Combined Chemical and Mineralogical Evidence for Heavy Metal Binding in Mining- and Smelting-Affected Alluvial Soils

The binding of metallic contaminants （Pb, Cd, and Zn） and As on soil constituents was studied on four highly contaxninated alluvial soil profiles from the mining/smelting district of Pribram （Czech Republic） using a combination of mineralogical and chemical methods. Sequential extraction analysis （SEA） was supplemented by mineralogical investigation of both bulk samples and heavy mineral fractions using X-ray diffraction analysis （XRD） and scanning electron microscopy with an energy dispersive X-ray spectrometer （SEM/EDS）. The mineralogy of Fe and Mn oxides was studied by voltammetry of microparticles （VMP） and diffuse reflectance spectrometry （DRS）. Zinc and Pb were predominantly bound in the reducible fraction attributed to Fe oxides and Mn oxides （mainly birnessite, Na4Mn14O27.9H2O）, which were detected in soils by XRD and SEM/EDS. In contrast, Cd was the most mobile contaminant and was predominantly present in the exchangeable fraction. Arsenic was bound to the residual and reducible fractions （corresponding to Fe oxides or to unidentified Fe-Pb arsenates）. SEM/EDS observations indicate the predominant affinity of Pb for Mn oxides, and to a lesser extent, for Fe oxides. Thus, a more suitable SEA procedure should be used for these mining-affected soils to distinguish between the contaminant fraction bound to Mn oxides and Fe oxides.

Effects of land uses on soil physic-chemical properties and erodibility in collapsing-gully alluvial fan of Anxi County,China

the National Key Technologies R＆D Program of China during the 12th Five-Year Plan period （2011BAD31B00）

Free Oxide Distribution in Poorly and Well Drained Soils Developed on Calcareous Alluvial Deposits

A study on the distribution of free iron and manganese oxides was conducted in soils developed on calcareous alluvial deposits under subhumid climatic conditions, in Western Greece. Soil samples from two well drained soils and from two poorly drained soils, classified as Alfisols, were collected and used in this study. After certification of soil homogeneity the acid ammonium oxalate and dithionite-citrate-bicarbonate methods were used to extract free iron and manganese oxides from the samples. Iron oxides extracted by the dithionite-citrate-bicarbonate method (Fed) were significantly higher than the iron oxides extracted by the ammonium oxalate method (Feo), indicating that a considerable fraction is present in crystalline forms,independent of drainage status. A confirmation of free iron oxides and fine clay was detected. The ratios Feo/Fed and (Fed-Feo)/total Fe (Fet) could not be used to distinguish the well drained soils from the poorly drained soils. Manganese movement in a soluble form is independent of the fine clay.

Sufficiency and Deficiency Indices of Soil Available Zinc for Rice in the Alluvial Soil of the Coastal Yellow Sea

To determine the sufficiency and deficiency indices of soil available Zn by the Agro Services International （ASI） method （ASI-Zn） for Zn fertilizer recommendation in rice production in the alluvial soil of the coastal Yellow Sea, the relationship between relative rice yield and soil available ASI-Zn concentration was analyzed from a ten-field experiment with various soil test classes ranging from low to high fertility in 2005 and 2006, and nine Zn fertilizer application rates （0, 7.5 15, 22.5, 30, 37.5, 45, 52.5 and 60 kg Zn/ha） arranged at random with three replications in each field. There was a significant quadratic relationship between soil available ASI-Zn and rice yield, and a significant linear relationship between soil available ASI-Zn concentration and Zn fertilization rate. For rice variety Wuyujing 3, soil available ASI-Zn was deficient when the value was at lower than 1 mg Zn/L, low at 1 to 2 mg Zn/L, sufficient at 1 to 2 mg Zn/L, excessive at higher than 7.5 mg Zn/L. Thus, Zn fertilizer recommendation could be done according to the sufficiency and deficiency indices of soil ASI-Zn. For most of alluvial soils of the coastal Yellow Sea in the study, the available ASI-Zn was lower than 1 mg Zn/L, and then the optimum application rate of Zn fertilizer was about 20 kg Zn/ha.

