The amelioration effects of low temperature biochar generated from nine crop residues on an acidic Ultisol

Biochar was prepared using a low temperature pyrolysis method from nine plant materials including non‐leguminous straw from canola, wheat, corn, rice and rice hull and leguminous straw from soybean, peanut, faba bean and mung bean. Soil pH increased during incubation of the soil with all nine biochar samples added at 10 g/kg. The biochar from legume materials resulted in greater increases in soil pH than from non‐legume materials. The addition of biochar also increased exchangeable base cations, effective cation exchange capacity, and base saturation, whereas soil exchangeable Al and exchangeable acidity decreased as expected. The liming effects of the biochar samples on soil acidity correlated with alkalinity with a close linear correlation between soil pH and biochar alkalinity (R² = 0.95). Therefore, biochar alkalinity is a key factor in controlling the liming effect on acid soils. The incorporation of biochar from crop residues, especially from leguminous plants, can both correct soil acidity and improve soil fertility.     

Use of agricultural by-products to study the pH effects in an acid tea garden soil

The amelioration of an acid Alfisol from a tea garden was studied by incorporating various plant materials: canola straw, wheat straw, rice straw, corn straw, soybean straw, peanut straw, faba bean straw, Chinese milk vetch shoot and pea straw prior to incubation for a maximum of 65 days. Soil pH increased after incubation with all the incorporated materials with the legumes causing the largest increases. The final soil pH was correlated with ash alkalinity ( r ² = 0.73), base cations ( r ² = 0.74) and N content ( r ² = 0.93) of the applied materials. It was assumed that the incubation released the base cations in plant materials as they decomposed which ultimately increased the base cation saturation of the soil. Similarly, soil exchangeable Al was also decreased with the incorporation of the legume plant materials and corn straw and rice straw. Our investigation demonstrated that legumes are the preferred choice for controlling the soil acidity and also for reducing the toxicity of Al in acid soils.     

复配改良剂表施对高降雨量地区茶园底层强酸性土壤酸度的调控

Strongly acidic soils (pH < 5.0) are detrimental to tea (Camellia sinensis) production and quality. Little information exists on the ability of surface amendments to ameliorate subsoil acidity in the tea garden soils. A 120-d glasshouse column leaching experiment was conducted using commonly available soil ameliorants. Alkaline slag (AS) and organic residues, pig manure (PM) and rapeseed cake (RC) differing in ash alkalinity and C/N ratio were incorporated alone and in combination into the surface (0--15 cm) of soil columns (10 cm internal diameter × 50 cm long) packed with soil from the acidic soil layer (15--30 cm) of an Ultisol (initial pH = 4.4). During the 120-d experiment, the soil columns were watered (about 127 mm over 9 applications) according to the long-term mean annual rainfall (1 143 mm) and the leachates were collected and analyzed. At the end of the experiment, soil columns were partitioned into various depths and the chemical properties of soil were measured. The PM with a higher C/N ratio increased subsoil pH, whereas the RC with a lower C/N ratio decreased subsoil pH. However, combined amendments had a greater ability to reduce subsoil acidity than either of the amendments alone. The increases in pH of the subsoil were mainly ascribed to decreased base cation concentrations and the decomposition of organic anions present in dissolved organic carbon (DOC) and immobilization of nitrate that had been leached down from the amended layer. A significant (P < 0.05) correlation between alkalinity production (reduced exchangeable acidity -- N-cycle alkalinity) and alkalinity balance (net alkalinity production -- N-cycle alkalinity) was observed at the end of the experiment. Additionally, combined amendments significantly increased (P < 0.05) subsoil cation concentrations and decreased subsoil Al saturation (P < 0.05). Combined applications of AS with organic amendments to surface soils are effective in reducing subsoil acidity in high-rainfall areas. Further investigations under field conditions and over longer timeframes are needed to fully understand their practical effectiveness in ameliorating acidity of deeper soil layers under naturally occurring leaching regimes.     

