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Recent research results suggest that acidification of acid sulfate soils may be inhibited in well-drained estuarine floodplains in eastern Australia by the absence of natural creek levees,The lack of natural levees has allowed the inuudation of the land by regular tidal flooding prior to the construction of flood mitigation work.Such physiographical conditions prevent the development of pre-draingae pyrite-derived soil acidifica-tion that possibly occurred at many levee-protected sites in eastern Australian estuarine floodplains during extremely dry spells.Pre-drainage acidification is considered as an important condition for accumulation of soluble Fe and consequently,the creation of favourable environments for catalysed pyrite oxidation.Under current intensively drained onditions,the acid materials produced by ongoing pyrite oxidation can be rapidly removed from soil pore water by lateral leaching and acid buffering,resulting in low concentrations of soluble Fe in the pyritic layer,which could reduce the rate of pyrite oxidation. 相似文献
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综述: 酸性硫酸盐土壤的环境风险评价分析方法 总被引:1,自引:0,他引:1
Assessment of acid sulfate soil risk is an important step for acid sulfate soil management and its reliability depens very much on the suitability and ccuracy of various analytical methods for estimating sulfide-derived potential acidity,actual acidity and-neutralizing capacity in acid sulfate soils.This paper cirtically reviews various nalytical methods that are currently used for determination of the above parameters,as well as their implications for environmental risk assessment of acid sulfate soils. 相似文献
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1998~2001年在已垦和未垦酸性硫酸盐土壤上连续进行6季作物的磷矿粉肥效试验,4种磷矿粉分别为摩洛哥CALCINE和BRUT,ALGERIA及昆阳磷矿粉,另外加上过磷酸钙和重过磷酸钙及对照。2000年起每小区均分成2个裂区,其中裂区Ⅰ继续按以前磷肥用量施肥,裂区Ⅱ则将后4季作物的肥料1次施下。试验结果表明,在未垦地上,施用磷矿粉处理水稻稻草P含量比对照显著提高,植株吸收N、P、K量、土壤含P量显著增加。磷矿粉为水稻生长提供了稳定有效的P源;水稻根部吸收P并主要储存于稻草中;2种施用方法无显著差异。已垦地上各处理间无显著差异。虽然缺P是制约水稻生长的一个关键因素,但在此类土壤上还存在更多的限制因子。 相似文献
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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. 相似文献
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有机酸对酸性土壤中铝的溶出和铝离子形态分布的影响 总被引:18,自引:6,他引:12
五种低分子量的有机酸对酸性土壤中铝的溶出和铝离子形态分布的影响的研究结果表明,有机酸主要通过与铝形成络合物而促进铝的溶解,使土壤溶液中有机络合态铝浓度增加,有机酸对无机铝形态的影响较小。不同有机酸由于本身的性质和结构不同,它们对铝溶解的影响不同。 相似文献
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某极度酸化的酸性硫酸盐土壤中可溶性和交换性酸的特征 总被引:4,自引:0,他引:4
An extremely acidified acid sulfate soil(ASS) was investigated to characterise its soluble and exchangeable acidity,The results showed that soluble acidity of a sample dtermined by titration with a KOH soulution was much significantly greater than that indicated by pH measured using a pH meter,paricularly for the extremely acidic soil samples,This is because the total soluble acidity of the extremely acidic soil samples was mainly composed of various soluble Al and Fe species,possibly in forms of Al sulfate complexes(e.g.,AlSO4^ ) and feerous Fe(Fe^2 )_,It is therefore suggested not to use pH alone as an indicator of soluble acidity in ASS,particularly for extremely acidic ASS,It is also likely that AlSO4^ actively participated in cation exchange reactions.It appears that the possible involvement of this Al sulfate cation in the cation adsorption has significant effect on increasing the amount of acidity being adsorbed by the soils. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(9):873-882
Abstract A refined scheme for the semi micro chemical analysis of sulfur fractions in soils is presented. Pyrite is analyzed, as iron, after extraction in HNO3. Non‐pyrite iron is excluded by a pretreatment with HF/H2SO4. Water‐soluble sulfate and jarosite [KFe3(SO4)2(OH)6], the other dominant sulfur fractions in acid sulfate soils, are analyzed turbidimetrically, as sulfate, after successive extractions by EDTA.3Na (water soluble plus exchangeable SO4) and by hot 4 M HCl (jarosite). These methods are simpler, less bulky and more specific than most existing procedures. Introduction of elemental sulfur analysis permits estimation of organic sulfur fraction as well. Sums of individual sulfur fractions agree well with separate total sulfur determinations. The proposed analysis of pyrite permits also distinction of the components Fe2O3, FeO and FeS2 in soils and rocks2. 相似文献
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Tanabhatsakorn SUKITPRAPANON Anchalee SUDDHIPRAKARN Irb KHEORUENROMNE Somchai ANUSONTPORNPERM Robert J. GILKES 《土壤圈》2020,30(3):390-404
