昆明市松华坝水源区不同利用类型坡地氮素输移规律研究

采用径流小区法对昆明市松华坝水源区牧羊河中游5种不同利用类型坡地地表径流及流失土壤的N（氮）素输移情况,在2007年雨季进行了观测分析。结果表明:不同利用类型坡地N素流失量和水土流失量具有一致性,径流泥沙中,N素流失量分别是裸地>豆地>马铃薯地>林地>草地;径流中,N素流失量依次为裸地>豆地>马铃薯地>林地>草地;5种不同利用坡地截流能力依次为草地>林地>马铃薯地>豆地>裸地。随着截流能力的提高,其径流流失量和土壤侵蚀呈递减趋势,因而N素流失量也逐渐减少;其次,坡度、施肥及土壤自身N素含量也是影响土壤N素流失的重要因素,因此控制水源区水土流失是控制由于N素流失而引起的面源污染的主要途径。     

土壤磷素流失的途径、环境影响及对策

土壤长期过量的P肥(包括化肥和有机肥)投入导致土壤P素水平的提高,从而加大了土壤P素流失的风险。大部分水体富营养化的限制因素是P,土壤P的流失是重要的非点源污染。本文对国内外有关土壤P管理的研究做一综述,内容包括土壤P对水体富营养化的贡献、土壤P的流失途径及影响因素、系列水体P和土壤P指数、土壤P流失控制对策(土地利用管理、立法、政策的改变)等。     

基于RUSLE模型因子的坡地土壤硝态氮地表径流流失经验公式

为了方便有效地预测坡地土壤养分流失,以硝态氮流失为研究对象,根据大量国内外文献资料中的试验数据,通过修正通用土壤流失方程,研究分析硝态氮地表径流流失的特征和影响因素,初步建立了坡地土壤硝态氮地表径流流失预测经验公式。结果表明:硝态氮流失量与五大影响因子之间均呈幂函数正相关关系。利用相关资料对经验公式预测准确性进行检验得出,硝态氮流失量预测值与实测值之间的相对误差为30.28%,模型确定性系数为0.772,模型计算结果与实测结果较为接近。因此,通过分析影响因子与硝态氮流失量之间的定量关系,所建立的硝态氮地表径流流失预测经验公式,可用于不同条件下的坡地地表径流硝态氮流失量预测,为坡地土壤硝态氮流失量预测分析和控制措施优化提供有效手段。     

坡地土壤养分流失研究概况

坡地土壤养分流失与土壤侵蚀发生过程及面源污染的产生息息相关,本文主要从养分流失途径、影响因素、数学模型及调控措施方面阐述了有关坡地土壤养分流失研究的基本情况,并建设性地提出了今后研究的要点和趋势,以期为坡地养分相关研究提供信息和参考。     

杉木人工林皆伐对林地径流水化学特征的影响

杉木人工林皆伐前后径流水化学特征研究结果表明，杉木人工林皆伐后引起林地土壤养分大量流失，皆伐后2年内土壤N素、P素、盐基离子（K^ ,Na^ ,Ca^2 ,Mg^2 ）的可溶性盐分的流失增量分别为20.54kg/hm^2、0.817kg/hm^2、42.67kg/hm^2和774.44kg/hm^2，表晨杉木人工林具有一定的调节、富集和保持土壤养分的能力。     

黄土区土壤钾素径流流失机理研究进展

根据有关文献资料，从形态，有效性，与侵蚀的关系，影响因素与流失模型等方面，对黄土区土壤钾素径流流失机理的研究作一综述。文章指出进一步深入研究黄土区土壤钾素径流流失机理十分必要。     

红壤丘陵岗地区坡地地表径流氮磷流失特征研究

农业非点源污染是水质恶化的主要贡献者,研究坡地农田生态系统N、P流失特征及其影响因素对提高土壤生产力和水环境质量具有重要意义。本研究基于2011年3月至2013年12月花生地(158场)和橘园地(152场)降雨–产流事件中N、P流失的监测数据,探讨南方红壤坡地农田生态系统N、P流失特征及其与降水特征、径流量的关系。结果表明:花生地N、P流失量明显大于橘园地,N流失浓度则是花生地小于橘园地。N、P流失量的季节变化和年际变化均与地表径流量的变化规律一致,养分流失量与地表径流量呈显著正相关关系(P0.01),流失高峰出现在每年的雨季4—6月。两种土地利用方式,P素流失显著低于N素流失,NO3–-N是可溶性养分流失的主要形态。降雨强度(I60)和径流量是影响养分流失的两个主要因素,均与养分流失量呈显著的幂函数关系(P0.01)。红壤坡地果园比坡耕花生地的水土和养分保持效果好,但在降雨产流高峰期仍需加强肥料施用管理和相关阻控措施的实施。     