碱渣与菜籽饼共施对茶园土壤酸度调控的研究

Rapeseed cake (RC), the residue of rapeseed oil extraction, is effective for improving tea (Camellia sinensis) quality, especially taste and aroma, but it has limited ability to ameliorate strongly acidic soil. In order to improve the liming potential of RC, alkaline slag (AS), the by-product of recovery of sodium carbonate, was incorporated. Combined effects of different levels of RC and AS on ameliorating acidic soil from a tea garden were investigated. Laboratory incubations showed that combined use of AS and RC was an effective method to reduce soil exchangeable acidity and Al saturation and increase base saturation, but not necessarily for soil pH adjustment. The release of alkalinity from the combined amendments and the mineralization of organic nitrogen increased soil pH initially, but then soil pH decreased due to nitrifications. Various degrees of nitrification were correlated with the interaction of different Ca levels, pH and N contents. When RC was applied at low levels, high Ca levels from AS repressed soil nitrification, resulting in smaller pH fluctuations. In contrast, high AS stimulated soil nitrification, when RC was applied at high levels, and resulted in a large pH decrease. Based on the optimum pH for tea production and quality, high ratios of AS to RC were indicated for soil acidity amelioration, and 8.0 g kg-1 and less than 2.5 g kg-1 were indicated for AS and RC, respectively. Further, field studies are needed to investigate the variables of combined amendments.     

Use of crop residues with alkaline slag to ameliorate soil acidity in an Ultisol

Information regarding the interaction between liming agents and crop residues on soil acidity amelioration is limited. A laboratory incubation study was undertaken to investigate the combined application of alkaline slag (AS, the major component is CaO) and crop residues with different C/N ratios and ash alkalinity content. Incorporation of amendments was effective in reducing soil exchangeable acidity and Al saturation and increasing exchangeable base cations (P < 0.05), but the effect of AS on soil pH adjustment was reduced when added with a high amount of residue with a low C/N ratio. Initial increases in soil pH were attributed to the release of alkalinity from the combined amendments and the mineralization of organic nitrogen (N). During subsequent incubation, the soil pH decreased because of nitrification. Crop residues with a high C/N ratio increased N immobilization and reduced net nitrification, resulting in a slight pH decrease. Crop residues with a low C/N ratio resulted in a sharp decrease in soil pH when applied with low levels of AS because of stimulated soil nitrification, whereas high AS had no consistent effect on net nitrification. Hence, compared to the control (pH = 4.21), a large increase in soil pH occurred, especially when peanut straw was applied at 10 g/kg (pH = 5.16). It is suggested that crop residues with high C/N ratio and also combined with a liming agent such as AS are preferred to ameliorate soil acidity. The liming effect of AS is likely to be negated if added in combination with residues with high N contents.     

生物质炭对茶园土壤改良及茶叶品质的影响

近年来,茶树种植过程中化肥的超量施用造成茶园土壤酸化加剧和有机质含量降低等一系列问题,进而影响到茶叶的产量和品质。生物质炭一般呈碱性,具有含碳量高、比表面积大、高度生物化学稳定性和较强的吸附性能等特性,能够增加土壤碳储量,提高土壤pH值和养分有效性,对于茶园土壤固碳、土壤改良和抑制土壤氮磷流失、改善农产品品质等方面有较大作用。针对我国茶园土壤存在的主要问题,以生物质炭的特性及生物质炭改良土壤的作用机理为研究对象,重点阐述了生物质炭在茶园酸化土壤改良、土壤氮素淋失阻控、土壤固碳增汇等方面的效应,以及生物质炭提高茶叶产量和提升茶叶品质方面的作用机理。基于以上研究,展望了生物质炭在茶园管理方面的理论研究方向,为生物质炭在农业生产中的应用和推广提供科学依据。     

糠醛残留物对控制土壤碱化及碱土改良的影响

Furfural residue, an industrial waste, is a kind of strongly acidic organic materials. Its comprehensive utilization in agriculture showed a significant effect on control of soil alkalization, amelioration of solonetz and increase of crop yields. In detail it may adjust pH, depress alkalinity, reduce bulk density and compactness and increase water permeability and retention ability of the soil. Meanwhile agricultural use of furfural residue provided an effective way to avoid its pollution of the soil, water and air.     

