植物營養(yǎng)元素的土壤化學(xué)-土壤中的微量元素.ppt

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1、第六章 土壤微量元素 Chapter 6 Micronutrients in Soil,高等植物必需的營養(yǎng)元素（16+1 或+2）,C,H,O,N,P,K,Ca,Mg,S, Cu,Zn,Mn,Fe,B,Mo,CI,,Ni，Co,大量元素,微量元素,Other elements, such as silicon (Si), vanadium (V), and sodium (Na), appears to improve the growth of at least certain plant species. Animals, including humans, also requires m

2、ost iodine (I), and fluorine (F), have been shown to be essential for animal growth but are apparently not required by plants.,Intensive plant production practices have increased crop yields, resulting in greater removal of micronutrients from soils. The trend toward high-analysis fertilizers has re

3、duced the use of impure salts and organic manures, which formerly supplied significant amounts of micronutrients. Increased knowledge of plant nutrition and improved methods of analysis in the laboratory are helping in the diagnosis of micronutrient deficiencies that might formerly have gone unnotic

4、ed. Increasing evidence indicates that food grown on soils with low levels of trace elements may provide insufficient human dietary levels of certain elements, even though the crop plants show no signs of deficiency themselves.,為何微量元素營養(yǎng)問題越來越重要？,The extent of micronutrient-deficient soils are compara

5、ble to that of nitrogen-, phosphorus-, and potassium-deficient soils. Summary data (Table 1) from an extensive effort that examined 190 soil samples from 15 countries revealed that 49% of these soils were low in zinc and 31% low in boron (Sillanpaa, 1990).,,Today, there are over 3.7 billion iron-def

6、icient individuals and about 1 billion people that are or are at risk of developing iodine deficiency disorders. Additionally, there are over 200 million people that are vitamin A deficient (World Health Organization, 1999). Other micronutrient deficiencies (e.g., Zn, Se, vitamin C, vitamin D, and f

7、olic acid deficiencies) may be as wide spread as iron, iodine and vitamin A deficiencies, but there are no reliable data to confirm this although circumstantial evidence suggests that this may be so (Combs et al., 1996; World Health Organization, 1999).,Welch R M. The impact of mineral nutrients in

8、food crops on global human health. Plant and Soil 247: 8390, 2002.,對(duì)人體健康的影響？,Figure 1. Global distribution of Fe, vitamin A and I deficiencies (map modified from Sanghvi, 1996).,Toxicity of some micronutrient in soils.,Expanding interests in the field of heavy metal research were associated with inc

9、reasing world-production of metals and their common usage in the past century, and consequently, with their increasing emissions into the environment. This resulted in growing hazard to humans health posed by elevated metal concentrations in air, water, and food.,The most important sources of heavy

10、metals in soils are those connected with anthropogenic activities, such as metal mining and smelting, production and usage of pesticides and wood preservatives, waste processing and disposal, etc.,Characteristics of micronutrient nutrition,需要量少，但不可替代 缺乏多呈一定的區(qū)域性 適宜濃度范圍較窄,微量元素的生物地球化學(xué)循環(huán) 土壤中不同微量元素的含量、形態(tài)

11、、轉(zhuǎn)化及有效性 土壤微量元素與地方病 微量元素污染及治理,1.微量元素的生物地球化學(xué)循環(huán),生物地球化學(xué)循環(huán)(Biogeochemical cycle),生態(tài)系統(tǒng)從大氣、水體及土壤等環(huán)境中獲得營養(yǎng)物質(zhì)，通過綠色植物吸收，進(jìn)入生態(tài)系統(tǒng)，被其它生物重復(fù)利用，最后再歸還于環(huán)境的過程。,,生物地球化學(xué)循環(huán)的過程研究主要是在生態(tài)系統(tǒng)水平和生物圈水平上進(jìn)行的。,生產(chǎn)者 消費(fèi)者 分解者 非生物環(huán)境（無機(jī)環(huán)境）,生物地球化學(xué)循環(huán)的類型,氣體型循環(huán) 沉積型循環(huán),氣體型循環(huán) 沉積型循環(huán),微量元素的生物地球化學(xué)循環(huán),氯，溴，氟等循環(huán)。,鐵，錳，銅，鋅等循環(huán),Humans have long influenced Zn