闽东南土壤流失人工神经网络预报研究

利用径流实验场观测资料，首次提出应用人工神经网络模型实现土壤流失预测预报，并通过模拟计算进行了检验，与通用土壤流失方程（USLE）比较，人工神经网络模型预报模拟精更高，从而为闽东南土壤流失预测预报提供准确信息。     

坡耕地氮磷流失及其控制技术研究进展

坡耕地N、P流失是造成农业面源污染的重要原因.文章综述了国内外有关坡耕地N、P流失的过程特征,降雨、土壤、地形、耕作与管理因素对N、P流失的影响等方面工作的研究进展,探讨了不同控制措施,如覆盖、植物篱、保护性耕作、坡改梯等,控制N、P流失的控制机制、效果和可操作性;并进一步对坡耕地N、P流失的研究与控制方面等今后应加强研究的趋势进行了展望.     

水文因素影响稻田氮磷流失的研究进展

水文因素为农田氮磷元素的迁移提供了动力和载体,对稻田氮磷元素的流失具有重要影响。利用新型的稻田水分管理模式以代替传统的水分管理模式,对于有效控制面源污染具有重要意义。在综合调研国内外已有研究成果和最新进展的基础上,阐述了稻田氮磷流失特征、传统水分管理模式的弊端,并从新型稻田水分管理模式的种类、削减氮磷流失的效果与机理、与水平衡模型、营养负荷模型等结合应用等几个方面综述了国内外水文因素影响稻田氮磷流失的研究现状。进行稻田土壤吸附氮磷容量及人工调节机制的研究,在部分地区开展流域化水分管理系统研究,以及适用于我国稻田的水平衡模型和营养负荷模型的建立和深入研究应为今后我国关于水文因素影响稻田氮磷流失方面研究的一些方向。     

Highlights and perspectives of soil biology and ecology research in China

As seen for the publications in several distinguished soil related journals, soil biology and ecology is booming in China in recent years. This review highlights the major findings of the soil biology and ecology projects conducted in China during the past two decades. Special attention is paid on the responses of soil biota to environmental change, and the roles of soil functional groups in C transformation, nutrient cycling and pollution remediation. We also point out the future challenges facing the Chinese soil biologists and soil ecologists. In the future, more systematic studies rather than scattered case studies are needed, more controlled field experiments rather than short-term laboratory studies should be encouraged. Besides, we need to focus more on the linkage between aboveground and belowground organisms, the interactions between different groups of soil food web, and the coupling of observation with modeling. It is essential to employ the state-of-the-art technology in research of soil biology and ecology because to answer the emerging scientific questions relies heavily on the development of new technology. Our ultimate goals are to push forward the research on soil biology and ecology in China and to encourage the interaction and collaboration between the international community and research groups in China.     

Effects of irrigation and nitrogen fertilizer on yield,carbon inputs from above ground harvest residues and soil organic carbon contents of a sandy soil in Germany

To better understand the complex interactions between irrigation and nitrogen fertilizer application on soil organic carbon content, the results from long‐term field experiments over a period of 40 years were analysed. The combined effect of irrigation and nitrogen fertilizer rates on crop yields, carbon input by above ground harvest residues and soil organic carbon content has been investigated at a site on a sandy soil in northeast Germany. Combined with nitrogen fertilizer application, irrigation has frequently had a significantly positive effect on crop yield and carbon inputs from above ground harvest residues. However, enhanced carbon inputs to the soil under irrigation did not lead to significantly greater soil organic carbon contents. As the combination of irrigation and nitrogen also improved microbial decomposition by changing of above ground harvest residues C/N ratio and soil moisture, the effect of an additional input of carbon from above ground harvest residues was nullified.     

