土壤中含钾矿物的研究--Ⅰ.含钾矿物中钾的形态及其释放

土壤中的含钾矿物含有大量的钾,这些钾素是植物营养的可能给源,早已引起农业化学家的注意。土壤中的主要含钾矿物有黑云母、白云母、伊利石和长石等。研究土壤中含钾矿物的种类及其性质,对充分利用土壤中的钾素及合理施用钾肥具有一定的指导意义。本文着重研究四种含钾矿物的一些物理化学特性。     

有机钾肥和钾硅钙矿物肥对烤烟生长及烟叶产量质量的影响

为了探讨有机钾肥和矿物钾肥在河南省烤烟上的施用效果,采用大田试验,研究了施用有机钾肥、钾硅钙矿物肥替代15%硫酸钾对烤烟生长及烟叶产量、质量的影响。结果表明,施用有机钾肥、钾硅钙矿物肥替代15%硫酸钾处理比全部施用硫酸钾处理显著提高了圆顶期叶片SPAD值,起到了延缓叶片衰老,保证叶片有足够成熟时间的作用;与全部施用硫酸钾处理相比,用有机钾肥、粒状钾硅钙矿物肥、粉状钾硅钙矿物肥替代15%硫酸钾的3个处理,烟叶产量分别提高16.4%、21.1%和13.0%,产值分别增加5 037.3、10 975.0和3 306.6元/hm2。施用有机钾肥、粉状和粒状钾硅钙矿物肥的3个处理间相比,烟叶产量差异不显著,烟叶产值以施用粒状钾硅钙矿物肥替代15%硫酸钾处理最高,上、中、下部烟叶钾含量显著提高,下部叶和中部叶钾氯比达3.5以上。     

长期施肥下红壤旱地解钾菌变化及其驱动因子

在南方红壤区,研究长期施肥下土壤解钾菌的变化规律及其驱动因素,可为该地区土壤钾素资源管理和钾肥合理施用提供理论依据。基于红壤旱地长期定位施肥试验(始于1986年),选取不施肥(CK)、施氮磷肥(NP)、氮磷钾肥(NPK)和氮磷钾肥配施有机肥(NPKM)处理,分析玉米开花期根际土壤的解钾菌类型和解钾能力及其有机酸和激素含量,并结合玉米根系特性和根际土壤理化性质探讨影响红壤旱地解钾菌变化的关键因子。结果表明:与NPK处理相比,NPKM处理的根长、根表面积、根直径和根体积分别增加了112.3%、174.4%、32.43%和291.5%,根际土壤pH提高了0.67个单位,有机质、非交换性钾和交换性钾分别增加了29.50%、19.34%和53.89%。各施肥处理根际土壤中均存在解钾菌,CK和NP处理的解钾菌均为类芽孢杆菌属,NPK和NPKM处理则均为纤维菌属。与CK处理相比,NP、NPK和NPKM处理下根际土壤解钾菌的解钾效率分别增加了162.4%、139.0%和105.6%,其中NP处理解钾菌的解钾效率最高。偏最小二乘路径模型的结果显示,根系和施肥可同时调控解钾菌的解钾效率。冗余分析(RDA)进一步表明,根系长度和表面积与土壤解钾菌特性呈显著正相关关系(P0.05)。因此,红壤旱地长期不同施肥措施不仅直接影响玉米根系发育特征和根际土壤理化性质,还能显著改变土壤解钾菌群落及其解钾能力,其中根系长度和表面积是调控玉米根际土壤中解钾菌的关键因子。     

硅酸盐细菌NBT菌株解钾效能及对钾的吸持作用

在摇瓶和土壤耗竭条件下研究了硅酸盐细菌NBT菌株的解钾作用以及对作物生长的促进作用。结果表明 ,在摇瓶条件下 ,培养 120h ,NBT菌株可以从钾长石中释放K 159.1mg/L ,比接灭活菌对照 (48.8mg/L)增加 226.02% ;耗竭条件下NBT菌株在未灭菌土壤中的解钾作用与在灭菌土壤中的解钾作用相当。在未灭菌土壤中 ,NBT菌株释放的矿物钾占植株吸钾量的 14.4 %～ 4 3.1% ;不接菌或接灭活菌处理土壤中矿物钾的释放量为零或极少。NBT菌株的解钾效能与土壤中速效性钾及有机质含量密切相关。土柱试验表明 ,供试土壤接种硅酸盐细菌后的土壤滤液中流失的钾比接种灭活硅酸盐细菌后的土壤滤液中流失钾减少 29.6 %～56.5% ;硅酸盐细菌NBT菌株荚膜多糖吸附钾的量占加入钾的量的 31.8%～ 69.4 %。NBT菌株的吸钾作用与NBT菌株本身及荚膜多糖的多少密切相关。     