Soil evolution along an alluvial-loess transect in the Herat Plain,western Afghanistan

Afghanistan is located in the Eurasian loess belt,however,there is little information on the soils in the area.Loess has covered the Herat Plain in western Herat City,Afghanistan.Despite the diversity of landform and parent material,there is no information on the soil and landform evolution in this area.The objectives of this study were to identify the soils along a transect of different landforms in the Herat Plain and determine the role of geomorphic processes on the soil and landform evolution.Five pedons from an alluvial fan,the depression between alluvial fan and piedmont plain,saline and non-saline piedmont plains,and the flood plain of the Hariroud River,were sampled.Then,the physical-chemical properties,mineralogy,and micromorphology of the samples were determined.Results showed that the soil parent material in the piedmont plain is loess,whereas,in the flood plain it is a combination of loess and river alluvial sediments.Calcification,lessivage,salinization,and gleization are the most important pedogenic processes.The calcification and lessivage appear to be the result of a wetter climate during the late Quaternary,whereas the present topography causes the gleization and salinization.Clay coatings on carbonate nodules and iron nodules are abundant pedofeatures in the Btk(argillic-calcic)horizon.Iron oxides nodules are common in the soils of the flood plain.The formation of palygorskite in both alluvial-and loess-derived soils implies the onset of aridity and the trend of increase in environmental aridity in the region.It seems that after the formation of a well developed paleosol on the alluvial fan in a more humid climate in the past,the piedmont plain has been covered by loess deposits,and the calcification,gleization,and salinization cause the formation of weakly developed surficial soils.This study highlights the role of the late Quaternary climatic changes on the evolution of landforms and soils in western Afghanistan.

Effects of Soil Management on Changes of Soil Carbon Content in Alluvial Paddy Soil

Effects of soil management on carbon content in alluvial paddy were investigated using past soil survey data of Niigata prefecture, Japan. The changes of soil management were as follows： （1） slight decrease in nitrogen and phosphate fertilizer application rates; （2） decrease to half in the application of soil amendments, like calcium silicate; （3） decrease in compost application and increase in rice straw application; （4） increase in pipe drainage. In spite of these changes, negligible change of carbon content in the plow-layer of alluvial paddy soils had been observed for past 25 years. However, without rice straw application and paddy-upland rotations, the soil carbon content had been decreased. Carbon content of alluvial paddy soils classified into Gley Lowland soil （Fluvisol or Gleysol） at the depth of 0-30 cm was calculated about 49-103 g-kg＂1 and gross carbon sequestration was calculated 7.68 Mt in the paddy field soils in Niigata prefecture.

硝化抑制剂对湖南紫潮泥田紫云英-稻秸还田后水稻产量及镉吸收的影响

研究紫云英-水稻制度下,稻秸还田和硝化抑制剂对水稻生长和镉(Cd)吸收的影响,为湖南双季稻田基于绿肥的稻米安全生产措施提供理论支撑。池栽微区试验设4个处理:紫云英(GM)、紫云英+化肥(GF)、紫云英+稻秸+化肥(GRF)、紫云英+稻秸+化肥+硝化抑制剂(GRFD)。分析了不同措施下的水稻产量与养分积累、稻米Cd吸收、土壤肥力及土壤Cd有效性和形态。相比GRF处理,GRFD处理早稻籽粒和稻秸产量分别增加7.0%和12.2%。GRFD处理下,早稻籽粒氮、磷、钾养分累积量较GRF处理分别增加5.5%、10.1%、6.8%。GF、GRF、GRFD处理早稻籽粒Cd含量较GM处理分别降低64.8%、67.3%、66.8%。GRFD处理早稻可溶性有机碳和可溶性有机氮含量,相比GRF处理分别降低41.2%和8.0%。GRFD处理早稻和晚稻土壤有效态Cd含量,相比GRF处理分别降低70.9%和66.0%,相比GF处理分别降低80.2%和61.4%;GRFD处理晚稻土壤可氧化态Cd含量相比GRF处理增加了52.6%,表明紫云英-稻秸-硝化抑制剂联合利用通过将土壤Cd转变为难以被水稻吸收的形态而降低其有效性。随机森林与相关性表明,早、晚稻速效钾与有效磷在限制水稻吸收Cd中均起到了关键作用。在紫云英-稻秸联合还田条件下,配施硝化抑制剂可提高水稻产量、促进水稻养分吸收,同时通过增加土壤速效钾和有效磷含量,进而减少水稻对Cd的吸收。

