C - Lublin

More documents

Recommendations

Info

magnetic (ferrimagnetic) oxides, magnetite and maghemite – usually in concentrations indetectable by XRD but easily measurable by routine magnetic methods of analysis. Hence, magnetic analyses of soils provide an additional, sensitive window on soil iron and its response to climate. Statistical examination of the relationships between magnetic properties of modern steppe soils from transect spanning the loess plain from the Caspian Sea to the North Caucasus and major climate variables identifies annual rainfall as the most significant factor (R2 = 0.93) (Maher et al., 2003). Soil formation in the steppe zone produces dispersed ferrimagnetic minerals (magnetite and maghemite) with particle size of predominantly
Fig.1. Iron Oxides Magnetic Mineralogy and climate relationship – SIRM(magnetite) and HIRM100mTaf (haematite, goethite) for parent materials (pm) and representative soil samples versus annual rainfall The biogeochemical cycle of iron at neutral pH in steppe soils, with formation of secondary ferrimagnetic minerals may follow the following sequence: the flux of Fe from primary Fe bearing minerals to the microbiologically active zone as a function of intensity of weathering; poorly crystalline hydrous ferric oxide (ferrihydrite) formation by iron bacteria (Gallionella sp.; Leptotrix sp.,Toxothrix sp) in oxidizing conditions. Higher oxidation rates, higher organic matter and lower pH (~ 4-6) predispose formation of goethite, whilst haematite is favoured by higher temperatures, decreased water activity and higher pH (~7–8) (Schwertmann, 1988). In soils, magnetite formation requires the initial presence of some Fe 2+ cations. Even in generally well-drained and oxic soils, like the steppe soils, Fe 2+ can be formed in soil micro-zones, made temporarily anoxic during periods of soil wetness, via the activity of iron-reducing bacteria (Geobacter sp., Shewanella sp., et al). In locally anoxic condition poorly crystalline hydrous ferric oxide will be reduced by iron reducing bacteria with formation of magnetite or siderite. Intermittent wetting and drying of soils will thus predispose formation of magnetite, in the presence of organic matter and a weathering source of iron. To produce a ‘constant’ grain size distribution (as in the steppe soils), magnetite formation must thus be initiated under ‘constant’ environmental conditions. Such constancy in the natural environment can be explained if the bacteria which produce the required Fe 2+ only operate within, and/or create via their metabolism, a certain set of pH, Eh and Fe conditions. In contrast to these optimal magnetiteforming conditions, longer periods of dryness, with increased oxidation rates and 13
Page 2 and 3: PHYSICS, CHEMISTRY AND BIOGEOCHEMIS
Page 4 and 5: IN MEMORIAM Dr Ludmila Petrovna Kor
Page 8 and 9: educed water activity, would favour
Page 10 and 11: In this paper AT sorption by surfac
Page 12 and 13: were obtained with clay content, pH
Page 14 and 15: In present investigation the quartz
Page 16 and 17: Hence, the micromorphology suggests
Page 18 and 19: As the indicators of soil aeration
Page 20 and 21: Stomatal diffusive resistance of th
Page 22 and 23: indicators of soil aeration conditi
Page 24 and 25: REFERENCES 1. 2. 3. 4. 5. 6. 7. 8.
Page 26 and 27: Table 1. Breakdown of numbers and t
Page 28 and 29: MORPHOLOGICAL AND PHYSICOCHEMICAL P
Page 30 and 31: conditions, existing at the first p
Page 32 and 33: INFLUENCE OF TEMPERATURE ON WATER P
