施用生物炭对农田生态系统影响的研究进展

从施用生物炭对土壤理化性状、土壤生物、土壤碳截留、作物产量、温室气体排放的影响等方面,总结分析了施用生物炭对农田生态系统的影响。结果表明,施用生物炭能够改善土壤理化特性和微生物生境,提高养分利用率,但对作物的增产效应具有一定的不确定性。生物炭的稳定性对增加农田土壤碳截留有重要作用,其降解过程目前尚不清楚。添加生物炭影响土壤有机质分解即激发效应,但激发效应的方向和幅度的变异较大。在影响温室气体排放方面,施用生物炭能有效减少N2O排放,但对CO2和CH4的减排效应具有较大的不确定性,生物炭的性质、施用量、土壤类型和肥力状况等因素是导致这些不确定性的主要原因,今后应综合考虑以上因素开展长期定位试验,客观评价生物炭对农田生态系统功能的影响和作用。     

生物炭改良盐碱地效果及其对植物生长的影响研究进展

土壤盐碱化被视为限制全球土壤生产力、粮食安全和生态系统的重要因素,全球有大面积的盐碱地,因而又是最重要的边际土地资源。近年来,生物炭在改良土壤结构、提高土壤肥力以及固碳减排等诸多领域中表现出极大的应用潜力。研究表明,生物炭的施用能够改善盐碱地土壤理化性质、提高碳含量和促进植物生长,可作为盐碱地改良的有效措施使用。然而,生物炭对盐碱地土壤改良和对植物生长的影响机理较为复杂,有待深入的研究。本文梳理了当前国内外生物炭改良盐碱地土壤结构、化学性质、养分有效性、生物活性的效果及其对植物生长影响的研究进展,在系统分析生物炭改良盐碱地土壤的机制基础上,对生物炭改良盐碱地的应用潜力进行了展望,以期为生物炭在盐碱地改良上的高效利用提供参考。     

生物炭固碳减排作用的研究进展

近年来,生物炭(biochar)在土壤改良,污染物修复和固碳等方面受到了国内外研究人员的普遍关注.特别是利用生物质废弃物制备生物炭,被认为是一种非常有前景的并能够实现碳封存和减缓气候变暖目的的管理策略.为此,本文重点概述了生物炭固碳的原理、特点、原因及潜力,并展望了生物炭固碳减排作用的理论研究方向,为生物炭固碳技术的应用和推广提供一定的借鉴.     

生物炭对紫色土农田土壤NO排放的影响

为探明生物炭对紫色土农田土壤NO排放的影响,利用静态箱-化学发光氮氧化物分析法对夏玉米-冬小麦轮作土壤施用生物炭后的NO排放进行了为期一年(2013年6月至2014年5月)的原位观测,比较了生物炭与化肥混施处理(BCNPK)和常规施肥处理(NPK)的紫色土NO排放特征,无肥(CK)作为计算排放系数的对照。结果表明,玉米生长季,NPK处理下的土壤NO排放速率、累积排放通量及排放系数与BCNPK处理下相应参数之间均呈极显著差异(P0.01)。施用生物炭后,NO排放速率、累积通量及排放系数分别降低了73.1%、77.4%和85.5%,但在小麦季两种处理之间的差异均不显著(P0.05)。此外,在玉米季和小麦季,BCNPK处理单位产量的综合温室效应(yield-scale GWP)分别比NPK处理降低了79.4%和26.4%。因此,在同等氮肥施用量的条件下配施生物炭既能保证紫色土农田土壤作物不减产又能降低NO的排放。     

