旱地与稻田土壤微生物生物量周转及其氮素转化对外源添加碳、氮的响应

发布时间：2018-05-14 04:24

本文选题：旱地土 + 稻田土　；参考：《湖南农业大学》2015年硕士论文

【摘要】：土壤微生物对土壤氮素的调控行为已成为农业生态研究关注的重点之一。本研究以亚热带地区典型旱地与稻田土壤为对象,通过添加生物质炭、秸秆、’5N标记硫酸铵和HC标记葡萄糖等,在温度25℃、空气相对湿度100%条件下进行室内培养,研究了亚热带地区农田土壤微生物生物量、周转特征及氮素转化的差异。主要研究结果如下：添加’5N标记硫酸铵与14C标记葡萄糖,研究农田土壤微生物生物量、周转特征及氮素转化特征结果指出：1)添加葡萄糖,从均值上看使金井镇与桃源县早地土壤微生物生物量碳(microbial biomass carbon, MBC)含量比CK分别增加了126.0%、142.1%,稻田土壤MBC含量分别增加了72.8%、36.6%；添加硫酸铵,在培养过程中使金井镇与桃源县旱地土壤MBN含量比CK增加了10.1%-109.5%、12.8%-170.0%,稻田土壤微生物生物量氮(microbial biomass nitrogen, MBN)含量与CK相比,仅在前10d有显著影响；添加硫酸铵与葡萄糖混合液在培养过程中,使金井镇与桃源县早地土壤MBN含量比CK增加了6.3%-356.7%、48.5%-316.6%,稻田土壤MBN含量与CK相比,同样仅在前10d有显著影响。2)金井镇与桃源县旱地土壤MBC的周转时间分别为357 d和370 d,稻田土壤MBC的周转时间分别为132 d和137 d；金井镇与桃源县早地土壤MBN的周转时间分别为238 d和204 d,稻田土壤MBN的周转时间分别为111 d和115 d。3)旱地土与稻田土添加外源碳和氮,在培养结束时,与CK相比,均增加了土壤的矿化氮量,其中旱地土矿化氮量随着培养时间的延长呈现出先逐渐升高后趋于稳定的态势,而稻田土矿化氮量随着培养时间的延长则呈现出先升高、后降低、再趋于稳定的态势。这些结果表明,添加硫酸铵与葡萄糖增加了土壤的矿化氮量,使早地和稻田土壤总微生物生物量增加,且在旱地土壤中效果较为明显：早地土壤微生物生物量的周转时间比稻田土长,土壤MBN的周转快于土壤MBC。添加生物质炭与秸秆,研究农田土壤MBC、MBN含量及氮素转化差异结果指出：1)添加生物质炭,与CK相比,在培养结束时,使桃源县旱地土壤微生物生物量碳(MBC)含量,增加了34.6%；使桃源县旱地土壤MBN含量增加了163.1%,稻田土壤微生物生物量氮(MBN)增加了23.0%；同时,添加生物质炭使桃源县旱地与稻田土的矿化氮量在培养期内高于CK。2)添加秸秆,与CK相比,桃源县早地土壤MBC和MBN含量分别增加了90.4%和203.8%,水稻MBC和MBN含量分别增加了13.4%和19.9%；同时,添加秸秆使旱地土的矿化氮量在培养期内低于CK,而稻田土矿化氮量与CK差异不大。这些结果表明,生物质炭添加可将旱地土MBC和MBN维持在较高水平,而对稻田土MBC和MBN的促进作用不如旱地土；同时,生物质炭添加能增加早地和稻田土壤的矿化氮量,表现出对土壤供氮能力有促进作用。秸秆添加对早地土和稻田土MBC和MBN均有促进作用,且对MBC的影响程度大于生物质炭的添加；然而,秸秆添加可使稻田土矿化氮量明显少于CK对照组。上述结论可为农田土壤管理方式的改进,环境污染的阻控和有机物资源合理利用等提供科学依据。
[Abstract]:Soil microbial regulation of soil nitrogen has become one of the focus of agro ecological research. In this study, the typical dry land and paddy soil in the subtropical region were taken as the object. By adding biomass carbon, straw, '5N' labeled ammonium sulfate and HC labeled glucose, the laboratory culture was carried out under the condition of temperature 25, and air relative humidity 100%. The microbial biomass, turnover characteristics and the difference of nitrogen transformation of farmland soil in subtropical areas were studied. The main results were as follows: adding '5N labeled ammonium sulfate and 14C labeled glucose, studying the microbial biomass, turnover characteristics and nitrogen transformation characteristics of farmland soil pointed out: 1) adding glucose to Jinji town from the mean value The content of soil microbial biomass carbon (microbial biomass carbon, MBC) in the early soil of Taoyuan county was increased by 126%, 142.1%, and MBC content in paddy soil increased by 72.8%, 36.6% respectively. In the process of adding ammonium sulfate, the MBN content in Dryland Soil of Jin well town and Taoyuan county increased 10.1%-109.5%, 12.8%-170.0%, and paddy soil soil in the course of culture. Compared with CK, microbial biomass nitrogen (microbial biomass nitrogen, MBN) content was only significantly affected by the former 10d. In the process of adding ammonium sulfate and glucose mixture, the MBN content in early ground soil of Jin Jing town and Taoyuan county increased 6.3%-356.7% than CK, 48.5%-316.6%, and the MBN content of the paddy soil was similar