【作者】 王万江；

【导师】 方升佐；

【作者基本信息】 南京林业大学 ， 森林培育， 2010， 硕士

【摘要】 土壤有机碳(SOC)的含量及其动态平衡是反映土壤质量或土壤健康的一个重要指标,直接影响土壤肥力和作物产量的高低。本文比较研究了苏北地区杨-农复合经营系统不同经营模式的土壤总有机碳库特征,土壤微生物量碳库特征,土壤可溶性有机碳库特征,土壤可矿化有机碳库特征,期望得到农林复合生态系统土壤的碳储量、碳释放量、空间变异和年动态变化,为碳汇分析提供有效数据。主要研究结果如下:1.三种经营模式(K、P、W)土壤有机碳含量都有随土壤剖面深度增加而降低的趋势,且表层土(0-20cm)的有机碳含量都相对较高,表层土以下有机碳含量迅速降低。方差分析表明,三种模式不同层次土壤有机碳含量差异极显著(P<0.01)。2.三种模式土壤微生物生物量碳在垂直分布上总体都有随土壤深度的增加而降低的趋势,分布规律相似。方差分析表明,K模式和W模式土壤微生物生物量碳含量都是0～20cm与其余层次差异极显著(P<0.01),而其余层次间差异不显著(P>0.05)。三种模式土壤微生物生物量碳存在明显的季节变化,变化趋势基本一致,即出现冬春两季值偏低,夏秋两季值偏高的山峰形状曲线。方差分析表明,季节对三个模式土壤微生物生物量碳都有极显著影响(P<0.01)。不同模式土壤微生物生物量碳含量与有机碳含量之间存在显著相关(P<0.01)。3.三种模式土壤可溶性有机碳含量在垂直分布上总体都有随土壤深度的增加而降低的趋势,分布规律相似。土壤水溶性有机碳为三种模式不同土壤层次间差异显著(P<0.05)。三种模式土壤可溶性碳含量存在明显的季节变化,方差分析表明,季节变化对三种模式的土壤剖面DOC均值有极显著影响(P<0.01),说明该模式土壤DOC含量与季节变化(水、肥、气、热)的影响较大。4.三种模式土壤可矿化碳含量在垂直分布上总体都随土壤层次的增加,土壤可矿化碳都存在明显的季节变化,且规律相似,表现为暖季高而冷季低的峰状曲线。方差分析表明,季节对三个模式土壤可矿化碳含量都有极显著影响(P<0.01)。更多还原

【Abstract】 Soil organic carbon (SOC) content and its dynamic balance, an important indicator of a direct impact on the level of soil fertility and crop yield, reflect soil quality or soil health. In this paper, soil organic carbon, microbial biomass carbon, dissolved organic carbon, soil mineralizable organic carbon were investigated in three poplar-crop agroforestry systems in order to provide an effective carbon sink data of soil carbon storage, carbon emission, spatial variability and the annual changes. The major findings are as follows:1. Soil organic carbon content decreased with increasing of soil depth in all three management patterns (K, P, W). The organic carbon concentrations in surface soil (0-20cm) had relatively high, then organic carbon content decreased rapidly as the soil depth increasing. Variance analysis showed that soil organic carbon content was significantly different among the three patterns (P <0.01).2. Microbial biomass C also decreased with soil depth increaseing, similar distribution to soil organic carbon. Analysis of variance showed that microbial biomass C content in K pattern and W pattern was significantly different between the depth of 0 ~ 20cm and the other layers(P <0.01), while no significant difference was observed between the other layers (P> 0.05).3. A significant seasonal variation in microbial biomass C was found in the three patterns, and value appeared low in winter and spring, whereas values in summer and autumn reached high. Analysis of variance showed that growth season had significant effects on microbial biomass C in the three patterns (P <0.01). Microbial biomass carbon was significantly related to organic carbon content (P <0.01).4. Similar pattern in the vertical distribution of soil dissolved organic carbon was also observed. Soil dissolved organic carbon in different soil layers was significantly different for the three management patterns (P <0.05).Analysis of variance showed that seasonal changes in DOC for soil profiles of three patterns were very significant (P <0.01), suggesting that the variation of soil DOC content was greatly influenced by management pattern and seasonal management practices (water, fertilizer, gas, heat).5. Mineralizable soil carbon content in the vertical distribution was different from the trend mentioned above, increasing as the soil layers deepening. Soil carbon mineralization showed an obvious seasonal variation, and trend was high in warm season and low in cold season. Analysis of variance showed that growing season had a significant effect on mineralizable carbon content of soil (P <0.01).更多还原