Measurement of actinide, fission and daughter product contamination in prairie soil

2005 ◽  
Vol 264 (2) ◽  
pp. 463-467 ◽  
Author(s):  
W. S. Andrews
Keyword(s):  
Daughter Product ◽  
Prairie Soil ◽  
Actinide Fission

Rhizosphere populations of Rhizobium strains and nodulation of Leucaena leucocephala

1982 ◽  
Vol 22 (117) ◽  
pp. 293 ◽  
Author(s):  
HVA Bushby
Keyword(s):  
Nitrogen Fixation ◽  
Sandy Soil ◽  
Leucaena Leucocephala ◽  
Field Experiments ◽  
Podzolic Soil ◽  
Population Level ◽  
Nodule Formation ◽  
Seed Inoculation ◽  
Rhizobium Strains ◽  
Prairie Soil

Populations of two Rhizobium strains (NGR8 and CB81) in the rhizosphere of Leucaena leucocephala were estimated in field experiments with varying levels of antibiotically marked strains as seed inoculation treatments. The population level varied with soil type and strain of Rhizobium. Multiplication in the rhizosphere was very slow in a prairie soil but was more rapid in a sandy podzolic soil and nodulation was three weeks earlier in the sandy soil than in the prairie soil. Survival of these two strains in soil stored in the laboratory also suggested that they (especially NGR8) were not well suited to the prairie soil. Nodule representation of strain CB81 on the prairie soil decreased from 100% three months after sowing to between 12% and 16% two years after sowing. The results suggest that on this soil indigenous rhizobia form effective nitrogen fixing associations with Leucaena leucocephala and that any improvement in nitrogen fixation will require strains of Rhizobium that are more effective than the indigenous strains and better competitors for nodule formation.

scholarly journals Pipeline Impacts and Recovery of Dry Mixed-Grass Prairie Soil and Plant Communities

2020 ◽  
Vol 73 (5) ◽  
pp. 619-628
Author(s):  
M. Anne Naeth ◽  
David A. Locky ◽  
Sarah R. Wilkinson ◽  
Meghan R. Nannt ◽  
Candace L. Bryks ◽  
...  
Keyword(s):  
Plant Communities ◽  
Mixed Grass Prairie ◽  
Prairie Soil ◽  
Mixed Grass

Pseudogley in Gundaroo Subsola, Southern Tablelands, New South Wales

Soil Research ◽  
1969 ◽  
Vol 7 (2) ◽  
pp. 143 ◽  
Author(s):  
Dijk DC Van
Keyword(s):  
New South ◽  
New South Wales ◽  
Soil Layer ◽  
South Wales ◽  
Prairie Soil ◽  
Red Earth

The genesis is discussed of a range of pedological differentiations which occur unusually deep in the soil and characterize low, but not the lowest, catenary segments of the Gundaroo pedomorpholith. This soil layer forms a large part of the soil mantle on the Southern Tablelands and is of considerable age. The deep-seated differentiations have developed as separate 'accessory' features below red-yellow and meadow podzolic, prairie soil, and red-earth sola of normal depth (2-4 ft). The zone in which they occur is termed the 'subsolum'. The features are dominated by vertical patterns related to planar and tubular voids. They include, besides a range of sesquioxidic forms, conspicuous clay differentiations comprising pronounced cutans and up to 1-1 1/2 in. wide vertical clay veins and well-developed pedality with thick colloid coatings. These features are believed to represent 'descendant' pseudogley and to be related to an unusually dynamic palaeoclimatic regime.

Oxidative alteration of Ce-rich pyrochlore: HRTEM/EELS investigation

1999 ◽  
Vol 556 ◽  
Author(s):  
Huifang Xu ◽  
Yifeng Wang
Keyword(s):  
Inner Mongolia ◽  
Diffusion Processes ◽  
Northern China ◽  
Alpha Decay ◽  
Daughter Product ◽  
Ore Deposit ◽  
Transmission Electron ◽  
Abundant Element ◽  
Electron Energy Loss ◽  
Aqueous Species

AbstractTransmission electron microscopy (TEM) and associated electron energy-loss spectroscopy (EELS) study show intergrowth of Ce4+-rich pyrochlore (metamict) and Ce3+-rich pyrochlore (partially metamict) in a Ce-rich pyrochlore from a rare earth element (REE) ore deposit of Inner Mongolia, Northern China. The partially metamict material is Ba-free and dominated by Ce3+. However, the metamict material is Ba-bearing and dominated by Ce3+,. The Ce4+-rich pyrochlore may result from radiation damage by alpha decay that also causes oxidation of Fe 2+ in titanite, and the interaction with a Ba-bearing oxidizing fluid. The oxidation of Ce3+ in the primary pyrochlore is accompanied by in the loss of REE, Ca, and Pb, a daughter product of U via alpha decay, during the alteration. However, most REE were incorporated in the alteration product, the Ce4+-rich pyrochlore. Based on EDS and EELS analyses, the chemical formulae of the partially metamict Ce3+-rich pyrochlore and metamict Ce4+-rich pyroeblore can be written as: (Ca, Ce3+, U, Pb) 2(Ti, Nb)2O7−x(OH)x, and (Ba, Ca, Ce4+, U)2 (Ti, Nb)2O7−y(OH)y, respectively. Ce is the most abundant element among all REE. It is proposed that the alteration takes place in solid-state with oxidizing fluid as a catalyst. The alteration kinetics is controlled by diffusion processes of aqueous species in metamict pyrochlore.

Studies in tropical soils: IV. Organic transformations in soils, composts and peat

1937 ◽  
Vol 27 (2) ◽  
pp. 162-177 ◽  
Author(s):  
D. W. Duthie
Keyword(s):  
Clay Soil ◽  
Tropical Soils ◽  
Tropical Soil ◽  
Soil Samples ◽  
Organic Transformations ◽  
Surface Layers ◽  
Prairie Soil ◽  
Nitrogenous Substances ◽  
Chemical Characters ◽  
Organic Decomposition

1. Waksman's simplified scheme of fractionation was used in attempts to trace the organic transformations occurring in some tropical samples of composts, soils and peats.2. It was found that a useful partition of the nitrogenous substances into hydrolysable and resistant fractions could be effected by boiling with 5 per cent sulphuric acid for 6 hours.3. Two profile layers of a black calcareous Trinidadian clay soil were compared with two horizons of a prairie soil examined by Waksman & Stevens. The surface layers of both soils were found to be similar in chemical characters, but the lower subsoil layers of the Trinidadian soil gave evidence of a more advanced and profound degree of organic decomposition.4. Serial soil samples, taken from eight undisturbed natural profiles representative of humid tropical soil types occurring in Jamaica and Trinidad, were similarly examined.

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