生物炭与沼液混施对杨树人工林土壤温室气体排放的长期影响

  目的  明确不同生物炭和沼液添加量对杨树人工林土壤温室气体排放的影响。  方法  依托长期生物炭和沼液混施野外观测样地,于2019年7月到2020年1月测定不同生物炭（B0, B1, B2）和沼液（C, L, M, H）添加处理的土壤温室气体排放通量,于2019年9月和2020年1月测定土壤理化性质。通过统计分析,揭示生物炭和沼液对土壤温室气体排放的影响。  结果  添加生物炭的土壤总碳（B1: 2.42 ± 0.14%, B2: 2.75 ± 0.14%）显著高于未添加生物炭的土壤（B0: 1.83 ± 0.04%）。同样,添加生物炭的土壤总氮（B1: 0.22 ± 0.01%, B2: 0.24 ± 0.01%）显著高于未添加生物炭的土壤（B0: 0.18 ± 0.01%）。沼液添加显著提高土壤总氮含量,但生物炭与沼液对土壤总碳和总氮不存在显著交互作用。在冬季,沼液和生物炭均显著影响土壤NH₄+-N含量,且两者存在显著性的交互作用;沼液显著增加土壤NO₃?-N含量。在野外监测时间内,沼液显著提高了土壤N₂O和CH₄的累积排放量,增强了总增温潜势。与未添加沼液（C）处理相比,低（L）、中（M）和高剂量（H）沼液添加处理的总增温潜势分别增加了30%、40%和44%;而生物炭对土壤温室气体累积排放量和总增温潜势的影响不显著。  结论  生物炭单次添加7年后对温室气体排放的抑制效应不明显,甚至可能增加土壤温室气体的排放。沼液每年3次添加显著促进土壤温室气体的排放。因此,建议进一步研究老化效应对生物炭抑制土壤温室气体排放能力的潜在机制以及生物炭与沼液（氮肥）配施的最佳比例,以改善土壤环境并减少温室气体排放。     

生物炭和腐殖酸施用对稻麦轮作系统CH4和N2O综合温室效应的影响

生物炭和腐殖酸对土壤C、N循环和作物产量均具有深刻影响。该试验以稻麦轮作系统为研究对象,探究生物炭和腐殖酸在经过1 a陈化后对土壤肥力、作物产量和温室气体排放的持续影响。设置了6个处理：B0F0(对照,不添加生物炭和腐殖酸);B0F1(不添加生物炭,腐殖酸添加量为0.6 t/hm²);B0F2(不添加生物炭,腐殖酸添加量为1.2 t/hm²);B1F0(生物炭添加量为20 t/hm²,不添加腐殖酸);B1F1(生物炭添加量为20 t/hm²,腐殖酸添加量为0.6 t/hm²);B1F2(生物炭添加量为20 t/hm²,腐殖酸添加量为1.2 t/hm²)。结果表明：1)试验期内,与B0F0相比,生物炭显著增加了稻麦两季土壤有机碳含量;腐殖酸增加了稻季土壤有机碳含量,对麦季土壤有机碳含量无显著影响;单独施用生物炭或腐殖酸对水稻和小麦产量均没有显著影响,生物炭和腐殖酸混施处理显著提高了小麦产量,增幅为1.0%～5.0%,对水稻产量没有显著影...     

生物炭主要类型、理化性质及其研究展望

【目的】 生物炭作为工农业生产副产品低碳利用的有效手段,其改善土壤及提高作物品质的有益功效已被逐步认识,但对其研究报道分散且差异较大。对已有研究进行梳理总结,可为生物炭生产施用以及形成有效的产业链提供科学依据。 主要进展 1）生物炭全碳含量在 30%～90% 之间,平均 64%。生物炭碳含量由大到小来源依次是木质、秸秆、壳类、粪污和污泥。秸秆类生物炭碳含量大多为 40%～80%,木质类生物炭在 60%～85%。生物炭灰分含量在 0～40% 之间变动,平均 15.52%。灰分含量由大到小依次是污泥、粪污、秸秆、壳类和木质。秸秆生物炭灰分含量主要在 20%～35% 之间,较少为 15%;木质炭灰分主要在 0～10% 范围内。生物炭碳含量和灰分含量相关系数为–0.77。裂解温度与生物炭碳灰组分呈正相关,相关系数分别为 0.17 和 0.28。施入生物炭可以改善土壤状况,生物炭灰分通常对养分贫瘠土壤及沙质土壤的一些养分补充作用较明显。2）生物炭比表面积绝大多数在 0～520 m2/g 之间,平均 124.83 m2/g,壳类、秸秆、木质、粪污和污泥生物炭比表面积逐渐降低。秸秆炭比表面积集中在 0～200 m2/g 以内,木质炭比表面积集中在 0～100 m2/g 以内。制备温度与比表面积的相关系数为 0.48。生物炭的孔隙结构能降低土壤容重、降低土壤密度,能较好地去除溶液和钝化土壤中的重金属。3）生物炭 pH 值范围在 5～12,平均为 9.15。秸秆、污泥、粪污、木质、壳类生物炭 pH 值中值逐渐降低。秸秆生物炭 pH 值多集中在 8～11 范围内,木质生物炭 pH 相对一致。生物炭的 CEC 从 0 到 500 cmol /kg 都有分布,平均为 71.91 cmol/kg。秸秆类生物炭 CEC 值大多集中在 0～100 cmol/kg 范围内,木质生物炭则在 5～10 与 15～25 cmol/kg 范围内均有一定数量的分布。裂解温度与 pH 值和 CEC 的相关系数为 0.58 和 0.30。生物炭施入土壤后可消耗土壤质子,提高酸性土壤 pH 值,提高酸性土壤一些养分的有效性;其巨大的表面积还可提高对阳离子的吸附,提高土壤保肥能力。4）生物炭的裂解温度大都集中在 200～800℃ 之间,偶有达到 1000℃ 的裂解温度。 建议和展望 目前,全世界范围内对生物炭的生产和使用还处于就近和来源方便的初级阶段,影响着生物炭功能和效益的最大化。应从以下几个方面加强研究和应用试验:首先,系统研究生物炭制造参数对理化性状的影响,研究不同原料生物炭的作用机理差异及其针对性,建立生物炭理化性质参数数据库;其次,加强应用研究,根据土壤理化性状和改良目标选择适宜的生物炭类型,根据对作物经济性状的要求,研究选择适宜的生物炭类型,实现生物炭功效的最大利用。加强不同原料的选配和组合研究,改良生物炭产品的目标性状,形成系列化产品。      

