Changes in phosphorus fractions in three tropical soils amended with corn cob and rice husk biochars

ABSTRACT

The formation of phosphorus (P) compounds including iron-P, aluminum-P and calcium-P in highly weathered tropical soils can be altered upon biochar addition. We investigated the effect of corn cob biochar (CC) and rice husk biochar (RH) pyrolyzed at three temperatures (300°C, 450°C and 650°C) on phosphorus (P) fractions of three contrasting soils. A 90d incubation study was conducted by mixing biochar with soil at a rate of 1% w/w and at 70% field capacity. Sequential P fraction was performed on biochar, soil and soil-biochar mixtures. Increase in most labile P (resin-P_i, NaHCO₃-P_i) and organic P fraction (NaHCO₃-P_o + NaOH-P_o) in CC and RH biochars were inversely related to increasing temperature. HCl-P_i and residual P increased with increasing temperature. Interaction of CC and RH with soils resulted in an increase in most labile P as well as moderately labile P (NaOH-P_i) fractions in the soils. CC increased most labile P in the soils more than RH. The increase in most labile P fraction in soils was more significant at relatively lower temperatures (300°C and 450°C) than 650°C. However, the increase in HCl-P_i and residual P of the soils was more predominant at high temperature (650°C). The study suggested that biochar pyrolyzed at 300–450°C could be used to increase P bioavailability in tropical soils.     

生物炭和其他有机土壤改良剂对Ustoxic Quartzipsamment土壤上植物养分有效性的影响

A sandy soil, Nampong soil(classified as Ustoxic Quartzipsamment), was incubated under controlled condition i) to compare the mineralization of major plant nutrients derived from different types of biochars and other organic soil amendments; ii) to examine their effects on soil properties and plant nutrient availability; and iii) to evaluate the plant nutrient losses in leachate from the rooting zone of soil incorporated with the different amendments. The experiment was arranged in a completely randomized design with 3 replications.Five treatments of soil amendments used were cassava stem base biochar(CSB), rice husk biochar(RHB), chicken manure(CM),compost(CP), and no amendment application(control). The RHB treatment released the highest amounts of mineralized NO-3-N,available P and K(2.30–17.26, 5.50–42.90 and 43.00–187.63 mg kg-1, respectively) while the CM treatment releasing the highest NH+4-N in the range of 1.86–53.67 mg kg-1. The CSB and RHB treatments showed better continuity of mineralization of nutrients than the treatments of CM and CP, particularly in the case of the CSB treatment. In the soil column incubation experiment, the amounts of NH+4-N and NO-3-N in all treatments barely changed on Day 1 to Day 30 of incubation and then the amounts increased markedly on Day 60. On Day 60, the RHB treatment contained a very high amount of NO-3-N( 250 mg kg-1). This suggests that N would become more available 30 d after the incorporation. The CM treatment gave the highest amounts of organic matter and available P in the ranges of 4.64–8.94 g kg-1and 14.41–36.33 mg kg-1, respectively, during the 60-d column incubation. The CSB treatment tended to have higher available K throughout the measuring period. The NO-3-N was leached from the soil column quite quickly on Day 1 of incubation while the loss of NH+4-N decreased slightly from Day 1 until the end of the measurement. The amounts of P and K losses varied with the type of soil amendments, and the pattern of the loss was irregular.     