通过施用碱性矿渣和作物残茬生物炭以促进酸性老成土中盐基饱并降低土壤酸度

This investigation was conducted by using alkaline slag and crop straw biochars to reduce acidity of an acidic Ultisol through incubation and pot experiments with lime as a comparison. The soil was amended with different liming materials： lime（1 g kg^-1）,alkaline slag（2 and 4 g kg^-1）, peanut straw biochar（10 and 20 g kg^-1）, canola straw biochar（10 and 20 g kg^-1） and combinations of alkaline slag（2 g kg^-1） and biochars（10 g kg^-1） in the incubation study. A pot experiment was also conducted to observe the soybean growth responses to the above treatments. The results showed that all the liming materials increased soil p H and decreased soil exchangeable acidity. The higher the rates of alkaline slag, biochars, and alkaline slag combined with biochars, the greater the increase in soil p H and the reduction in soil exchangeable acidity. All the amendments increased the levels of one or more soil exchangeable base cations. The lime treatment increased soil exchangeable Ca^2＋, the alkaline slag treatment increased exchangeable Ca^2＋ and Mg^2＋ levels, and the biochars and combined applications of alkaline slag with biochars increased soil exchangeable Ca^2＋, Mg^2＋ and K^＋ and soil available P. The amendments enhanced the uptake of one or more nutrients of N, P, K, Ca and Mg by soybean in the pot experiment. Of the different amendments, the combined application of alkaline slag with crop straw biochars was the best choice for increasing base saturation and reducing soil acidity of the acidic Ultisol. The combined application of alkaline slag with biochars led to the greatest reduction in soil acidity, increased soil Ca, Mg, K and P levels, and enhanced the uptake of Ca, Mg, K and P by soybean plants.     

三种植物物料对两种茶园土壤酸度的改良效果

用室内培养实验研究了稻草、花生秸秆和紫云英在 5、10 和 20 g/kg 的加入量水平下对茶园黄棕壤和茶园红壤酸度的改良效果.结果表明:除了黄棕壤加入紫云英处理会降低土壤的 pH 外,其余所有加入植物物料的处理均使土壤 pH 有不同程度的增加,使土壤交换性酸和交换性Al的数量减小,使土壤交换性盐基阳离子和盐基饱和度增加.有机物料对土壤酸度的改良效果与有机物料灰化碱和N含量有关,灰化碱和有机N的矿化使土壤 pH 升高,NH4+-N的硝化使土壤 pH 降低.3种植物物料中花生秸秆对土壤酸度的改良效果优于紫云英和稻草.加入植物物料使红壤中有毒形态Al的浓度显著减小,说明植物物料能够缓解红壤中Al对植物的毒害.     

Effect of the amelioration of soil acidity and continuous cropping of cruciferous vegetables on the incidence of clubroot disease and resting spore density in soil

pp. 891–896

In order to elucidate the effect of converter furnace slag applied as a liming amendment and continuous cropping of Qing gin cai (Brassicae chinensis L.) or leaf daikon (Raphanus sativus) on the incidence of clubroot disease and the resting spore density in soil, pot cultivation tests were carried out. In the pot tests, pH(H₂O) was 5.2–6.1 in the non-application pot, and 7.1–7.6 in the pots receiving an application of converter furnace slag.

A significant incidence of club-root disease was apparent in the non-application pots of Qing gin cai. The resting spore density in the soils decreased soon after harvesting, but then increased after mixing the infected roots and soils.

On the other hand, the incidence of the disease was suppressed significantly, in application pots of continuously cropped Qing gin cai. Furthermore, the resting spore density in these soils decreased with repeated cultivation.

These results agreed well with the results from field cultivation tests that the authors have already reported. Macfarlane has reported that the suppression mechanism of clubroot disease brought about by the amelioration of soil acidity is effected through the inhibition of resting spore germination.

In this study, the decrease of resting spores density was associated with the cultivation of Qing gin cai under conditions of high soil pH. From these results, it is concluded that the suppression mechanism is caused by some phenomenon that occurs after the primary zoospore is infected with the root hair.

Until now, avoidance of continuous cropping of susceptible cruciferous vegetables was promoted as one of the most fundamental countermeasures for the control of clubroot disease. However, continuous cropping of suceptible cruciferous vegetables will be a useful technique to decrease resting density specifically under conditions of high soil pH.     