生物炭和炭基肥在烟草农业的应用及展望

烟草是我国重要的经济作物,烟叶提质增效及绿色清洁生产是烟草农业绿色发展的必然趋势.烟秆炭化还田是实现烟秆资源化利用和环境友好发展的双赢途径.生物炭较大的比表面积、发达的孔隙结构、丰富的官能团、稳定的环状结构以及良好的吸附特性赋予其改良连作障碍烟田土壤、重建健康微生物生境的潜力.炭基肥融合了生物炭与肥料各自的优点,同时具...     

生物炭对土壤钾素生物有效性影响的研究进展

土壤缺钾已成为影响作物产量和品质,限制我国农业可持续发展的重要因素之一,亟待深入开展如何提高土壤钾素生物有效性的相关研究。本文收集整理了近年来研究者比较感兴趣的生物炭对土壤肥力,特别是对土壤钾素生物有效性影响的相关资料,从生物炭影响土壤温度、水分、p H值、阳离子交换量、微生物生物量与活性、作物根系生长与活动等方面论述了生物炭影响土壤钾素生物有效性的可能机理,并提出了今后需要深入研究的方面。     

生物炭陈化的研究进展

有关生物炭短期效应的研究已很多,然而对于生物炭长期效应的研究还缺乏理论基础,尤其是对于生物炭陈化的研究成果更少。综合国内外现有生物炭陈化研究成果,总结生物炭陈化方法,分析陈化处理对生物炭理化性质的影响,探索陈化生物炭施入对土壤性质的影响机制,阐明现有生物炭陈化研究方法的不足,提出未来生物炭陈化研究的发展方向,以期对生物炭陈化的研究具有参考意义。     

Effect of temperature on biochar priming effects and its stability in soils

Recent studies have shown both increased (positive priming) and decreased (negative priming) mineralisation of native soil organic carbon (SOC) with biochar addition. However, there is only limited understanding of biochar priming effects and its C mineralisation in contrasting soils at different temperatures, particularly over a longer period. To address this knowledge gap, two wood biochars (450 and 550 °C; δ¹³C −36.4‰) were incubated in four soils (Inceptisol, Entisol, Oxisol and Vertisol; δ¹³C −17.3 to −28.2‰) at 20, 40 and 60 °C in the laboratory. The proportions of biochar- and soil-derived CO₂–C were quantified using a two-pool C-isotopic model.Both biochars caused mainly positive priming of native SOC (up to +47 mg CO₂–C g⁻¹ SOC) in the Inceptisol and negative priming (up to −22 mg CO₂–C g⁻¹ SOC) in the other soils, which increased with increasing temperature from 20 to 40 °C. In general, positive or no priming occurred during the first few months, which remained positive in the Inceptisol, but shifted to negative priming with time in the other soils. The 550 °C biochar (cf. 450 °C) caused smaller positive priming in the Inceptisol or greater negative priming in the Entisol, Oxisol and Vertisol at 20 and 40 °C. At 60 °C, biochar caused positive priming of native SOC only in the first 6 months in the Inceptisol. Whereas, in the other soils, the native SOC mineralisation was increased (Entisol and Oxisol) and decreased (Vertisol) only after 6 months, relative to the control. At 20 °C, the mean residence time (MRT) of 450 °C and 550 °C biochars in the four soils ranged from 341 to 454 and 732−1061 years, respectively. At 40 and 60 °C, the MRT of both 450 °C biochar (25−134 years) and 550 °C biochar (93−451 years) decreased substantially across the four soils. Our results show that biochar causes positive priming in the clay-poor soil (Inceptisol) and negative priming in the clay-rich soils, particularly with biochar ageing at a higher incubation temperature (e.g. 40 °C) and for a high-temperature (550 °C) biochar. Furthermore, the 550 °C wood biochar has been shown to persist in soil over a century or more even at elevated temperatures (40 or 60 °C).     