烟草根际土壤中解钾细菌的分离与多样性分析

土壤中含有丰富的钾元素,但主要以缓效态形式存在于钾长石或云母等硅酸盐矿物中,不能被作物直接吸收利用。解钾微生物能溶解硅酸盐矿物中的钾,提高土壤中作物可利用钾的含量,有望缓解我国钾肥短缺的现状。本研究利用选择性培养基,从烟草根际筛选钾细菌,基于16S rDNA序列分析烟草根际土壤解钾细菌的多样性,通过测定解钾细菌的解钾效能及对烟草的促生作用,筛选有应用潜力的优良解钾细菌菌株。结果表明,从四川、湖北和山东烟区烟草根际土壤分离获得的27株解钾细菌,在解钾固体培养上溶钾圈直径为0.11~0.30 cm。16S rDNA序列分析表明,烟草根际土壤解钾细菌主要包括变形菌门γ亚群(Gammaproteobacteria,85.18%)、变形菌门α亚群(Alphaproteobacteria,3.70%)、变形菌门β亚群(Betaproteobacteria,3.70%)、放线菌门(Actinobacteria,3.70%)和拟杆菌门(Bacteroidetes,3.70%),其中克雷伯菌属(Klebsiella)为优势菌属(66.67%)。27个菌株均有一定的解钾能力,解钾活性为0.59~4.40 mg.L–1。参试菌株均对烟草有一定的促生作用,利用解钾细菌菌液处理烟株20 d后,与对照相比,株高增加0.97%~38.64%,最大叶长增加4.40%~31.02%。本研究筛选出的菌株XF11、GM2、JM19和GL7具有较高的解钾活性和促进植物生长的能力,展现了良好的应用潜力。     

腐殖酸对耕地棕壤固钾与释钾作用的影响研究

通过室内等温培养试验,研究了施用富里酸和胡敏酸对耕地棕壤钾素释放和固定作用的影响。结果表明,施用腐殖酸可以促进土壤钾素的释放,并有随腐殖酸用量提高而增高的趋势。其中,施用富里酸4%,在25℃条件下培养21d,土壤的钾素释放量增加了6.25%,而在相同条件下,施用胡敏酸土壤钾素的释放量仅增加了2.26%;施用腐殖酸可以降低土壤对外源钾的固定量,在施用外源钾400mgkg-1土条件下,与对照比较各处理的固钾量差异均达到了极显著水平。外源钾施用方式对腐殖酸降低土壤固钾作用的影响不同,腐殖酸与土壤恒温培养7d以后施用钾素的固钾量低于钾素与腐殖酸同时施用处理的。腐殖酸对土壤钾素释放和固定的影响是通过对含钾矿物的溶解和层间堵塞以及对钾素的吸附作用实现的。     

解钾细菌C6X对不同富钾矿物含量土壤钾素迁移的影响

为了改善黄土高原地区煤炭开采引起土壤质量急剧退化的现状,该文以玉米为供试植物,通过日光温室短期盆栽的方式,系统研究解钾细菌C6X和玉米生长对土壤钾素迁移的影响.结果表明:1)玉米生长条件下,解钾细菌在富钾矿物质量分数45％上层土壤(0～20 cm)中对速效钾增量的促进作用最佳.2)解钾细菌和玉米生长协同提高上层土壤钾素固定能力,缓效钾增量在土壤富钾矿物质量分数68％为最大值.3)解钾细菌和玉米生长协同促进土壤钾素上移能力,在富钾矿物质量分数45％水平,土壤上移速效钾呈最大值;同时,解钾细菌促进土壤上移速效钾和玉米钾素积累量二者趋于线性稳定,利于土壤钾肥长期管理.因此,解钾细菌和玉米生长协同促进土壤钾素的释放和固定,并促进土壤钾素上移.     