冀北花岗岩地区坡积冲洪积型污染耕地土壤治理比较研究

土壤是农业生态系统重要的组成部分,耕地土壤重金属污染会影响农产品质量安全。本研究选取冀北花岗岩地区坡积物母质区和冲洪积物母质区的弱酸性农田土壤为研究对象,依托钝化修复和植物提取(玉米和龙葵为植物修复材料)两种修复技术,探究了不同成土母质类型和修复技术对耕地土壤重金属的修复效果影响。研究结果表明:(1)坡积物和冲洪积物母质区土壤的有机质、速效钾、有效磷和pH值存在显著差异,坡积物母质区土壤pH显著低于冲洪积物母质区土壤,两区成土母质均具有较高的Pb背景值;(2)钝化修复后,冲洪积物母质区玉米籽粒Cd和Pb含量显著降低,玉米籽粒增产19.10%~33.00%,较坡积物母质区显示出更好的修复效果;(3)坡积物母质区采用龙葵和玉米间作模式,植物修复每年每公顷中提取Cd、Pb和Cu分别为167.25、208.35和555.05 g,Cd、Pb和Cu的去除率分别为2.727%、0.043%和0.234%,较冲洪积物母质区显示出更好的修复效果;(4)龙葵和玉米的间作模式优于单一种植模式,间作可以提高土壤中重金属的生物可利用性和植物吸收效率;(5)制定土壤污染修复策略时,需考虑土壤特性、成土母质及不同农作物的影响,选用合适的修复技术和种植模式。本研究可为地质异常区域农田土壤安全利用与修复提供参考依据。

不同砷水平下小麦砷迁移累积特征及健康风险评价

通过研究土壤在不同浓度As污染条件下的小麦生长发育及As迁移富集特征,以评估不同As浓度胁迫下小麦籽粒的健康风险,进而提出适宜甘肃省小麦生产实际的土壤As污染临界值。以灌淤土为研究对象,以春小麦品种宁春4号为指示作物,参照《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618—2018)中土壤As风险筛选值,按照土壤质量标准0~3倍As含量设置7个浓度梯度,进行了土壤-小麦系统As毒性盆栽试验。结果显示,不同浓度As胁迫下,小麦根系、茎叶、籽粒中As含量均随土壤As浓度的增加而增加,小麦植株不同部位的As含量由高到低的顺序为根系、茎叶、籽粒。小麦不同部位对As的富集能力表现为:根系>茎叶>籽粒,且根系、茎叶As富集能力随着土壤中As浓度的增加大体呈先增加后减小的趋势。As在小麦植株中转运系数表现为TF茎叶/根>TF籽粒/茎叶>TF籽粒/根,以根系向茎叶迁移过程为主。以甘肃省成人为评价对象,利用人体健康风险评价模型,采用靶标危害系数法(THQ)得出,除对照不添加As2O5处理外,其余As胁迫各处理的小麦籽粒人体健康风险系数均超出USEPA推荐的最大可接受风险临界值(即THQ>1.00),且随土壤As含量增加呈先升高后降低的趋势。根据甘肃省当地居民饮食习惯,结合人体健康风险评价模型,认为甘肃省小麦安全生产土壤推荐As浓度应低于29.200 mg/kg。

基于时间序列的长江下游冲积平原区农田土壤质量演变特征

为揭示人类活动影响下土壤质量的演变趋势及其影响因素,在长江下游沿江平原典型区建立了0、60、160、280、2000和3000 a的土壤围垦时间序列,分析不同围垦时间与土地利用下土壤理化性质的差异。调查结果表明,围垦后表层土壤中的碳酸盐快速丧失,土壤逐渐由弱碱性转为弱酸性,围垦3000 a后旱地土壤pH值约降低了2。长期水旱轮作的利用方式下,由于稻季土壤复盐基作用和氧化还原交替的状态,酸化程度略低。围垦之后相当长的一段时间内有机碳(SOC)、全氮(TN)和凯氏氮(AN)含量均呈逐渐积累的趋势,在表层土壤无机碳逐渐降低的同时,SOC含量比围垦前总体有所提高,表明耕作培肥措施在一定程度上有利于SOC和养分的积累。但围垦历史最久的圩区其SOC、TN和AN含量又有不同程度的降低,全磷(TP)和有效磷(AP)含量除在围垦初期有所升高,后期则不断降低。水旱轮作的利用方式下,土壤磷素的耗竭问题尤其突出,显示区内农田养分的投入处于不同程度的亏缺状态。目前的管理方式下,土壤肥力质量退化的现象应当引起足够的重视。