凹凸棒土-生物炭缓释材料对养分缓释及小白菜生长的影响

为解决化肥径流淋洗及养分挥发损失量大、养分释放难与作物吸收同步等问题,该研究对天然缓释材料凹凸棒土进行了300℃热改性处理,同时与生物炭相结合,制备了热改性凹凸棒土-生物炭复合材料,以期提升该材料对氮磷钾养分的缓释性能,并以小白菜进行生物效应验证。试验共设7个处理：以不施肥（CK）和普通化肥（F）做对照,设置化肥+凹凸棒土（AF）、化肥+热改性凹凸棒土（TAF）、化肥+生物炭（BF）、化肥+凹凸棒土+生物炭（ABF）、化肥+热改性凹凸棒土+生物炭（TABF）缓释。结果表明：1）天然凹凸棒土经300℃热改性后,呈现破碎及圆形塌陷结构并出现大量的间隙和裂缝,为养分离子与复合材料相互作用提供更多位点,从而对氮磷钾元素呈现出较优的吸附性能。2）相比生物炭,热改性凹凸棒土+生物炭复合材料由片层转变为疏松多孔结构,具有更多孔道和较深的孔径;同时SiO₂、MgFe₄(SO₄)₆(OH)₂(H₂O)₂₀和CaMg(CO₃)₂含氧基团增加,提高了复合缓释材料吸附效果。3）与普通化肥（F）氮、磷养分释放高峰在第5天和第9天相比,TABF则出现在第52天和第42天,缓释效果突出。4）TABF代替化肥后,可与小白菜整个生育期对养分需求同步缓释,在表型指标、品质、产量等方面均优于CK和F处理;与普通化肥相比,5种缓释材料均能显著增加氮磷钾利用率和农学效率,其中以TABF最优。综上所述：300℃热改性显著增加了凹凸棒土的吸附位点,特别是凹凸棒土-生物炭复合材料更能有效提高肥料的缓释性能,与小白菜全生育期的养分需求同步性好,有效提高了氮磷钾利用率。     

大型海藻基生物炭中多环芳烃分布特征及毒性评价

研究大型海藻基生物炭中多环芳烃（Polycyclic Aromatic Hydrocarbons,PAHs）分布特征及毒性可为其资源化利用提供重要的依据。该研究利用索氏提取结合气相色谱质谱法分析了不同热解温度（200、300、400、500和600 ℃）的大型海藻（瓦氏马尾藻（Sagassum vachellianum）、羊栖菜（Sargassum fusiforme）、鼠尾藻（Sargassum thunbergii）、带形蜈蚣藻（Grateloupia turuturu）、粗枝软骨藻（Chondria crassicaulis）及孔石莼（Ulva pertusa））基生物炭中16种PAHs含量并对其毒性进行评价。结果表明,大型海藻基生物炭中均能检出PAHs（总量浓度为78.2～2 244.2 μg/kg）,且其生成量整体随热解温度升高先增加后降低。大型海藻基生物炭中PAHs含量均低于欧洲生物炭标准（European Biochar Certificate,EBC,10.1版）规定的EBC-AgroOrganic等级限量值（4±2）mg/kg。大型海藻基生物炭中PAHs以2环和3环为主,4环PAHs在所有生物炭中均存在,而5环和6环PAHs仅在部分生物炭中被检出。此外,不同大型海藻基生物炭呈现各异的苯并[a]芘毒性当量浓度（BaP- Toxic Equivalence Quantity, TEQBaP）（0.196～46.151 μg/kg）,其TEQBaP不仅依赖于生物炭中PAHs含量还与其环数和类型分布有关。在生物炭修复效果且潜在环境风险相近的基础上,结合产率及热解温度耗能,可选择热解温度较低的生物炭材料,为大型海藻基生物炭制备与应用的优化提供重要指导。     

Chemical fractions and bioavailability of nickel in a Ni-treated calcareous soil amended with plant residue biochars

ABSTRACT

Recently, the use of biochars for stabilization of soil heavy metals has been expanded due to their adsorption characteristics, low cost and carbon storage potential. A factorial experiment was performed to investigate the effects of two plant residue biochars (licorice root pulp and rice husk biochar each applied at 2.5% (w/w)) produced at two temperatures (350 and 550 °C), and three Ni application rates (0, 150 and 300 mg Ni kg^?1) on bioavailability and chemical fractions of Ni in a calcareous soil after spinach cultivation. Application of all the biochars significantly reduced Ni bioavailability factor (5–15%) and spinach Ni concentration (54–77%) in Ni-treated soil. The biochars produced at 550 °C were more effective at reducing Ni mobility and Ni uptake by spinach than those produced at 350 °C, attributed to higher CaCO₃ and lower acidic functional group content, which resulted in greater enhancement of soil pH. When comparing the biochars produced at the same temperature, the rice husk biochars were the most effective in reducing Ni bioavailability, likely due to their lower acidic functional group content and higher nano-silica content which resulted in higher soil pH values and potentially promoted the formation of Ni-silicates and hydroxides.

Abbreviations : Ni: Nickel; RHB: rice husk biochar; LRB: licorice root pulp biochar; WsEx: water soluble and exchangeable; CARB: carbonate form; RES: residual; MnOx; manganese oxides bound; AFeOx; amorphous iron oxides bound; CFeOx: crystalline iron oxides bound; OM: organic bound.     