华北平原农田生态系统钾平衡研究

华北平原大部分农田土壤发育在黄河冲积物母质上,矿物钾含量较高,在当前中低产农田中,尤其在有一定秸秆还田的条件下,施用化肥钾增产效果不显著,过多施钾会出现“奢侈性消耗”。在高产条件下,适当施钾对增产仍有一定作用。农田生态系统钾平衡研究对作物生产有重要意义。本文通过3年试验探讨了华北平原农田钾平衡和供钾能力。     

长期施用钾肥对草甸土钾素形态的影响

通过连续13年的钾肥定位试验，研究了施钾对草甸土耕层土壤钾素各形态含量和比例的影响。结果表明，长期施用钾肥较不施钾处理可以增加耕层土中水溶性钾、非特殊吸附钾、特殊吸附钾、非交换性钾的含量和在全钾中的比例，施钾量增加促进了这种状况，同时降低了矿物钾在全钾中的比例。随土层加深，大部分处理的水溶性钾、非特殊吸附钾、特殊吸附钾和非交换性钾含量和比例随之降低，而矿物钾和全钾含量相应处理却随之升高，其中施钾处理的效果明显。     

生物质炭负载解钾菌对土壤酶活性与微生物群落结构的影响

为探究生物质炭负载解钾菌对土壤微生物特性的影响,基于5个处理即空白（CK）、施用化学钾肥（KCl）、接种解钾菌（KSB）、施用生物质炭（BC）、施用生物质炭负载解钾菌（BC-KSB）的黑麦草盆栽耗竭试验,分析不同处理下土壤酶和微生物群落结构的响应特征。结果表明,BC-KSB相比其余施肥处理更有利于提高土壤脲酶、蔗糖酶、酸性磷酸酶和过氧化氢酶的活性,同时也提高了土壤细菌的物种多样性与菌群丰富度,并提高了土壤有益菌群（绿弯菌门、放线菌门、芽孢杆菌属和慢生根瘤菌属）的丰度,抑制了土壤致病菌群（变形菌门和罗河杆菌属）的繁殖。各施肥处理相比CK均显著提升了黑麦草干物质量,且以BC-KSB处理对黑麦草干物质量的提升最为显著。与CK和KCl相比,BC-KSB能显著提高土壤微生物生物量碳、微生物生物量氮、有机质、全氮和速效钾的含量（P <0.05）。冗余分析表明,土壤有机质、速效钾、酸性磷酸酶、脲酶和微生物生物量氮是影响细菌群落结构的主要因子,黑麦草的生长主要受伯克氏菌属和罗河杆菌属的影响较大。可见,BC-KSB对黑麦草产量、土壤养分、土壤酶活性和细菌群落结构均产生了积极的影响,对于改良土壤生态...     

Isolation and identification of potassium-solubilizing bacteria from tobacco rhizospheric soil and their effect on tobacco plants

Soil potassium supplementation relies heavily on the use of chemical fertilizer, which has a considerable negative impact on the environment. Potassium-solubilizing bacteria (KSB) could serve as inoculants. They convert insoluble potassium in the soil into a form that plants can access. This is a promising strategy for the improvement of plant absorption of potassium and so reducing the use of chemical fertilizer. The objectives of this study were to isolate and characterize tobacco KSB and to evaluate the effects of inoculation with selected KSB strains on tobacco seedlings. Twenty-seven KSB strains were isolated and identified through the comparison of the 16S ribosomal DNA. Among them, 17 strains belonged to Klebsiella variicola, 2 strains belonged to Enterobacter cloacae, 2 strains belonged to Enterobacter asburiae, and the remaining 6 strains belonged to Enterobacter aerogenes, Pantoea agglomerans, Agrobacterium tumefaciens, Microbacterium foliorum, Myroides odoratimimus, and Burkholderia cepacia, respectively. All isolated KSB strains were capable of solubilizing K-feldspar powder in solid and liquid media. K. variicola occurred at the highest frequency with 18 strains. Four isolates, GL7, JM3, XF4, and XF11, were selected for a greenhouse pot experiment because of their pronounced K-solubilizing capabilities. After being treated with the four KSB strains, plant dry weight and uptake of both K and nitrogen (N) by tobacco seedlings increased significantly. These increases were higher with the combination of KSB inoculation and K-feldspar powder addition. Isolate XF11 showed the most pronounced beneficial effect on plant growth and nutrient uptake by tobacco seedlings. Combining the inoculation of KSB and the addition of K-feldspar powder could be a promising alternative to commercial K fertilizer and may help maintain the availability of soil nutrients. Further studies are necessary to determine the effects of these bacterial strains on mobilization of potassium-bearing minerals under field conditions.     