基于文献计量的土壤有机碳与土壤微生物多样性研究前沿态势分析

为了系统了解国际上土壤有机碳与微生物多样性的研究进展,基于Web of Science数据源,利用Web of Science数据库分析工具和Thomson Data Analysis(TDA)、社会网络分析与可视化工具Netdraw和Ucinet,从论文年度变化趋势、全球研究实力国家、机构分布和力量比较、基金资助机构和主题分布、机构合作和研究内容等方面,对1992~2015年的相关论文,尤其是近10年来土壤有机碳及其影响因素的相关文章进行计量分析。结果表明:(1)论文数量呈逐年增长态势,土壤有机碳与土壤微生物多样性研究主要集中在欧美发达国家(地区);美国和德国综合影响力最高,英国、瑞典、瑞士、荷兰论文篇均被引较高,以中国科学院为代表的中国机构在该领域研究增长较快,研究论文最多,但论文整体质量有待提高。(2)中国国家自然基金资助机构产出论文最多;美国国家科学基金会资助论文篇均被引最高,其次是德国研究基金会,中国科学院科学基金名列第3,各国在共同资助的研究主题基础上,各有其特色主题;美国的一些研究机构是全球该领域研究合作交流的中心,其次是德国和中国中科院。(3)土壤有机质、土壤有机碳、凋落物分解、氮、磷、微生物生物量、土壤性质、气候变化、碳固定是该领域10年来的热点研究主题。未来应加强国际合作研究,关注土壤重金属、凋落物分解和微生物呼吸等相关主题,以提高我国研究水平,将相关研究成果及时应用于解决相应的实际问题。     

The effect of plant hedgerows on the spatial distribution of soil erosion and soil fertility on sloping farmland in the purple-soil area of China

Recently the effect of plant hedgerows on controlling soil and water loss has been well recognized, and this technology has been widely applied in the world. However, there are few studies on hedgerows’ effect on soil fertility of sloping lands. With an 8-year fixed field experiment, we investigated the effect of two different hedgerows on soil fertility through comparing with the control. Our results showed that along contour lines across the field, clay particles tended to accumulate above plant hedgerows but to be eroded downward below hedgerows. Except for potassium (K), all plant nutrients and soil organic matter showed the same distribution pattern as clay particles. K, however, was evenly distributed in the field without any noticeable influence from hedgerows. Since the beginning of our field experiment, soil phosphorus (P) kept accumulating, while soil organic matter and K were in depletion. Taken together, our results suggest that better nutrient management for the sloping lands should reduce P but increase farm manure and K. As far as the whole sloping field is concerned, special attention in nutrient management should be paid to the soil stripes below hedgerows, the portions suffering from more serious soil erosion.     

环境土壤学——回顾与展望

环境土壤学是一门新兴的、土壤学和环境科学交叉融合的综合性学科，其研究重点从早期服务于农业安全生产发展至现在的土壤环境与健康，本文从土壤外源物质侵袭和土壤质量演变对土壤环境影响等方面回顾了环境土壤学发展历程。土壤污染物对土壤环境质量影响是以土壤元素背景值和环境现状调查为基础，以明确污染物形态，揭示土壤反应过程机制，评估污染效应，开展土壤环境修复工程为主线不断发展更新。土壤质量演变研究中碳、氮、硫、磷元素循环从土壤肥力和农业非点源污染的探讨拓展至土壤对全球气候变化的适应与响应；土壤退化研究则从对土壤生产力或功能丧失的研究发展至全球气候变化背景下农业发展可持续性及土壤生态功能的研究。环境土壤学在今后有四个重要发展趋势：提倡多学科交叉融合；评估全球气候变化对土壤元素循环的潜在影响；完善土壤健康评价框架中的土壤环境评价指标建立；学科发展服务于国家重大需求。     

Size matters: What have we learnt from microcosm studies of decomposer fungus–invertebrate interactions?

The ongoing research ‘boom’ in soil ecology has been advanced by a widespread use of laboratory experiments to investigate mechanisms that could not be unravelled with field observations alone. Interactions between soil fungi and invertebrates have received considerable attention due to their trophic and functional importance in belowground systems. Saprotrophic cord-forming basidiomycete fungi are major agents of primary decomposition in woodland ecosystems, where they are also an important source of nutrition for fungal-feeding soil invertebrates. A plethora of microcosm experiments, with their main benefit being that they enable most variables to be kept constant while just a few are manipulated, have provided detailed insights into the ecology of fungus–invertebrate interactions. This review identifies important trends from this body of work (including a meta-analysis of grazing effects on fungal growth and wood decomposition) and explores the extent to which these patterns are supported by the few related experiments conducted in more complex mesocosm and field systems. Grazing in microcosms reduced fungal growth and increased decomposition, but with interaction-specific magnitude, reflecting invertebrate feeding preferences for different fungi. Macro-invertebrates (woodlice and millipedes) had stronger effects than micro- (e.g. nematodes) and meso- (e.g. collembola) invertebrates. This greater grazing pressure generally increased enzyme activities beneath mycelia during interactions in which wood decay was increased. Top-down effects of fungal-feeding can be extrapolated to more complex systems, but only for macro-invertebrates, particularly woodlice. Soil enzyme activity was stimulated, in microcosms and more complex systems, by short-term or low intensity grazing, but reduced when large areas of mycelium were removed by high-intensity grazing. Effects of differential fungal palatability on invertebrate populations are evident in microcosm studies of collembola. These bottom-up effects can be extrapolated more broadly than top-down effects; fungal community dominance determined collembola abundance and diversity, in mesocosms, and woodlouse abundance in the field. Using, as a case study, a series of experiments conducted at a range of scales, mechanisms underlying potential climate change effects on grazing interactions and decomposition are also explored. Biotic effects on decomposer community functioning are heterogeneous, depending on fungal dominance and the density of key macro-invertebrate taxa.     