Sugarcane yield and plant nutrient response to sulfur-amended Everglades histosols

High soil pH causes leaf nutrient deficiencies and reduces sugarcane yield. Soil pH in Florida histosols has been increasing as these soils subside and depth to limestone is decreased. A factorial experiment of four sulfur (S) rates and three added calcium carbonate (CaCO₃) levels in soil was designed to determine S-amendment effectiveness in reducing pH and increasing nutrient availability in sugarcane as calcium (Ca) carbonate levels were increased. Sulfur-amendment and increased CaCO₃ level had limited effects on yield and leaf nutrient concentrations during the growing season. Most leaf nutrients were within optimum range except nitrogen (N), phosphorus (P), iron (Fe), and manganese (Mn). Unexpected increases in Mn concentrations with added CaCO₃ were associated with reducing conditions due to increased soil bulk density. High soil pH caused Mn deficiencies in the plants. Soil pH, P and Mn concentrations were important factors in predicting sugarcane yield.     

Effects of biochars produced from different feedstocks on soil properties and sunflower growth

The use of biochar as a soil amendment is gaining interest to mitigate climate change and improve soil fertility and crop productivity. However, studies to date show a great variability in the results depending on raw materials and pyrolysis conditions, soil characteristics, and plant species. In this study, we evaluated the effects of biochars produced from five agricultural and forestry wastes on the properties of an organic‐C‐poor, slightly acidic, and loamy sand soil and on sunflower (Helianthus annuus L.) growth. The addition of biochar, especially at high application rates, decreased soil bulk density and increased soil field capacity, which should impact positively on plant growth and water economy. Furthermore, biochar addition to soil increased dissolved organic C (wheat‐straw and olive‐tree‐pruning biochars), available P (wheat‐straw biochar), and seed germination, and decreased soil nitrate concentration in all cases. The effects of biochar addition on plant dry biomass were greatly dependent upon the biochar‐application rate and biochar type, mainly associated to its nutrient content due to the low fertility of the soil used. As a result, the addition of ash‐rich biochars (produced from wheat straw and olive‐tree pruning) increased total plant dry biomass. On the other hand, the addition of biochar increased the leaf biomass allocation and decreased the stem biomass allocation. Therefore, biochar can improve soil properties and increase crop production with a consequent benefit to agriculture. However, the use of biochar as an amendment to agricultural soils should take into account its high heterogeneity, particularly in terms of nutrient availability.     

高含氮木质废弃物热解气化特性研究

为了考察高含氮木质废弃物的气化特性,在热重-质谱-红外联用装置与固定床装置上进行了Ar和Ar+O2气氛下高含氮木质废弃物和木粉的热解气化试验,研究了2种原料热解气化过程和产物的异同。结果表明:2种原料的热解气化失质量和失质量速率曲线整体一致,阶段划分较为类似,但高含氮木质废弃物挥发分析出峰值出现的温度低于木粉15～20℃,失质量速率峰值为木粉的70%左右;2种原料热解气化产物主要成分整体上较为类似,但高含氮木质废弃物热解气化产物中CH4浓度明显高于木粉;高含氮木质废弃物气化产生含氮气体污染物高于木粉,固定床试验中产生的NH3浓度为木粉的147倍。该文结果可为高含氮木质废弃物的处理和高效资源化利用提供参考依据。     

Effect of wheat and rice straw biochar produced at different temperatures on maize growth and nutrient dynamics of a calcareous soil

The objective of this work was to study the effect of different biochar on alkaline calcareous soil, inherently low in soil organic carbon and fertility. Experiments were conducted in laboratory and greenhouse. Biochar was produced from wheat and rice straws at pyrolysis temperatures of 300°C, 400°C and 500°C (denoted as WSB300, WSB400, WSB500, RSB300, RSB400 and RSB500, respectively). In the first experiment, soil was incubated with biochar (1.0 % w/w) for up to 50 weeks. The results indicate that, WSB300 caused a significant decrease in soil pH and increased the CEC and nutrients (N, P and K) after 50 weeks of incubation. In the second experiment, maize plants were grown in pots containing calcareous soil amended with WSB and RSB for 60 days the results revealed that the application of WSB300 caused a significant increase in shoot (36%) and root (38%) dry matters over the respective control. Moreover, the highest nutrient concentrations (N and P) in shoot and root were observed with the WSB300 compared to other treatments. Therefore, it is concluded that application of wheat straw biochar produced at low temperature (WSB300) could be successfully used to improve soil properties and growth of plants in calcareous soils.     