12、 inputs to soils. Two thousand years ago, approx. 10 000 tones Zn yr1 were emitted as a result of mining and smelting activities . Since 1850, emissions have increased 10-fold, peaking at 3.4 Mt Zn yr1 in the early 1980s, and then declining to 2.7 Mt Zn yr1 by the early 1990s. The ratio of Zn emissi

13、ons arising from anthropogenic and natural inputs is estimated to be 20:1.,人類活動(dòng)對(duì)微量元素循環(huán)的影響,Other anthropogenic inputs of Zn to soils： fossil fuel combustion, mine waste, phosphatic fertilizers (typically 501450 g Zn g1), limestone (10450 g Zn g1), manure (15250 g Zn g1), sewage sludge (91 49 000 g Zn

14、 g1), other agrochemicals particles from galvanized (Zn-plated) surfaces and rubber mulches.,土壤中微量元素的循環(huán),2. Contents, forms and availability of micronutrients in soils,The initial trace element content of soils reflects the materials from which they form, but pedogenic processes and landscape age int

15、roduce much variation.,Iron, Zn, Mn, and Cu are somewhat more abundant in basalt; B and Mo are more concentrated in granite.,花崗巖 玄武巖 頁巖 石灰石 砂巖 輝長巖 斜長石 輝石 橄欖石,Advances including the global positioning system (GPS), geographic information systems (GIS), inductively coupled plasma (ICP) spectrometry, g

16、eostatistics, and precision agriculture facilitate soil micronutrient mapping and provide quantitative support for decision and policy making to improve agricultural approaches to balanced micronutrient nutrition.,Mapping soil micronutrients,Field Crops Research, 60 (1999) 11-26,Example,Fig. 5. Map

17、of kriged estimates of total soil zinc for the conterminous USA classed by deciles using data from USGS and USEPA soil studies (White et al., 1997). Crosses indicate sites of three high-zinc outliers excluded from the USGS data set.,Example,Fig. 3. Geographic distribution of low-, variable-, and ade

18、quate-selenium areas in the USA (after Kubota and Allaway, 1972).,Weathering of underlying parent materials, Natural processes (e.g., gases from volcanic eruption, rain/snow, marine aerosols, continental dust, forest fires Anthropogenic processes (industrial and automobile discharges, addition of fe

19、rtilizers, lime, pesticides, manures, sewage sludges).,Available micronutrients in soil are derived from:,Forms of micronutrients dominant in the soil solution,B Zn Mn Fe Cu Mo CI Co Ni,H3BO3, H2BO3- Zn2+，Zn(OH)+ Mn2+ Fe2+, Fe(OH)2+, Fe(OH)2+, Fe3+ Cu2+, Cu(OH)+ MoO42-, HMoO4- CI- Co2+ Ni2+,Ni3+,,,I

20、t is bio-available metal species present in soil solution rather than high amounts of metals in solid phase that cause adverse biological effects on soil biota, control the uptake of metals by higher plants, and their input into the food chain.,Speciation of trace metals,Speciation (in the context o

21、f soils) refers to both the process and the quantification of the different defined species, forms and phases of a trace element. The speciation of trace metals in soils is related to their biogeochemical reactivity and to several physicochemical conditions of the soil.,Water-soluble As free cation

22、As complexes with organic and inorganic ligands On exchange sites of clay minerals (can be extracted with a weak exchanger, such as NH4+) Specifically adsorbed (Some trace elements (e.g., Cu2+) are retained by clay minerals and/or Fe and Mn oxides in the presence of a large excess of Ca2+ or some ot

23、her electrostatically bounded cation) Adsorbed or complexed by organic matters As insoluble precipitates, including occlusion by Fe and Mn oxides As the primary minerals,Forms of micronutrients in soil,Fractionation of micronutrients in soil,The sequential fractionation scheme: Based on the ability

24、of certain solvents to remove specific bound forms of the metal.,Forms of Copper,Stevenson FJ, 1986. pp-342,土壤中一些金屬離子可與土壤中存在的有機(jī)物，如腐殖質(zhì)、蛋白質(zhì)、有機(jī)酸等絡(luò)合。,有機(jī)物中具有絡(luò)合作用的基團(tuán)?,羥基 OH 羧基 COOH 羰基 =CO 氨基 NH2 亞氨基=NH,穩(wěn)定常數(shù)越大，金屬離子與絡(luò)合劑結(jié)合的能力越強(qiáng)，形成的絡(luò)合物越穩(wěn)定。,Nutrients in chelate forms,Nutrients in chelate forms,EDTA:乙二胺四乙酸 HEDT