保存过程对土壤生化指标的影响及保存土样的应用

土壤样品的生化指标反映了样品采集时期的生态与环境信息,具有极为重要的科学研究价值。样品的生化指标在保存过程中是否发生变化,是保存样品应用中应关注的重点问题。本文总结了各类土壤生化指标在不同保存条件、保存时间下的变化,表明长期保存的土壤样品适用于全量元素含量测定、土壤微生物群落结构分析、DNA/RNA序列分析、土壤污染物分析和土壤酶活性的比较研究,而土壤速效成分以及呼吸、硝化等代谢过程相关指标则不宜采用保存土样。土样长期保存应采用风干、磨口玻璃瓶密封、常温保存的方式。保存土样应用过程中应注意避免取样、分析时的环境污染,采用合适的分析测试技术,并考虑不同类型土壤保存效应的差异。随着分析技术的发展,保存土样中更多的历史环境信息将得以发掘,发挥出更大的科研价值。     

农业生产对石灰性土壤无机碳库损失的影响

一般认为,土壤无机碳（SIC）周转缓慢,在全球农田碳循环及应对气候变化等方面的作用有限。近年来越来越多的证据表明,土壤无机碳转化速率也较快,在土壤肥力、碳库转化和调节大气二氧化碳浓度方面的作用不容小觑。总结了国内外关于农田无机碳方面的研究进展,强调无机碳在农田土壤固碳、缓冲土壤pH等方面具有重要作用;农业生产特别是氮肥大量施用导致我国一些地区农田无机碳消耗,加速土壤酸化,增加了作物重金属污染风险,影响了农田土壤健康。认为我国“秦岭-淮河”南北分界区非石灰性土壤与石灰性过渡区、山东半岛棕壤与潮土过渡区、东北黑土与黑钙土过渡区等区域SIC含量相对较低、降水量相对较高,长期大量施用氮肥会导致农田表层SIC发生损失,属SIC损失敏感区。提出应进一步研究的问题,包括：查明农业生产特别是施用氮肥对土壤无机碳去向的影响,研究土壤有机碳-二氧化碳-钙离子-无机碳相互作用机理及对氮肥的响应,在全球碳循环及土壤碳收支平衡研究中,应考虑人类活动特别是农业生产对土壤无机碳库的影响。建议定期监测我国无机碳损失敏感区农田土壤无机碳含量,合理施肥以减少土壤无机碳损失。     

呼伦湖流域不同利用方式草场水土和氮磷流失

摘 要：为了研究不同利用方式草场水土和氮磷流失规律及原因,在呼伦湖流域选择传统放牧草场、草库伦草场、不放牧草场三种利用方式草场,用模拟降雨的方法进行了水土及氮磷随径流流失试验。结果表明：两种雨强下,传统放牧草场水土流失最严重。相同雨强下,总氮流失量：草库伦草场>传统放牧草场>不放牧草场;总磷流失量：传统放牧草场>草库伦草场>不放牧草场。同一种利用方式草场径流中总氮、总磷浓度与降雨强度关系不显著。草库伦草场可有效防止水土流失。传统放牧草场和草库伦草场的氮磷排放负荷与累积径流量之间存在线性关系,而不放牧草场的存在指数关系。该研究可为探讨呼伦湖流域草场合理利用、水环境的保护和面源污染的治理提供参考。     

土壤无机氮解吸模型及其特征值生物效应研究

8种土壤126个氮素解吸实验表明,解吸模型C=ClH-a能模拟土壤铵态氮、硝态氮的解吸动态规律,其中有125个实验的复相关系数达到极显著水平。盆栽试验和田间试验结果表明,对生长期较短的空心菜、菜心和莴苣而言,土壤氮素可解吸量Q和土壤溶液氮素初始浓度C li与供试蔬菜的氮素吸收量和产量之间有显著的抛物线型关系,为评价土壤氮素生物有效性和临界指标提供了一种新方法。