生物炭对夏玉米农田土壤有效养分垂直分布及作物利用的影响

生物炭具有改良耕层土壤理化性质和保水保肥的功效.针对华北地区农田养分利用效率低的问题,采用田间试验方法,研究了生物炭不同施用量对夏玉米生长关键期0～100 cm土壤有效态氮、磷、钾垂直分布特征及其对作物养分吸收利用的影响.试验设B0F(0 t/hm2生物炭+化肥)、B5F(5 t/hm2生物炭+化肥)、B10F(10 ...     

Carbon potentials of different biochars derived from municipal solid waste in a saline soil

There are numerous studies conducted on biochar for its carbon (C) sequestration potential;however,there are limited studies available on the behavior of salt-affected soils related to biochar application.Therefore,more studies are needed to elucidate the mechanisms through which biochar affects saline soil properties.In this study,biochars were produced from solid waste at pyrolysis temperatures of 300,500,and 700?C (BC300,BC500,and BC700,respectively)and applied to a saline soil to evaluate their impacts on soil carbon dioxide (CO₂) efflux,C sequestration,and soil quality.A soil incubation experiment lasting for 107 d was conducted.The results showed that soil CO₂ efflux rate,cumulative CO₂ emission,active organic C (AOC),and organic matter (OM)significantly increased with BC300 application to a greater extent than those with BC500 and BC700 as compared to those in the no-biochar control (CK).However,soil C non-lability did not significantly increase in the treatments with biochars,except BC700,as compared to that in CK.Besides improving the soil quality by increasing the soil AOC and OM,BC300 showed positive impacts in terms of increasing CO₂ emission from the saline soil,while BC500 and BC700 showed greater potentials of sequestering C in the saline soil by increasing the soil non-labile C fraction.The recalcitrance index (R50) values of BC500 and BC700 were>0.8,indicating their high stability in the saline soil.It could be concluded that biochars pyrolyzed at high temperatures (?500?C)could be suitable in terms of C sequestration,while biochars pyrolyzed at low temperatures (?300?C) could be suitable for improving saline soil quality.     

热带农业生态系统土壤肥力与植物养分综合管理研究进展

The greatest challenge for tropical agriculture is land degradation and reduction in soil fertility for sustainable crop and livestock production.Associated problems include soil erosion,nutrient mining,competition for biomass for multiple uses,limited application of inorganic fertilizers,and limited capacity of farmers to recognize the decline in soil quality and its consequences on productivity.Integrated soil fertility management(ISFM) is an approach to improve crop yields,while preserving sustainable and long-term soil fertility through the combined judicious use of fertilizers,recycled organic resources,responsive crop varieties,and improved agronomic practices,which minimize nutrient losses and improve the nutrient-use efficiency of crops.Soil fertility and nutrient management studies in Ethiopia under on-station and on-farm conditions showed that the combined application of inorganic and organic fertilizers significantly increased crop yields compared to either alone in tropical agro-ecosystems.Yield benefits were more apparent when fertilizer application was accompanied by crop rotation,green manuring,or crop residue management.The combination of manure and NP fertilizer could increase wheat and faba bean grain yields by 50%–100%,whereas crop rotation with grain legumes could increase cereal grain yields by up to 200%.Although organic residues are key inputs for soil fertility management,about 85% of these residues is used for livestock feed and energy;thus,there is a need for increasing crop biomass.The main incentive for farmers to adopt ISFM practices is economic benefits.The success of ISFM also depends on research and development institutions to provide technical support,technology adoption,information dissemination,and creation of market incentives for farmers in tropical agro-ecosystems.     