to that of CK. The turnover time of dryland soil MBC in Jinji town and Taoyuan county was 357 D and 370 D respectively. The turnover time of MBC in paddy soil was 132 D and 137 D, respectively, and the turnover time of the early soil MBN in Jin and Taoyuan counties was 238 D and 204 D respectively. The MBN turnover time of paddy soil was divided into 111 D and 115 respectively. Exogenous carbon and nitrogen increased the amount of mineralized nitrogen in soil compared with CK at the end of culture. The amount of mineralized nitrogen in dryland soil increased gradually and then tended to stabilize with the increase of culture time, while the amount of mineralized nitrogen in paddy soil increased first, then decreased and then tended to stable. The results showed that adding ammonium sulfate and glucose increased the amount of mineralized nitrogen in soil, increased the total microbial biomass in early and rice fields, and was more effective in Dryland Soil: the turnover time of microbial biomass in early soil was longer than that in paddy soil, and the turnover of soil MBN was faster than that of soil MBC. adding biomass charcoal and straw. The results of soil MBC, MBN content and the difference of nitrogen transformation showed that: 1) adding biomass carbon, compared with CK, increased the microbial biomass carbon (MBC) content of dry soil in Taoyuan County by 34.6% at the end of culture, increased the MBN content of dry soil in Taoyuan County by 163.1%, and the microbial biomass nitrogen (MBN) increased by 23% in paddy soil, and added at the same time. With biomass carbon, the amount of mineralized nitrogen in dry land and paddy soil in Taoyuan county was higher than CK.2) with straw added. Compared with CK, the content of MBC and MBN in early soil in Taoyuan county increased by 90.4% and 203.8% respectively, and the content of MBC and MBN in rice increased by 13.4% and 19.9%, respectively, and the amount of mineralized nitrogen in dry soil was lower than CK in the culture period. The amount of mineralized nitrogen in paddy soil was not different from that of CK. The results showed that the addition of biomass carbon could maintain the MBC and MBN of dryland soil at a higher level, while the promotion of MBC and MBN in paddy soil was not as good as dryland soil; at the same time, the addition of biomass carbon could increase the amount of mineralized nitrogen in the early and rice fields, and showed a promotion to the soil nitrogen supply capacity. Straw addition can promote the MBC and MBN in the early soil and paddy soil, and the effect on MBC is greater than the addition of biomass carbon. However, the addition of straw can significantly reduce the amount of mineralized nitrogen in the paddy soil less than that of the CK control group. The above conclusion can be used as an improvement of the management mode of farmland soil, the resistance control of environmental pollution and the rational utilization of organic matter resources. For scientific basis.

【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S154.3

【参考文献】