Quantitative analysis of biochar in field soil

Biochar is used with increasing frequency as a soil amendment because of its potentially beneficial effects on soil carbon sequestration, crop yield, nutrient leaching and greenhouse gas emissions. Simple methods for the analysis of biochar in soil, however, are currently unavailable. Therefore, we have adapted the “loss on ignition” method for this purpose. The technique requires knowledge of the proportions of both biochar and biochar-free soil that are lost on ignition. One can use values determined prior to the amendment of the soil with biochar, assuming that the values do not change after biochar is incorporated in the soil. We tested these assumptions. Over the course of 15 months, the assumptions proved to be valid under our test conditions. The technique accurately determined a wide range of biochar concentrations in field soil.     

Effects of rice husk biochar on selected soil properties and nitrate leaching in loamy sand and clay soil

Biochar is a product of pyrolysis of biomass in the absence of oxygen and has a high potential to sequester carbon into more stable soil organic carbon (OC). Despite the large number of studies on biochar and soil properties, few studies have investigated the effects of biochar in contrasting soils. The current research was conducted to evaluate the effects of different biochar levels (0 (as control), 1% and 3%) on several soil physiochemical properties and nitrate leaching in two soil types (loamy sand and clay) under greenhouse conditions and wet-dry cycles. The experiment was performed using a randomized design with three levels of biochar produced from rice husks at 500 °C in three replications. Cation exchange capacity increased significantly, by 20% and 30% in 1% and 3% biochar-amended loamy sand soil, respectively, and increases were 9% and 19% in 1% and 3% biochar-amended clay soil, respectively. Loamy sand soil did not show improvement in aggregate indices, including mean weight diameter, geometric mean diameter, water stable aggregates and fractal dimension, which was contrary to the results for the clay soil. Rice husk biochar application at the both rates decreased nitrate leaching in the clay soil more than in the loamy sand. Our study highlights the importance of soil type in determining the value of biochar as a soil amendment to improve soil properties, particularly soil aggregation and reduced nitrate leaching. The benefits of the biochar in the clay soil were greater than in the loamy sand soil.     

生物质炭改良土壤及对作物效应的研究进展

生物质炭是作物秸秆等有机物质在限制供氧的条件下加热而成。生物质炭具有养分含量丰富、碱性和高稳定性等特点,因此可以降低土壤酸度,有效截留土壤养分,并在一定程度上促进养分吸收而提高作物产量。本文主要综述了生物质炭制备的影响因素及其施用后对土壤理化性质、作物生长发育和养分吸收等方面的影响。由于生物质炭在国内外的研究仍处于起步阶段,研究过程中所采取的方法、所用不同来源的生物质炭以及研究的具体对象等不尽相同,研究的结果显示生物质炭在某些方面的作用仍存在不同结论。目前,生物质炭的研究多集中在表面宏观现象上,对其深入的机理研究仍较欠缺,因此,需要科技工作者的进一步探索,文章最后阐述了未来对该领域研究的一些观点。     

The effect of young biochar on soil respiration

The low temperature pyrolysis of organic material produces biochar, a charcoal like substance. Biochar is being promoted as a soil amendment to enhance soil quality, it is also seen as a mechanism of long-term sequestration of carbon. Our experiments tested the hypothesis that biochar is inert in soil. However, we measured an increase in CO₂ production from soils after biochar amendment which increased with increasing rates of biochar. The ∂¹³C signature of the CO₂ evolved in the first several days of the incubation was the same as the ∂¹³C signature of the biochar, confirming that biochar contributed to the CO₂ flux. This effect diminished by day 6 of the incubation suggesting that most of the biochar C is slowly decomposing. Thus, aside from this short-term mineralization increasing soil C with young biochar may indeed be a long-term C storage mechanism.     