Variations of nutrient concentrations and contents between summer and autumn within tree compartments of European beech (Fagus sylvatica)

The paradigm of sustainable forest management was initially aimed to ensure continuous wood supply but has gradually been extended for many functions and services of forest ecosystems, including the aspect of nutrient sustainability. The current tendency towards harvesting all year round and whole‐tree export for energy purposes raised the question of how the input : output balance of nutrients depends on site conditions, tree species, and harvest intensity. Possible differences in nutrient export between harvesting in autumn and summer have been more or less neglected. Based on compartment‐wise analyses of biomass and nutrient (Ca, K, Mg, and P) concentrations of adult European beeches (Fagus sylvatica [L.]), nine compartments were sampled in summer and nine in autumn. We found, for the majority of the compartments (especially in branch wood), increased levels of nutrient concentrations: 81% (Ca), 54% (K), 90% (Mg), and 96% (P) in autumn compared to summer. Upscaling our results to stand level revealed up to 10.0% and 1.6% less mineral nutrient exports of Ca and Mg, respectively, for whole‐tree harvest in forest stands when carried out in summer instead of autumn. Nutrient removal was increased by 0.8% and by 13.0% for K and P, respectively, in summer. Despite lower nutrient export, many ecological, logistic, and technical reasons discourage harvesting in summer. Our findings, however, deliver an additional yet so far missing mosaic piece for a better understanding and assessment of the frame conditions for sustainable nutrient management in beech forests.     

车用生物燃气工程范例余热定量评估及可利用性分析

针对车用生物燃气工程能耗高、余热利用率低的问题,该文以国内4个典型工程为基础,构建了产气规模为1万m3/d的示例工程,并对其进行余热分析。分析结果显示,此类工程用能量大,占总产能的30.01%～36.44%;余热利用率低,只有部分贫液余热得以回收;系统余热主要由脱碳塔顶气余热、脱碳贫液余热、压缩机余热、沼液余热和锅炉尾气余热5部分组成,其多为低品位余热、量大稳定。余热计算表明,在最冷月和最热月系统余热潜力分别为5.87×104、4.79×104 MJ/d,最大节能潜力分别为74.81%和73.92%,节能潜力降序排列为沼液余热>贫液余热>塔顶气余热>压缩机余热>锅炉余热。余热可利用性分析认为工程余热可利用性较高,回收价值较大。     

绿化植物废弃物堆肥对城市绿地土壤的改良效果

针对城市中普遍存在的绿地土壤退化和有机废弃物处理处置难的现状,选择典型城市土壤进行绿化植物废弃物堆肥不同用量的绿地现场土壤改良实验.结果表明:绿化植物废弃物堆肥能提高土壤持水能力;降低土壤的酸碱度;增加土壤有机质、总N、总P、有效P、生物量C、N和微生物总量;堆肥对土壤全K的含量总体影响不大,但速效K的含量却成倍增加;说明绿化植物废弃物能改善土壤理化性质,提高土壤肥力,且随着堆肥用量的增加,对土壤的改良作用也越显著;鉴于绿化植物废弃物高C/N,其用量宜控制在13240 kg/hm~2以内.绿化植物废弃物堆肥就地利用即能改良城市退化土壤,又减少城市废弃物量,有利于提高城市生态环境质量.     

农业废弃物对黑土有机磷形态长期动态影响

针对农业废弃物在土壤中腐解时间较长,探究增施不同种类农业废弃物对黑土土壤各形态有机磷影响的长期动态变化规律,开展5a盆栽试验并根据Bowman-Cole法测定有机磷形态。试验设置5个处理,分别为:增施猪粪、秸秆、树叶、菌渣和单施化肥。结果表明:与单施化肥相比,增施猪粪可大幅提高土壤活性有机磷(L-OP)含量,5a时仍显著高于单施化肥;增施秸秆和树叶分别于3a和2a后出现最高值。增施猪粪、秸秆和菌渣后土壤中等活性有机磷(ML-OP)含量显著增加;猪粪处理ML-OP含量逐年降低,其余处理逐年上升。增施农业废弃物均可显著增加土壤中稳态有机磷(MR-OP)含量,总体呈逐年降低趋势;增施秸秆5a内MR-OP含量始终最高。增施农业废弃物对土壤高稳性有机磷(HR-OP)含量的降低作用一般在2~3a后开始显现,5a后HR-OP含量均低于单施化肥。增施猪粪可大幅提高活性较强的有机磷形态且影响时间最长;增施秸秆和菌渣变化趋势相似,增施秸秆更趋向于增加L-OP和MR-OP含量,增施菌渣更趋向于增加HR-OP含量;增施树叶降低HR-OP含量能力最强,但对其余有机磷形态影响较小。施用农业废弃物均可不同程度活化稳定态有机磷,单施化肥处理促使中稳态有机磷向高稳态有机磷转化。     