黄河下游冲积平原土壤水带土体质地空间变异特征研究

选择河南省开封市兰考县中部闫楼乡作为研究区,运用经典统计学、地统计学与Voxler相结合的方法,研究土壤水带土体质地的空间变异性和分布规律。结果表明:研究区土壤水带不同土体颗粒的空间变异性具有显著差异,变异性强度为砂粒>黏粒>粉粒,且土体质地的空间变异性强度随土壤水带深度增加而增大。土壤水带砂、粉、黏粒的空间相关程度不同,空间相关性强度黏粒>砂粒>粉粒。土壤水带中,砂粒在浅层的空间分布最优模型为高斯模型,在中层和深层为球状模型;粉粒在浅层和中层的空间分布最优模型均为高斯模型;黏粒的空间分布最优模型在浅层和深层的为球状模型,中层为高斯模型。

黄河下游冲积平原试验区土壤水分特征曲线的传递函数研究

黄河下游冲积平原区是我国重要的粮食生产基地和工业集聚地,该地区土壤水力学参数的获取,对于保障用水安全和指导农业生产具有重要意义。为建立黄河下游冲积平原区的土壤水分特征曲线传递函数(PTFs),以河南省兰考县闫楼乡作为黄河下游冲积平原试验区,基于多元非线性逐步回归和单因素扰动方法,建立了包气带土壤水分特征曲线的PTFs,并分析了影响因素敏感性。研究结果显示,实测土壤水分特征曲线以及土壤理化性质参数呈现较强变异性,所建立的PTFs精度良好,具备应用推广价值。多元回归结果表明,土壤颗粒组成是本文PTFs的主要影响因素,其中黏粒含量对PTFs最为敏感,砂粒含量次之,粉粒含量最弱。在其余5个土壤理化特性中,对PTFs的相对敏感的因素是pH值和分形维数。研究表明,土壤物理化学性质与土壤水分特征曲线模型参数的关系复杂,并非一般线性或单调关系。尽管土壤物理化学性质参数可以提高PTFs精度,但土壤颗粒组成是影响土壤水分运动的根本原因,其作为构建PTFs的关键因素不可忽略。在实际应用中,PTFs使用者可根据所掌握数据的实际情况,结合影响因素敏感性,决定影响因素的取舍。

Microbe—Chloroacetanilide Herbicide Interaction across Soil Type

An investigation was carried out under laboratory conditions to study the persistence of butachlor applied at recommended dose (2 kg ai/ha) along with its impact on microbial activity as well as growth of colonial bacteria and fungi in alluvial (Typic Haplaquent), lateritic (Typic Haplustalf) and coastal (Typic Haplaquept) soils. Butachlor caused a significant increment in microbial activity following an initial diminution in between 10 to 22 days of incubation depending on the type of soil. The herbicide resulted in a significant shrinkage in bacterial community during later stages of incubation in lateritic and coastal soils in spite of a significant swelling on the 15th day in lateritic and alluvial soils. Fungal community significantly expanded at the initial stage in lateritic soil and during later stages in alluvial soil by the application of butachlor but shriveled during later stages in the lateritic soil, intermediate stage in coastal soil and initial stages in alluvial soil. Alluvial soil reared the highest population of colonial bacteria and exhibited highest microbial activity while coastal soil significantly pressed them down to the lowest. However, lateritic soil was the best niche for fungal community. Co-metabolism was the main phenomenon in butachlor metabolism particularly in coastal soil, though zymogenous microbes including bacteria and fungi also participated in both lateritic and alluvial soil at certain stages. The persistence of butachlor was the lowest in alluvial soil followed by lateritic and coastal soil, respectively. Among the soil types application of butachlor is safe in alluvial soil.