Sorption and desorption of phosphate on biochar and biochar–soil mixtures

The term biochar refers to materials with diverse chemical, physical and physicochemical characteristics that have potential as a soil amendment. The purpose of this study was to investigate the P sorption/desorption properties of various slow biochars and one fast pyrolysis biochar and to determine how a fast pyrolysis biochar influences these properties in a degraded tropical soil. The fast pyrolysis biochar was a mixture of three separate biochars: sawdust, elephant grass and sugar cane leaves. Three other biochars were made by slow pyrolysis from three Amazonian tree species (Lacre, Ingá and Embaúba) at three temperatures of formation (400 °C, 500 °C, 600 °C). Inorganic P was added to develop sorption curves and then desorbed to develop desorption curves for all biochar situations. For the slow pyrolysis, the 600 ºC biochar had a reduced capacity to sorb P (4–10 times less) relative to those biochars formed at 400 °C and 500 °C. Conversely, biochar from Ingá desorbed the most P. The fast pyrolysis biochar, when mixed with degraded tropical mineral soil, decreased the soil's P sorption capacity by 55% presumably because of the high soluble, inorganic P prevalent in this biochar (909 mg P/kg of biochar). Phosphorus desorption from the fast pyrolysis biochar/soil mixture not only exhibited a common desorption curve but also buffered the soil solution at a value of ca. 0.2 mg/L. This study shows the diversity in P chemistry that can be expected when biochar is a soil amendment and suggests the potential to develop biochars with properties to meet specific objectives.     

小麦秸秆生物炭对高氯代苯的吸附过程与机制研究

以小麦秸秆为原料,分别在三种温度(400℃、500℃、600℃)下制备小麦秸秆生物炭,并标记为WSB400、WSB500、WSB600。分析了秸秆炭的元素组成,表征了其结构和表面特征,研究了秸秆炭对五氯苯和六氯苯的吸附动力学和吸附等温线。结果表明,升温热解使得小麦秸秆有机组分炭化、极性官能团消除,炭化程度增强;三种秸秆炭均可快速高效地吸附高氯代苯,且对六氯苯的吸附要快于五氯苯,假二级动力学方程能更好地拟合秸秆炭对氯苯的吸附动力学过程;不同秸秆炭对氯苯的饱和吸附量大小顺序为WSB400WSB500WSB600;对吸附等温线进行分析可得,随着秸秆炭制备温度的升高,其对氯苯的吸附等温曲线由线性变为非线性,吸附机理则由以分配作用为主过渡到分配作用与表面吸附共同作用。     

不同温度玉米秸秆生物炭对萘的吸附动力学特征与机理

通过批平衡实验,研究不同剂量热解温度(300、400、500、600℃,记作C300、C400、C500、C600)玉米秸秆生物炭对萘的吸附动力学特征与机理。同一热解温度下生物炭投加剂量为10 mg时对萘的平衡吸附量大于50 mg。热解温度对生物炭吸附萘的影响也不同,投加剂量为10 mg时,萘的平衡吸附量为C400C300C600C500;剂量为50 mg时,C300、C400和C600的平衡吸附量相近,而C500的平衡吸附量最低。生物炭对萘的吸附动力学数据随时间的变化可以用假二级动力学方程很好地拟合,表明生物炭对萘的吸附是复杂的,并不是单一的单层吸附。用颗粒内扩散模型和Boyd模型分析,发现液膜扩散以及颗粒内扩散均影响吸附过程,且液膜扩散为限速因素。     

The priming potential of biochar products in relation to labile carbon contents and soil organic matter status

Recognition of biochar as a potential tool for long-term carbon sequestration with additional agronomic benefits is growing. However, the functionality of biochar in soil and the response of soils to biochar inputs are poorly understood. It has been suggested, for example, that biochar additions to soils could prime for the loss of native organic carbon, undermining its sequestration potential. This work examines the priming potential of biochar in the context of its own labile fraction and procedures for their assessment. A systematic set of biochar samples produced from C4 plant biomass under a range of pyrolysis process conditions were incubated in a C3 soil at three discrete levels of organic matter status (a result of contrasting long-term land management on a single site). The biochar samples were characterised for labile carbon content ex-situ and then added to each soil. Priming potential was determined by a comparison of CO₂ flux rates and its isotopic analysis for attribution of source. The results conclusively showed that while carbon mineralisation was often higher in biochar amended soil, this was due to rapid utilisation of a small labile component of biochar and that biochar did not prime for the loss of native organic soil organic matter. Furthermore, in some cases negative priming occurred, with lower carbon mineralisation in biochar amended soil, probably as a result of the stabilisation of labile soil carbon.