煤矸石山废弃地不同植物复垦措施及其对土壤化学性质的影响

 为了筛选出适合煤矸石山废弃地的造林树种和复垦措施,在辽宁省抚顺市,初步研究了不同植物复垦措施对煤矸石山废弃地土壤化学性质和植物生长的影响。结果表明:不同供试植物在煤矸石山废弃地的成活率在21%～85%之间,其中白榆和沙打旺的成活率分别为81%和85%,而小叶杨、刺槐、栾树的成活率均在70%左右,这些植物均适合于在煤矸石山废弃地生长。植物措施能明显提高煤矸石山废弃地不同土层的有机质、全N、全P和全K含量,但提高程度随土壤层厚度和养分种类而不同。在植物复垦中,配合应用生物复合肥料、生物菌剂和保水剂,能改善主要造林树种的生长状况。     

城市固体废弃物堆肥与化肥对不同土壤植物生长的影响研究

温室盆栽试验研究城市固体废弃物堆肥与化肥对不同土壤黑麦草生长的影响,结果表明,堆肥和化肥可明显增加黑麦草干物质产量,阳春和大安2种土壤处理C50干物质产量分别比对照增加39.53%和109.38%,而NPK处理则分别增产267.44%和406.25%。堆肥与化肥配施处理(NPK C25对阳春和NPK C50对大安)产量最高。堆肥处理明显增加土壤pH、有机碳、土壤有效态磷、钾、铁、锰、锌和铜含量。     

啤酒花中矿物元素在生长期的动态变化研究

利用电感耦合等离子体-质谱(ICP-MS)和电感耦合等离子体-发射光谱(ICP-OES)对不同种植地的青岛大花、札一和马可波罗3个新疆主产啤酒花品种中的22种矿物元素在生长期的含量进行跟踪测定。结果表明,啤酒花对矿物元素的吸收和积累存在"地域差异"和"时间差异",其中Sr、Na、Rb、Li、Ba、Ga、Co和V的含量受种植地的影响较大;但在整个生长周期内,啤酒花对重金属无明显吸收和富集作用。基于22种元素的主成分分析结果进一步证实,前3个主成分的累计贡献率达到84.36%,且由PC 1和PC 2构成的得分散点图可以很好地区分不同产地的啤酒花样本;而由PC 1和PC 3组成的得分散点图主要可以区分啤酒花的"成熟度"。其中,Mg、K、Li、Na可以用来判别啤酒花的产区;Al、Pb、V对于评价啤酒花的成熟度具有较大价值。     

富含磁性铁纳米颗粒的生物炭对菌根侵染、植物生长、营养吸收及土壤质量改善的影响

At present, there is little commercial sale of biochar, since farmers find they can not gain a return on their investment in this amendment in the first few years after its application, because of the high cost associated with large application rates. To overcome this constraint, development of artificially aged enriched biochar-mineral complexes (BMCs), having a higher mineral content, surface functionality, exchangeable cations, high concentration of magnetic iron (Fe) nanoparticles, and higher water-extractable organic compounds has been undertaken by a combined team of researchers and a commercial company.~% Two biochars produced under different pyrolysis conditions were activated with a phosphoric acid treatment. A mixture of clay, chicken litter, and minerals were added to the biochar, and then this composite was torrefied at either 180 or 220 $^\circ$C. In this study a pot experiment was carried out in glasshouse conditions to determine the effects of four different BMCs, with different formulations applied at rates of 100 and 200 kg ha$^{-1}$, on the mycorrhizal colonisation, wheat growth and nutrient uptake, and soil quality improvement. It was found that the phosphorus (P) and nitrogen uptake in wheat shoots were significantly greater for a low application rate of BMCs (100 kg ha$^{-1}$).~The present formulation of BMC was effective in enhancing growth of wheat at low application rate (100 kg ha$^{-1}$).~The increase in growth appeared due to an increase in P uptake in the plants that could be partly attributed to an increase in mycorrhizal colonisation and partly due to the properties of the BMC.