渗漏液中DOC含量和NH4+-N含量分别随红壤水稻土中SOC含量和TN含量的增加而增多,均呈显著正相关关系(P0.01)。(4)不同施肥处理方式下,红壤水稻土中的团聚体分布主要为粉砂和粘粒(63μm)部分,其比例约占全土的一半。(5)不同种类肥料的施用均能增加红壤水稻土及其不同粒级团聚体中的碳氮含量,四种处理方式中,施用OM能够显著增加红壤水稻土全土中的有机碳和全氮的含量,同时也能明显增加不同粒级团聚体中的有机碳和全氮的含量。
[Abstract]:Red soil is an important soil type in the subtropical region of southern China, and paddy soil is an important constructed wetland ecosystem. In recent decades, with the deterioration of natural environment and the interference of human activities, the structure of paddy soil in red soil has been destroyed seriously, and the fertility of paddy soil has been significantly reduced, which has seriously affected the yield and quality of rice in paddy soil area of red soil. Soil aggregate is an important component of soil structure, which plays an important role in improving soil fertility and soil structure. The distribution of soil aggregates and the content of carbon and nitrogen in soil aggregates were different under different fertilization methods. Fertilization is an important measure to improve soil carbon and nitrogen content, but excessive fertilization will lead to the increase of soil carbon and nitrogen leaching. Therefore, this paper relies on the long-term location of fertilization sample in Qianyanzhou red soil comprehensive experimental station of Chinese Academy of Sciences. The negative pressure method was used to sample the soil leakage and the wet sieve method was used to screen the soil aggregate. The effects of different fertilizer types on carbon and nitrogen leaching in early rice and late rice in red soil and the distribution of carbon and nitrogen in whole soil and aggregate were studied. The main results were as follows: (1) the leaching loss of DOC and NH4 N in red paddy soil was higher than that in rice reproductive growth stage, and the nitrogen leaching in red paddy soil was dominated by ammonium nitrogen (NH _ 4-N). The amount of NH4 -N leaching in paddy soil of red soil was the most under the treatment of NPK, and under three different fertilization methods, the leaching loss of NH4 was the most in the paddy soil of red soil. The content of soluble organic carbon (NH4), total organic carbon (TOC) and total nitrogen (TNC) in paddy soil of red soil were different under different fertilization treatments. The application of NPK significantly increased the TN content in paddy soil of red soil. The content of DOC and NH4-N in soil leakage of red paddy soil increased with the increase of SOC content and TN content, respectively. Under different fertilization treatments, the distribution of aggregates in paddy soils was mainly composed of silt and clay (63 渭 m). Its proportion is about half of the whole soil.) the application of different kinds of fertilizers can increase the carbon and nitrogen content in red paddy soil and its different grain-grade aggregates. The application of OM could significantly increase the content of organic carbon and total nitrogen in the whole soil of red paddy soil, but also increase the content of organic carbon and total nitrogen in the aggregates of different grain levels.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S153.6

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