Effect of the amelioration of soil acidity and continuous cropping of cruciferous vegetables on the incidence of clubroot disease and resting spore density in soil

pp. 891–896
In order to elucidate the effect of converter furnace slag applied as a liming amendment and continuous cropping of Qing gin cai ( Brassicae chinensis L.) or leaf daikon ( Raphanus sativus ) on the incidence of clubroot disease and the resting spore density in soil, pot cultivation tests were carried out. In the pot tests, pH(H₂O) was 5.2–6.1 in the non-application pot, and 7.1–7.6 in the pots receiving an application of converter furnace slag.
A significant incidence of club-root disease was apparent in the non-application pots of Qing gin cai . The resting spore density in the soils decreased soon after harvesting, but then increased after mixing the infected roots and soils.
On the other hand, the incidence of the disease was suppressed significantly, in application pots of continuously cropped Qing gin cai . Furthermore, the resting spore density in these soils decreased with repeated cultivation.
These results agreed well with the results from field cultivation tests that the authors have already reported. Macfarlane has reported that the suppression mechanism of clubroot disease brought about by the amelioration of soil acidity is effected through the inhibition of resting spore germination.
In this study, the decrease of resting spores density was associated with the cultivation of Qing gin cai under conditions of high soil pH. From these results, it is concluded that the suppression mechanism is caused by some phenomenon that occurs after the primary zoospore is infected with the root hair.
Until now, avoidance of continuous cropping of susceptible cruciferous vegetables was promoted as one of the most fundamental countermeasures for the control of clubroot disease. However, continuous cropping of suceptible cruciferous vegetables will be a useful technique to decrease resting density specifically under conditions of high soil pH.     

New buffer pH method for rapid estimation of exchangeable acidity and lime requirement of soils

Abstract

A new buffer pH method (BpH) for the rapid estimation of unbuffered salt‐exchangeable acidity (ACe) and lime requirement (LR) has been developed. The buffer reagent, consisting of sodium glycerophosphate, acetic acid, trletlianolamine, ammonium chloride and barium chloride, was useful within the pH range 3.8 to 6.6. Delta values from BpH were converted into buffer pH acidity values (AC) and calibrated against ACe of 91 mineral soils and 100 acid Histosols. The correlation coefficients between AC and ACe were 0.966 and 0.956 for the mineral soils and Histosols, respectively. The corresponding regression equations in terms of meq/100 cm were ACe ‐ ‐0.54 + 0.96 AC and ACe = ‐7.4 + 1.6 AC for mineral soils and Histosols, respectively.

To predict lime requirement of mineral soils a curvilinear equation was required. The equation, LR in meq CaCO₃/100 cm³ = 0.1 (AC)² + AC, was tested successfully against rates of lime carried out under laboratory conditions and against crop response in the greenhouse. Field studies on acid Histosols with maize and soybeans showed optimum yield when the rate of lime added was approximately equivalent to ACe.     

The application of biochar on soil acidity and other physico‐chemical properties of soils in southern Ethiopia

The aim of this research was to investigate the effect of biochar amendment on soil acidity and other physico‐chemical properties of soil in Southern Ethiopia using a field experiment of three treatments: (1) biochar made of corn cobs, (2) biochar made of chopped Lantana camara stem, and (3) biochar made of Eucalyptus globulus feedstock and a control, in which neither of the biochar was used. Each treatment had three levels of 6, 12 and 18 t ha⁻¹. The experiment was setup with RCBD in a factorial arrangement with three replications. In this regard, a total of 36 plots (each 2 × 2 m size) were applied with three replications to the depth of 0–15cm. From these 36 plots, composite soil samples were collected to the depth of 0–30 cm and analyzed for bulk density, total porosity, pH, soil organic carbon, total nitrogen, available phosphorus, potassium, and exchangeable acidity using standard procedures before and after biochar application. Two‐way ANOVA was also used to analyze the impact of the biochars on soil acidity and other properties. For the treatments that had significant effects, a mean separation was made using Least Significance Difference (LSD) test. The results showed the application of biochar significantly reduced, soil bulk density and exchangeable acidity when compared with a control (p < 0.05). Moreover, the total soil porosity, soil pH, total nitrogen, soil organic carbon, available phosphorus, and potassium were significantly increased in the soil. From among applied biochar treatments, Lantana camara applied at the level of 18 t ha⁻¹ had a higher impact in changing soil physico‐chemical properties. In general, the study suggests that the soil acidity can be reduced by applying biochar as it can amend other soil physico‐chemical properties.     