解钾细菌与黏土矿物协同促进玉米生长提高土壤养分有效性

为了揭示解钾细菌在西北矿区浅埋古河道土壤中对植物生长和土壤养分利用的影响,通过日光温室短期盆栽的方式,以不同黏土矿物配比的人工培土为基质模拟古河道不同质地土壤,以西北地区常见农作物玉米为宿主,研究解钾细菌在人工培土基质中的微生物数量变化规律,以及二者协同作用对玉米生长和矿质养分吸收的影响。结果表明:1)土壤黏土矿物含量增大有利于提高土壤解钾细菌数量,促进微生物活性。当黏土矿物质量分数为68%,速效钾质量分数约170 mg/kg时,解钾细菌数量最大;2)玉米地上部分干质量、根冠比、根系活力随黏土矿物含量增大而增大,以解钾细菌作用下黏土矿物质量分数68%的玉米生长效果最佳;3)在解钾细菌作用下,植物氮磷钾积累量和土壤养分利用的最佳土壤黏土矿物质量分数为45%、68%和75%,土壤钾素、氮素和磷素最大利用率分别达到65%、53%和17%;4)解钾细菌在土壤钾素含量低时促进土壤磷素吸收,土壤钾素过量时,促进土壤氮磷钾的吸收,提高土壤养分利用率。因此,土壤黏土矿物与解钾细菌相互作用,而且积极影响植物生长和土壤养分的吸收利用,这对进一步探寻适合矿区浅埋古河道土壤的微生物复垦技术,深入改良和开发矿区退化土壤具有重要意义。     

矿物养分来源与缺乏影响人体健康与营养的研究进展

Mineral nutrients are fundamentally metals and other inorganic compounds.The life cycle of these mineral nutrients begins in soil,their primary source.Soil provides minerals to plants and through the plants the minerals go to animals and humans;animal products are also the source of mineral nutrients for humans.Plant foods contain almost all of the mineral nutrients established as essential for human nutrition.They provide much of our skeletal structure,e.g.,bones and teeth.They are critical to countless body processes by serving as essential co-factors for a number of enzymes.Humans can not utilize most foods without critical minerals and enzymes responsible for digestion and absorption.Though mineral nutrients are essential nutrients,the body requires them in small,precise amounts.We require them in the form found in crops and they can be classified into three different categories:major,secondary,and micro or trace minerals.This classification is based upon their requirement rather than on their relative importance.Major minerals such as potassium(K)and phosphorus(P)are required in amounts of up to 10 g d~(-1).The daily requirement of secondary and micro minerals ranges from 400 to 1500 mg d~(-1)and 45μg d~(-1)to 11 mg d~(-1),respectively.To protect humans from mineral nutrient deficiencies,the key is to consume a variety of foods in modest quantities,such as different whole grains,low fat dairy,and different meats,vegetables and fruits.For insurance purposes,a supplement containing various mineral nutrients can be taken daily.     

我国有机肥料研究及展望

本文简要回顾８０年代以来，我国对有机肥料资源、结构组成、营养功效、改土作用机制及改善农作物产品品质作用等方面的一些研究；讨论了有机无机肥配合施用这一施肥制与持续农业发展和建立良好环境生态农业的关系。展望今后有机肥料的研究和发展方向，应尽可能利用有机肥料资源，投入农田参与养分再循环的研究，结合食物链和壤养分库，提高肥料利用率，减少农业非点源污染。重点研究有机肥料循环过程中，碳、氮、磷和微量元素的循环     

Biogeochemical interfaces in soil: The interdisciplinary challenge for soil science

Soil, the “Earth's thin skin” serves as the delicate interface between the biosphere, hydrosphere, atmosphere, and lithosphere. It is a dynamic and hierarchically organized system of various organic and inorganic constituents and organisms, the spatial structure of which defines a large, complex, and heterogeneous interface. Biogeochemical processes at soil interfaces are fundamental for the overall soil development, and they are the primary driving force for key ecosystem functions such as plant productivity and water quality. Ultimately, these processes control the fate and transport of contaminants and nutrients into the vadose zone and as such their biogeochemical cycling. The definite objective in biogeochemical‐interface research is to gain a mechanistic understanding of the architecture of these biogeochemical interfaces in soils and of the complex interplay and interdependencies of the physical, chemical, and biological processes acting at and within these dynamic interfaces in soil. The major challenges are (1) to identify the factors controlling the architecture of biogeochemical interfaces, (2) to link the processes operative at the individual molecular and/or organism scale to the phenomena active at the aggregate scale in a mechanistic way, and (3) to explain the behavior of organic chemicals in soil within a general mechanistic framework. To put this in action, integration of soil physical, chemical, and biological disciplines is mandatory. Indispensably, it requires the adaption and development of characterization and probing techniques adapted from the neighboring fields of molecular biology, analytical and computational chemistry as well as materials and nano‐sciences. To shape this field of fundamental soil research, the German Research Foundation (DFG) has granted the Priority Program “Biogeochemical Interfaces in Soil”, in which 22 individual research projects are involved.     