Page 34 and 35: moisture % 100 90 80 70 60 50 40 so
Page 36 and 37: STATE OF MICROBIAL COMMUNITIES IN M
Page 38 and 39: million cells/g soil 25 20 15 10 5
Page 40 and 41: THE INFLUENCE OF COMPOSITION AND PR
Page 42 and 43: days grew faster than on substrate
Page 44 and 45: SOIL SALINITY AND CLIMATE CHANGES I
Page 46 and 47: POROUS STRUCTURE OF NATURAL BODIES
Page 48 and 49: These nonuniform classification sys
Page 50 and 51: Mercury intrusion data are plotted
Page 52 and 53: METHOD AND MATERIALS The shear stre
Page 54 and 55: wheat flour NaCl salt fine milk Fig
Page 56 and 57:
The shear experiments revealed two
Page 58 and 59:
Variable charge of mineral surfaces
Page 60 and 61:
3. Huffaker RC and Wallace A 1958 P
Page 62 and 63:
Q V (pH)/N t = α(pH) = n ∑ i= 1
Page 64 and 65:
REFERENCES 1. De Wit, J.C.M, Van Ri
Page 66 and 67:
BM - biomass; NM - necromass; MM -
Page 68 and 69:
thousand times at the absence of co
Page 70 and 71:
. m 131.5 131.0 I Height above sea
Page 72 and 73:
SEASONAL VARIABILITY OF SOIL WATER
Page 74 and 75:
The mean difference (MD) and the ro
Page 76 and 77:
Acknowledgement This paper presents
Page 78 and 79:
1992; Selim 1999). The relative imp
Page 80 and 81:
1.0 C rel 0.5 0.0 v=0.7 D=3.28 v=0.
Page 82 and 83:
1.0 a b C rel 0.5 0.0 0 1 2 3 0 1 2
Page 84 and 85:
Comparison of before- and after-pul
Page 86 and 87:
provides the accessibility of catio
Page 88 and 89:
MODEL RESEARCH ON FORMATION OF SYNT
Page 90 and 91:
The analysis of the specific surfac
Page 92 and 93:
PHOSPHATE-INDUCED CHANGES IN THE SP
Page 94 and 95:
According to the data of Table 1, t
Page 96 and 97:
MINERAL-ORGANIC COMPOUND OF SOILS:
Page 98 and 99:
RESULTS AND DISCUSSION An analysis
Page 100 and 101:
INTRODUCTION CHEMICAL DEGRADATION O
Page 102 and 103:
of organic particles and their elec
Page 104 and 105:
HNO 3 -extractable form is very clo
Page 106 and 107:
Results demonstrated that Pb and Cd
Page 108 and 109:
tion was measured using the Tjurina
Page 110 and 111:
OUTPUT FLUXES OF LEAD IN FOREST ECO
Page 112 and 113:
Regional data on Pb concentrations
Page 114 and 115:
DEVICE FOR EVALUATION OF THE RAPE P
Page 116 and 117:
SPECTROSCOPIC COMPARISON OF HUMIC A
Page 118 and 119:
ehavior of sequentially extracted H
Page 120 and 121:
MODERN MONITORING SYSTEMS FOR THE M
Page 122 and 123:
The control of the measurement syst
Page 124 and 125:
ASORPTION AND SURFACE AREA OF SOILS
Page 126 and 127:
Nm xCBET N = ( 1− x BET − )[ 1+
Page 128 and 129:
According to this, when x/N (1-x) i
Page 130 and 131:
POTENTIAL OF AZOLLA CAROLINIANA TO
Page 132 and 133:
The decrease of Pb(II) and of Cd(II
Page 134 and 135:
12. 13. 14. 15. 16. Piechalak, A.,
Page 136 and 137:
Kloc, 2001]. Nitrogen adsorption is
Page 138 and 139:
This is worth noting that the lower
Page 140 and 141:
N ( h) 1 2 γ ( h) = [ ( ) ( )] ( )
Page 142 and 143:
Exemplary spatial distributions (sa
Page 144 and 145:
This is worth noting that significa
Page 146 and 147:
adsorbed chemicals to microorganism
Page 148 and 149:
were detected in the untreated soil
Page 150 and 151:
0.4 1000 Moisture [Vol.] 0.3 0.2 0.
Page 152 and 153:
NITROUS OXIDE EMISSION FROM SOILS W
Page 154 and 155:
N2O-N [mg kg -1 ] 100 80 60 40 20 0
Page 156 and 157:
LITERATURE 1. 2. 3. 4. 5. 6. 7. 8.
Page 158 and 159:
where v(t) - CO 2 production rate;
Page 160 and 161:
carbon was involved mainly into mic
Page 162 and 163:
Demkin Vitaliiy DrSc Dmitrakov Leon
Page 164 and 165:
Priputina Irina PhD Rudko Tadeusz P
show all

C - Lublin

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?