贺兰山东麓冲积扇区不同微地形土壤理化性质及酶活性特征

【目的】以贺兰山东麓冲积扇为研究对象,分析不同微地形土壤理化性质与土壤酶活性的空间分布特征及其差异性,探讨两者间相互关系,为贺兰山东麓冲积扇发育机制研究、生态修复及农业生产等提供理论基础。【方法】以野外调查取样和实验室分析测定为基础,运用经典统计学方法对不同微地形(冲积台地、高漫滩、槽滩、沟床)和不同土层深度(0~20、20~40 cm)的土壤理化性质与土壤酶活性进行分析,同时利用地理探测器结合典范排序方法对土壤酶活性与土壤理化性质的关系进行研究。【结果】在不同微地形,土壤砾石含量、有机质、全氮和碱解氮含量表现为冲积台地>高漫滩>槽滩>沟床,速效磷和速效钾含量表现为高漫滩>冲积台地>槽滩>沟床,各元素含量随着土层厚度增大而降低;土壤pH、全磷和全钾含量在不同微地形差异不显著;土壤酶活性在不同微地形表现为碱性磷酸酶与脲酶活性为冲积台地最高,沟床最低,过氧化氢酶与过氧化物酶活性为沟床最高,冲积台地最低。碱性磷酸酶、脲酶和过氧化氢酶活性随着土层厚度增加而减少,过氧化物酶活性随着土层厚度的增加而增加。地理探测器探测结果显示:研究区不同微地形土壤酶活性空间分异是各土壤理化性质共同作用的结果,不同因子对土壤酶活性的影响程度不尽相同。通过进一步的冗余分析表明:全氮、碱解氮、土壤砾石含量和速效钾是影响贺兰山东麓冲积扇区土壤酶活性变化的主要指标,重要性大小排序为:全氮>碱解氮>土壤砾石含量>速效钾。【结论】贺兰山东麓冲积扇区不同微地形土壤理化性质与土壤酶活性分布存在显著差异,土壤各理化性质对土壤酶活性的作用强弱不尽相同,揭示了土壤理化性质与土壤酶活性关系的复杂性及酶活性空间分布变异影响因子的多样性。

Mining Threats to Ancient Anthropogenic Soils and other Resources Associated to Indigenous Food Security in the Middle Caqueta River, Colombia

Mining is encroaching upon Protected Areas and Indigenous Reserves in the Colombian Amazon. In the Middle Caqueta region small-scale, illegal gold mining is eroding riverbanks, affecting water quality, and jeopardizing the livelihoods of indigenous peoples. In addition, mining also threatens the integrity of pre-Columbian anthropogenic soils （terra preta） created between 500 years to 2,000 years B.P. on the bluffs of the Caqueta . River. These soils are the only, non-flooded fertile soils present in the region, and as such are important for local indigenous communities. In Colombia, there is little knowledge about Terra Preta soils. This work assesses the present and potential dangers artisanal mining has for terra preta soils and other natural resources that are central to indigenous peoples＇ food security. Results posit that more knowledge is needed about the way terra preta soils are related to the livelihoods of indigenous people so that informed policy decisions can be made about the desirability of mining in the region.

冬种紫云英对石灰性水稻土紫潮泥锌形态的影响

为了解种植紫云英对洞庭湖西北部石灰性水稻土中锌形态转化的驱动作用及其机理,以南县地区湖积物发育出来的紫潮泥为研究对象,通过盆栽试验研究了冬种紫云英和冬闲处理对紫潮泥锌形态及其相互间关系的影响,探讨冬种紫云英后不同形态锌在紫潮泥中的含量变化。结果表明:2个处理均提高了土壤pH值和交换态锌含量,冬种紫云英处理的增幅略低;2个处理均提高了土壤紧结有机结合态锌含量,冬种紫云英处理的增幅更高;冬闲处理提高了氧化锰结合态锌含量,而冬种紫云英处理降低了氧化锰结合态锌含量;2个处理均降低了土壤松结有机结合态锌、碳酸盐结合态锌和矿物残渣态锌含量,冬种紫云英处理对土壤松结有机结合态锌含量的降幅更大,而对碳酸盐结合态锌和矿物残渣态锌含量的降幅较小;冬种紫云英在整个生长期内并不能明显增加紫潮泥的DTPAZn含量;土壤中的锌主要以残渣态存在,其他形态锌占全锌的比例均很小,不足1%。

黄河冲积粉土地区深基坑变形三维有限元分析

依托黄河流域冲积粉土地区深基坑工程,采用大型岩土工程有限元软件PLAXIS 3D建立了深基坑三维有限元模型,土体采用硬化土本构模型,分析了基坑开挖对围护结构及周边环境变形的影响,研究了围护桩嵌固深度及地下水位对基坑围护结构变形的影响。结果表明:采用硬化土本构模型能较好地预测黄河流域冲积粉土围护结构的变形和周边沉降;随围护桩嵌固深度增大,基坑围护结构水平位移减小,但减小的幅度也越来越小;考虑降水的基坑围护结构水平位移远小于不考虑降水情况,应做好降水措施,防止围护结构变形过大。

Carbon mineralization in subtropical alluvial arable soils amended with sugarcane bagasse and rice husk biochars