Potential acid sulfate soils(PASS) are drained for agriculture, resulting in the formation of active acid sulfate soils(AASS), which gradually evolve into post-active acid sulfate soils(PAASS). Various redox concentrations(precipitates, costings, and mottles) occur in these soils as a result of pedogenic processes including biological activity and effects of land management. Although several studies have determined the mineralogy and geochemistry of ASS,the mineralogy and geochemistry of redox concentrations occurring in a sequence of ASS through PASS to PAASS have not been investigated. This study examined the mineralogy and geochemistry of redox concentrations and matrices within 5 PASS, 8 AASS, and 5 PAASS in Thailand. The labile minerals were predominantly controlled by oxidation status and management inputs. The unoxidized layers of PASS, AASS, and PAASS contained pyrite and mackinawite.The oxidation of Fe sulfides caused acidification and accumulation of yellow redox concentrations of jarosite and Fe(hydr)oxides at shallow depths. As the soils became well developed, they were recognized as PAASS, and the jarosite and goethite transformed to hematite. As ASS were drained, Co, Mn, Ni, and Zn moved downward and were associated with Fe sulfides and Mn oxides in the unoxided layer. Concentrations of As, Cu, Cr, Fe, and V did not change with depth because these elements became associated with jarosite and Fe(hydr)oxides in yellow and red redox concentrations, as well as the root zone, in the partly oxidized layer of AASS and PAASS. Arsenic was associated with pyrite under reducing conditions. 相似文献
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酸性硫酸盐土壤会对华南沿海地区河口生态系统造成一种潜在的环境威胁吗? 总被引:2,自引:0,他引:2
Integration of soil information system (SIS) and interactive self-organizing data(ISODATA) was studied to establish proper agricultural developing zones in red soil region of southern China which are of crucial importance to farmers,researchers,and decision maders while utilizing and managing red soil resources.SIS created by using ARC/INFO was used to provide data acquisition,systematic model parameter assignment,and visual display of analytic results.Topography,temperature,soil component(e.g.,organic matter and pH) and condition of agricultural production were selected as parameters of ISODATA model.Taking Longyou County,Zhejiang Province as the case study area,the effect of the integration and recommendations are discussed for future research. 相似文献
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The distribution of iron monosulifde (quantified as acid volatile sulfur:SAV) was compared with geochemical properties that are known to affect its formation and accumulation in three coastal Holocene acid sulfate soils (ASS) at Tuckean Swamp,Mc Leods Creek and Bungawalbyn Swamp respectively,These properties included pH,reactive iron(FeR),pore-water sulfate(SO4^2-) and organic carbon(OC).Iron monosulfide was concentrated at the oxic/anoxic boundary,the Tuckean Swamp and McLeods Creek sites are Holocene sediments,whereas the Bungawalbyn Swamp is a Holocene peat.The concentration of SAV averaged 0.2 g kg^-1 in a 0.5m thick soil layer at the Tuckean Swamp,but was an order of magnitude lower in the oxic/anoxic transition layers at McLeods Creek and Bungawalbyn Swamp,The SAV mineral greigite(Fe3S4) was identified in the Tuckean Swamp by X-ray diffraction and scanning electron microscopy with quantitative energy dispersive X-ray analysis(SEM-EDX),Very small concentrations of greigite were also observed in the McLeods Creek,based on crystal morphology and elemental composition.The concentration of SAV was a small fraction of the total reduced sulfur,representing at most 3% of the pyrite sulfur,However,the presence of this highly reactive sulfide mineral,distributed within pores where oxygen diffusion is most rapid,has important implications to the potential rate of acid production from these sediments. 相似文献
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L.A. Manrique 《Journal of plant nutrition》2013,36(6):677-698
A field experiment using local cassava cultivars was conducted on a Tropudult of Ocu, Panama to study leaf area development and growth performance of cassava germplasm under extreme soil acidity conditions. Plants were grown under a soil Al (KCl‐extractable Al) range of 4.0 to 5.7 cmol(p+)/kg. Under this high soil Al, leaf area index and dry matter production patterns of cassava cultivars were closely similar to those reported for plants grown in less constraining conditions. However, the sink capacity in most cultivars appeared to shift from roots to tops. Roots were weak competitors for assimilates, hence photosynthetic production was primarily aimed to develop and sustain canopy growth. This preferential distribution of assimilates to tops resulted in low harvest index values. The reduced sink size of roots appears to be attributable to the impairing effects of soil Al on root growth. 相似文献
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Acid sulfate voile (ASS), widely distributed in Australia. This has only been recognised recently when intensive rmearch on ASS has been done in this country. This paper reviews aspects concerning a) the distribution and acid potential, b) controls on acidic status, and c) problems and management of ASS in Australia. It is believed that the Australian experience may be useful for other countries where potential problems from ASS exist but insufficient attention was paid to them. 相似文献
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碱性材料对修复与改良酸性硫酸盐土壤障碍因子的研究 总被引:2,自引:0,他引:2
采用盆栽试验研究了不同碱性材料(石灰、自研改良剂、钙镁磷肥)对酸性硫酸盐土壤主要障碍因子的修复及其对水稻生长的影响。结果表明,不同碱性材料对土壤理化特性、土壤养分有效性和水稻生长的影响存在明显差异。与常规施肥(NPK)处理相比,自研改良剂(SAM)和钙镁磷肥(CMP1)处理土壤p H增加了1.25和0.92个单位,土壤速效磷含量分别增加了3.1倍和2.6倍,土壤有效铁、有效锰、交换性H+、Al3+含量均大幅下降。SAM与CMP1处理通过提供足够的有效磷并补充钙、镁等元素,有效改善了根系生长环境,从而有效控制铁、锰、铝等元素向地上部转运,进而对作物的生长起到促进作用。SAM和CMP1处理较NPK处理有效促进了关键生育期水稻根系活力并显著增加了水稻籽粒产量,增幅分别达121.1%和105.1%。石灰效果次之。综上,初步认为碱性材料改良酸性硫酸盐土壤的关键在于保证了充足有效磷的同时,提高了土壤p H,降低了土壤金属的毒害。本试验条件下,钙镁磷肥对修复和改良酸性硫酸盐土壤障碍因子效果非常明显,但其成本是自研改良剂的3倍,因此,基于改良剂的成本与长期适用性考虑,自研改良剂可能是该类土壤改良的最佳选择。 相似文献