25、A:羥乙基乙二胺三乙酸 EDDHA:乙二胺二鄰位苯酚乙酸,Table Stability constants (Log K) for selected chelating agents and nutrient cations,Brady NC, Well RR. 1996,Availability of micronutrients in soil,Uptake of micronutrients by plant is largely dependent on the availability of these elements in soils. The availability of

26、micronutrients is not only related to the total contents of these elements in soil, but also to soil properties, such as soil pH, Eh, and texture, etc.,Highly leached, acid, sandy soils Organic soils Soils of very high pH Soils that have been very intensively cropped and heavily fertilized with macr

27、onutrient only,Micronutrients are most apt to limit crop growth in,黃土高原地區(qū)土壤多數(shù)微量元素含量分布具有明顯的從西北向東南逐漸增加的趨勢。(其中B、Mo由西北向東南含量增加的趨勢不明顯),黃土高原地區(qū)不同微量元素的含量水平：,鋅、錳含量中等偏低 銅、硼中等 鉬的含量很低,原因？,1) CK (對(duì)照,N 60 kg/ hm2 + P 26. 4 kg/ hm2) ; 2) Zn ( NP, 施Zn , ZnSO4 15 kg/ hm2) ; 3) Mn (NP, 施Mn ,MnSO4 22.5 kg/ hm2) 4) Cu (

28、NP, 施Cu , CuSO4 15 kg/ hm2),長期施用微量元素肥料對(duì)土壤微量元素有效性的影響 （mg/kg）,1984-2003 陜西 長武 (郝明德等, 2006),基性火成巖發(fā)育的土壤含鋅量高于酸性巖,礦質(zhì)態(tài)鋅 交換態(tài)鋅 水溶性鋅,含鋅的礦物有：閃鋅礦、紅鋅礦、菱鋅礦等。 90%,2.1 Zinc(Zn),Exchangeable Zn typically ranges from 0.1 to 2 g Zn g1,Concentrations of water-soluble Zn in the bulk soil solution are low, typically betw

29、een 41010 and 4106 M (Barber, 1995),,Soil Zn fractions in the solid phase can be quantified using sequential extractions or isotopic dilution techniques (Young et al., 2006).,(Miller Seafoods including fishHg; Unwashed, hairy, leafy vegetablesPb (especially in urban areas); Drinking waterAs.,生物治理方法,

30、養(yǎng)分/元素的吸收及在植物內(nèi)的運(yùn)輸,Soil,Root,Shoot,Grain or fruit,,,,,,Hyperaccumulation,Thlaspi caerulescens (Brassicaceae)（遏蘭菜） hyperaccumulator of Zn, Cd, (Pb) and Ni on Zn wastes in Belgium.,Some hyperaccumulators,Picture from Alan Baker,植物修復(fù)的機(jī)理,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,Phytostabilization,Phyto

31、degradation And/or Rizofiltration,Phytoextraction,Phytovolatilization,,,,,,,,,,浙江大學(xué) 楊肖娥教授,In principle, phytoremediation includes:,Phytoextraction: heavily contaminated soils; Phytostabilisation: moderately contaminated soils Phytofiltration: lightly contaminated agricultural soils Phytodegradation:

32、 organic contaminants-rhizosphere remediation; Phytovolitilisation: some metals, Hg, Se etc.,References,土壤植物營養(yǎng)學(xué)原理和施肥，魯如坤等，化學(xué)工業(yè)出版社，北京，1998 劉錚. 微量元素的農(nóng)業(yè)化學(xué). 農(nóng)業(yè)出版社，1991 余存祖. 中國旱地的微量元素管理. 李生秀編. 中國旱地農(nóng)業(yè)，農(nóng)業(yè)出版社，2004. pp:433-482 Mortvedt JJ, Cox FR, Shuman LM, Welch RM. Micronutrients in Agriculture, 2nd edn, SSSA, Madison, WI , 1991 Stevenson FJ. Cycles of Soil: Carbon, Nitrogen, Phosphorus, Sulfur, Micronutrients. John Wiley & Sons, 1986 Mengel K, Kirkby E A. Principles of Plant Nutrition. IPI, Bern, Switzerland,1987.,