Understanding mechanisms of soil biota involvement in soil aggregation: A way forward with saprobic fungi?

Soil aggregation is a key ecosystem process that strongly affects soil structure. Soil structure is the three dimensional arrangement of primary particles, organic matter, soil aggregates and associated pores. As such, soil aggregation influences the organization of soil biodiversity and soil-borne biogeochemical processes. Saprobic fungi (SF) have promising but largely untapped potential to offer new perspectives and insights into mechanisms of soil aggregation. The study of SF permits identification of traits that may predict soil aggregation component processes: formation, stabilization and disintegration. The measurement of fungal key traits in experiments aimed at soil aggregation effects will generate data necessary for mechanistic understanding. When such efforts are combined with collecting such information across a range of systems in curated databases this can, by channeling efforts, lead to a step change in our understanding and modeling of organism-mediated soil aggregation mechanisms and changes in functional diversity due to global change.     

The role of ectomycorrhizal communities in forest ecosystem processes: New perspectives and emerging concepts

The fungal symbionts forming ectomycorrhizas, as well as their associated bacteria, benefit forest trees in a number of ways although the most important is enhancing soil nutrient mobilization and uptake. This is reciprocated by the allocation of carbohydrates by the tree to the fungus through the root interface, making the relationship a mutualistic association. Many field observations suggest that ectomycorrhizal fungi contribute to a number of key ecosystem functions such as carbon cycling, nutrient mobilization from soil organic matter, nutrient mobilization from soil minerals, and linking trees through common mycorrhizal networks. Until now, it has been very difficult to study trees and their fungal associates in forest ecosystems and most of the work on ECM functioning has been done in laboratory or nursery conditions. In this review with discuss the possibility of working at another scale, in forest settings. Numerous new techniques are emerging that makes possible the in situ study of the functional diversity of ectomycorrhizal communities. This approach should help to integrate developing research on the functional ecology of ectomycorrhizas and their associated bacteria with the potential implications of such research for managing the effects of climate change on forests.     

胶结物质驱动的土壤团聚体形成过程与稳定机制

团聚体是土壤的基本组成单元，影响着土壤水、气、热及养分的保持和运移。胶结物质在团聚体形成过程中起关键作用，但不同类型胶结物质在土壤团聚体中所起作用与机理尚缺乏系统总结。本论文回顾了土壤团聚体相关的关键理论，梳理了不同地理环境与人为活动下土壤团聚体中胶结物质类型、形态、转化与作用机制，探讨了胶结物质对土壤团聚体结构与稳定性的影响，提出了胶结物质驱动的土壤团聚体自组织形成过程模型，阐明了土壤团聚体的形成与转化机制。最后对土壤团聚体研究领域未来的发展进行展望，特别是在土壤团聚体的原位分析方法、土壤团聚体形成过程的定量化描述、土壤团聚体稳定性在景观尺度上的空间结构、良好土壤结构体培育的产品与技术研发等方面还有待加强。这些工作的开展将对培育良好土壤团聚体、揭示土壤物质循环与演化过程、提高土壤质量和生产力等具有重要的科学意义和生产实践价值。     

西南山地林下经济模式对土壤养分和土壤微生物数量的影响

为进一步加强农林牧业资源共享,推动生态农业的发展,在重庆市荣昌县6种不同的林下经济模式下,分别对土壤养分和微生物数量的变化及其相互关系进行了研究。结果表明,不同的林下经济模式对土壤养分的影响各有差异,有机质和全钾在麻竹林下养禽模式中增加最多,全磷在桉树林下养禽模式中增加最多,全氮、碱解氮、速效钾含量则在马尾松林下养畜模式中增加最多。从微生物总量来看,土壤中表现为桉树林下禽模式最多,其次为桉树林下种菌模式,最少的是麻竹林下种菌模式;腐殖层中最多的是麻竹林下养禽模式,最少的是桉树林下种菌模式。微生物数量与有机质、有效磷和碱解氮呈正相关关系。由于土壤养分和微生物数量的变化趋势不一致,因此在研究林下经济过程中应将二者结合起来。