四川茶区土壤营养元素背景值研究

采用单道扫描等离子发射光谱仪(ICP-AES)对四川茶区72个产茶县422个取样点035.cm土层中P、S、K等17种营养元素含量进行测定,分析了该地区茶园土壤的无机营养元素背景值特征。结果表明,四川茶区土壤中P、K、Ca、Mg、S等5种大、中量元素均相对贫乏;微量元素Mn、B、Zn在大部分地区土壤中相对富集,而Fe、Mo在大部分地区土壤相对贫乏;其他元素中Se和Sb相对富集,其浓集系数K值分别为5.45和22.3。方差分析表明,17种营养元素的含量在不同产茶地区土壤中的差异均显著。土壤中营养元素的背景值因土壤类型的不同而表现出一定的差异,其中棕壤中的营养元素含量相对丰富,而红壤中营养元素的含量相对缺乏。因此应有针对性地增施有机肥及微量元素肥料,以补充相对贫乏的营养元素。     

土壤母质与茶叶质量的关系初探

Six tea plantations with different soil-forming parent naterials,the same tea variety and tea age and similar landforms and management were selected to conduct a systematic study on the realtionship between soil properties and tea quality.The results showed that the quality of tea grown on the soil derived from dolomites,Quaternary red clays,were inferior.Further study showed that sandy soils were beneficial to improving amino acid content of tea ,and clayey soils made it decrease;high content of bases might decrease the contents of tea polypenols,caffeine,water extracts,but promote the content of amino acds;available phosphorous was significantly positively correlated with water extracts ,but significantly negatively correlated with caffeine;slowly avaiable potassium was positively correlated with amino acid content .Soil parent materials should be regarded as an important factor in eveluating the adatability of tea to soils.     

添加生物质炭对红壤水稻土有机碳矿化和微生物生物量的影响

通过室内培育试验,研究了添加生物质炭对江西红壤水稻土有机碳矿化和微生物生物量碳、氮含量的影响。结果表明:红壤有机碳矿化速率在培育第2天达最大值后迅速降低,培养7天后下降缓慢并趋于平稳;添加生物质炭降低了土壤有机碳的矿化速率和累积矿化量,培养结束时,不加生物质炭的对照处理中有机碳的累积矿化量分别比添加0.5%和1.0%生物质炭的处理高10.0%和10.8%。此外,生物质炭的加入显著提高了土壤微生物生物量,添加0.5%生物质炭处理的土壤微生物生物量碳、氮含量分别比对照高111.5%～250.6%和11.6%～97.6%,添加1.0%生物质炭处理的土壤微生物生物量碳、氮含量分别比对照高58.9%～243.6%和55.9%～110.4%。相同处理中,干旱的水分条件下(40%田间持水量)微生物生物量要高于湿润的水分条件(70%田间持水量)。同时,添加0.5%和1.0%的生物质炭使土壤代谢熵分别降低2.4%和26.8%,微生物商减少了43.7%和31.7%。     

Effect of application of extracted Oolong tea residue on behavior of nitrate in soil

(Jpn. J. Soil Sci.Plant Nutr., 77, 329–331, 2006)     