Subtropical recent alluvial soils are low in organic carbon(C).Thus,increasing organic C is a major challenge to sustain soil fertility.Biochar amendment could be an option as biochar is a C-rich pyrolyzed material,which is slowly decomposed in soil.We investigated C mineralization(CO_(2)-C evolution)in two types of soils(recent and old alluvial soils)amended with two feedstocks(sugarcane bagasse and rice husk)(1%,weight/weight),as well as their biochars and aged biochars under a controlled environment(25±2℃)over 85 d.For the recent alluvial soil(charland soil),the highest absolute cumulative CO_(2)-C evolution was observed in the sugarcane bagasse treatment(1140 mg CO_(2)-C kg^(-1)soil)followed by the rice husk treatment(1090 mg CO_(2)-C kg^(-1)soil);the lowest amount(150 mg CO_(2)-C kg^(-1)soil)was observed in the aged rice husk biochar treatment.Similarly,for the old alluvial soil(farmland soil),the highest absolute cumulative CO_(2)-C evolution(1290 mg CO_(2)-C kg^(-1)soil)was observed in the sugarcane bagasse treatment and then in the rice husk treatment(1270 mg CO_(2)-C kg^(-1)soil);the lowest amount(200 mg CO_(2)-C kg^(-1)soil)was in the aged rice husk biochar treatment.Aged sugarcane bagasse and rice husk biochar treatments reduced absolute cumulative CO_(2)-C evolution by 10%and 36%,respectively,compared with unamended recent alluvial soil,and by 10%and 18%,respectively,compared with unamended old alluvial soil.Both absolute and normalized C mineralization were similar between the sugarcane bagasse and rice husk treatments,between the biochar treatments,and between the aged biochar treatments.In both soils,the feedstock treatments resulted in the highest cumulative CO_(2)-C evolution,followed by the biochar treatments and then the aged biochar treatments.The absolute and normalized CO_(2)-C evolution and the mineralization rate constant of the stable C pool(K_(s))were lower in the recent alluvial soil compared with those in the old alluvial soil.The biochars and aged biochars had a negative priming effect in both soils,but the effect was more prominent in the recent alluvial soil.These results would have good implications for improving organic matter content in organic C-poor alluvial soils.

Weathering reflected by the chemical composition of alluvial soils from the Zeya and Selemdzha river valleys

The paper examines the chemical composition of alluvial soils from the Zeya and Selemdzha River valleys, one of the branch rivers in the Amur River basin. It has been established that the compositions of these soils are characterized by a relative shortage of practically all analyzed macro-and microelements as compared with UCC(upper continental crust) and PAAS(postArhean Australian average shale) compositions. The chemical composition of alluvial soils approximates that of the soils in NE China and Korea due to similar climatic and geographic conditions. On the basis of relationships between major and trace elements and peculiarities of trace elements concentration it is shown that the alluvial soils in the middle reaches of the Zeya River were formed by the sources largely transformed by chemical weathering processes. By comparison, the soils in the Selemdzha River and lower reaches of the Zeya River(below the Selemdzha River mouth) are dominated by material to a large degree reworked by the physical processes rather than chemical ones. This inference conforms with specific geological settings of the water-collector.

生物炭对不同土壤化学性质、小麦和糜子产量的影响

以小麦和糜子为供试作物,利用室外盆栽试验,研究了不同添加量生物炭与矿质肥配施对两种不同土壤化学性质及小麦和糜子产量的影响。生物炭当季用量设5个水平:B0(0 t/hm2)、B5(5 t/hm2)、B10(10 t/hm2)、B15(15 t/hm2)和B20(20 t/hm2),氮磷钾肥均作基肥施用。结果表明:1)与对照相比,施用生物炭可以显著增加新积土糜子季土壤pH值,其他处理随生物炭用量的增加虽有增加趋势但差异不显著;显著增加新积土土壤阳离子交换量,增幅为1.5%—58.2%;显著增加两种土壤有机碳含量,增幅为31.1%—272.2%;2)两种土壤的矿质态氮含量、新积土土壤有效磷和速效钾含量随生物炭用量的增加而显著提高,氮磷钾增幅分别为6.0%—112.8%、3.8%—38.5%和6.1%—47.2%;3)生物炭可显著提高塿土上作物氮吸收量,而作物磷、钾吸收量虽有增加,但差异不显著。生物炭对小麦和糜子的增产效应尚不稳定,在试验最高用量时甚至产生轻微抑制作用。总之,施用生物炭在一定程度上可以改善土壤化学性质,提高土壤有效养分含量,但生物炭对土壤和作物的影响与土壤、作物类型及土壤肥力密切相关。