玉米秸秆生物炭对褐土微生物功能多样性及 细菌群落的影响

生物炭施入土壤被认为是一种有效的固碳减排措施,可增加土壤有机碳及矿质养分含量,提高土壤的持水能力及保肥能力。为探明其施入土壤后对土壤微生物活性及多样性的影响,本文在盆栽试验条件下,采用Biolog与高通量测序相结合的方法,研究了CK(不施生物炭)和施用5 g·kg~(-1)、10 g·kg~(-1)、30 g·kg~(-1)、60 g·kg~(-1)玉米秸秆生物炭对土壤微生物碳源利用能力(AWCD)、功能多样性指数以及土壤细菌的丰度和多样性的影响。结果表明,随着生物炭施用量的增加,表征土壤微生物活性的AWCD值呈下降趋势,表现为:5 g·kg~(-1)处理≈CK10 g·kg~(-1)处理30 g·kg~(-1)处理60 g·kg~(-1)处理,其中CK和5 g·kg~(-1)处理间差异不显著(P0.05),而10 g·kg~(-1)、30 g·kg~(-1)和60 g·kg~(-1)处理在整个培养期间的AWCD值显著低于CK处理(P0.05);土壤微生物群落代谢功能多样性指数(H′)、碳源利用丰富度指数(S)均随生物炭施用量的增加而呈下降趋势,但均匀度指数(E)表现出相反趋势,5g·kg~(-1)、10 g·kg~(-1)、30 g·kg~(-1)、60 g·kg~(-1)各处理的H′较CK处理分别增加0.16%、-0.88%、-3.14%、-11.09%,S分别增加-2.82%、-11.27%、-18.31%、-47.89%,E分别增加1.14%、3.00%、3.73%和13.76%。主成分分析表明,与CK处理比较,5 g·kg~(-1)处理对土壤微生物群落碳源利用方式没有显著影响(P0.05),而10 g·kg~(-1)、30 g·kg~(-1)和60g·kg~(-1)处理对土壤微生物群落碳源利用方式影响显著(P0.05)。随着生物炭施用量的增加,土壤细菌OTU数目及丰富度指数(Chao1)呈增加趋势,5 g·kg~(-1)处理与CK处理差异不显著,而10 g·kg~(-1)、30 g·kg~(-1)、60 g·kg~(-1)处理的OTU数目较CK处理分别增加1.09%、5.26%、24.42%,Chao1分别增加5.73%、10.21%、37.68%。土壤中施用生物炭后土壤细菌变形菌门(Proteobacteria)的丰度在CK处理和5 g·kg~(-1)处理间差异不显著(P0.05),而10g·kg~(-1)、30 g·kg~(-1)、60 g·kg~(-1)处理较CK处理分别增加32.3%、21.1%、16.7%,拟杆菌门(Bacteroidetes)的丰度随着生物炭施用量的增加各处理较CK处理分别减少22.1%、55.3%、66.8%、50.5%。生物炭施入土壤后降低了土壤可培养微生物的活性,减少或改变了土壤微生物碳源利用的种类,使土壤原有微生物群落组分发生改变,生物炭也影响了土壤细菌各菌群在土壤中的丰度,使其分布的均匀性降低。为了不影响微生物群落结构和功能,石灰性褐土上生物炭一次还田量不能超过5 g·kg~(-1)(干土)。     

施用碱稳定固体减轻酸性土壤的酸度和铝毒

A pot experiment was catried out to study alleviation of soil acidity and Al toxicity by applying analkaline-stabilised sewage sludge product (biosolids) to an acid clay sandy loam (pH 5.7) and a strongly acidsandy loam (pH 4.5). Barley (Hondeum vulgare L. cv. Forrester) was used as a test crop and was grownin the sewage sludge-amended (33.5 t sludge DM ha^-1) and unamended soils. The results showed that thealka1ine biosloids increased soil pH from 5.7 to 6.9 for the clay sandy loam and from 4.5 to 6.0 for the sandyloam. The sludge product decreased KCl-extractable Al from 0.1 to 0.0 cmol kg^-1 for the former soil and from 4.0 to 0.1 cmol kg^-1 for the latter soil. As a result, barley plants grew much better and grain yield increased greatly in the amended treatments compared with the unamended controls. These observations indicate that alkaline-stabilised biosolids can be used as a liming material for remedying Al phytotoxicity instrongly acid soils by increasing soil pH and lowering Al bioavailability.     

贵州茶区土壤养分状况综合评价

应用SPSS统计软件,对贵州全省70个茶园土壤样品8项养分指标进行主成分分析,按累计贡献率达到85%以上提取了4个主成分,并求出各土壤养分的4个主成分综合得分。并对综合得分以欧氏距离为衡量土样间差异大小的指标,采用类平均法进行聚类分析。将70个土样分为Ⅰ、Ⅱ、Ⅲ、Ⅳ等级,第Ⅰ类为养分丰富型土壤,其各项养分指标最高,综合得分范围0.63≤F≤1.08,所占比例9.83%;第Ⅱ类为养分较丰富型土壤,其综合得分范围0.10≤F≤0.53,所占比例29.51%,相对Ⅰ类,有机质和全磷含量相对不足;第Ⅲ类茶园土壤肥力一般,其综合得分范围-0.32≤F≤0.02,所占比例36.07%;第Ⅳ类土壤各养分因子均缺乏,为养分缺乏型茶园土壤。