Soil zinc and its uptake by plants. II. Soil chemistry in relation to prediction of availability

Soil Research ◽  
1972 ◽  
Vol 10 (2) ◽  
pp. 165 ◽  
Author(s):  
KG Tiller ◽  
JL Honeysett ◽  
Vries MPC De
Keyword(s):  
Soil Chemistry ◽  
Zinc Concentration ◽  
Alkaline Soils ◽  
Acidic Soils ◽  
High Q ◽  
Unit Slope ◽  
Plant Data ◽  
Very High ◽  
Soil Groups ◽  
Soil Zinc

Representatives of nine soil groups were extracted with reagents that have been used to predict zinc deficiency. The amounts of soil zinc removed were discussed in terms of specific and non-specific bonding in relation to the reagent used. The desorption of natural zinc was also described in terms of the quantity/intensity (Q/I) relation and an equilibrium zinc concentration (ZnQ) at natural pH. The ZnQ values varied from 1 to 4 �gI. for the alkaline soils and 8-190 pg/l. for the acidic soils. The Q/I ratio was derived by radioisotopic and chemical isotherm procedures. Log Q/I (I = total soluble zinc) approximated closely a linear relation of unit slope with pH. This was ascnbed to a common reation of zinc with all soils by specific sorption dominated by ZnOHA ions such that Q/I� = constant where I' = (ZnOH+aq). Deviations from this relation are discussed. The relations between soil and plant (clover and wheat) variables were studied by simple and multiple regression analysis. Single values of intensity variables, and, to a lesser extent, Q/I variables, correlated well with plant data but not the quantity variables. The improved correlations of Q variables when combined with Q/I variables accorded with published work. The problem of predicting zinc availability on alkaline soils which are dominated by very high Q/I values, is discussed.

Soil zinc and its uptake by plants. I. Isotopic exchange equilibria and the application of tracer techniques. II. Soil chemistry in relation to prediction of availability

Soil Research ◽  
1972 ◽  
Vol 10 (2) ◽  
pp. 151 ◽  
Author(s):  
KG Tiller ◽  
JL Honeysett ◽  
Vries MPC De
Keyword(s):  
Isotopic Exchange ◽  
Specific Activity ◽  
Laboratory Data ◽  
Laboratory Method ◽  
Alkaline Soils ◽  
Acidic Soils ◽  
Activity Data ◽  
Podzolic Soils ◽  
Tracer Techniques ◽  
Soil Groups

Isotopic exchange studies were applied to the laboratory and glasshouse measurement of labile zinc in 25 soils from nine Great Soil Groups. The laboratory equilibration procedures worked well with acidic and most near neutral soils, but may overestimate labile zinc values for the lateritic podzolic soils. The values for some acidic soils were also compromised because of lack of isotopic equilibrium. The laboratory method gave erratic and unrealistic data when applied to alkaline soils due to fixation of the added zinc. The procedures based on the specific activity of zinc absorbed by plants from soils equilibrated with carrier-free 65Zn gave reproducible values of the total amount of plant available zinc for all soils. These values agree well with the corresponding laboratory data for acidic soils. Furthermore, the specific activity data showed that magnesium chloride and EDTA extractions had equilibrated with the same chemical form or forms of zinc as that absorbed by the plants.

Very high Q microwave spectroscopy on trapped /sup 171/Yb/sup +/ ions: application as a frequency standard

1995 ◽  
Vol 44 (2) ◽  
pp. 113-116 ◽  
Author(s):  
P.T.H. Fisk ◽  
M.J. Sellars ◽  
M.A. Lawn ◽  
C. Coles ◽  
A.G. Mann ◽  
...  
Keyword(s):  
Frequency Standard ◽  
Microwave Spectroscopy ◽  
High Q ◽  
Very High

Exchangeable Ions

2016 ◽  
Author(s):  
Garrison Sposito
Keyword(s):  
Soil Analysis ◽  
Metal Cations ◽  
Alkaline Soils ◽  
Charge Balance ◽  
Surface Excess ◽  
Acidic Soils ◽  
Soil Humus ◽  
Proton Charge ◽  
Definition Of ◽  
Particulate Soil

In Section 3.4, the cation exchange capacity, or CEC, of particulate soil humus is defined as the maximum number of moles of proton charge per kilogram that can be desorbed by a metal cation under prescribed conditions. Thus, CEC for particulate humus is equal to the maximum absolute value of the negative net proton charge. Operationally, this maximum value is measured typically as the surface excess of Ba2+ adsorbed by humus at pH 8.2 (Eq. 3.5). Extending this concept to soils, one can define the CEC as the maximum number of moles of readily exchangeablemetal cation charge per unit mass of dry soil that can be extracted under prescribed conditions. In this more general context, CEC refers to metal cations that adsorb on soil particles in either outer sphere surface complexes or the diffuse ion swarm (Fig. 7.2). In alkaline soils, the common readily exchangeable cations are Ca2+, Mg2+, Na+, and K+, whereas in acidic soils, this group expands to include Al3+, and its complexes AlOH2+, Al(OH)2+, and AlSO+4. Following the operational paradigm for soil humus, one concludes that the measurement of soil CEC involves not only the desorption of protons, but also the replacement of the population of readily exchangeable adsorbed metal cations at a selected pH value (usually pH 7–8) by a chosen cation. Laboratory procedures for measuring CEC are described in Methods of Soil Analysis, listed in For Further Reading at the end of this chapter. In alkaline soils, the replacing cation chosen is often Na+ or Ca2+, whereas in acidic soils and for soil humus, the replacing cation of choice is Ba2+. These cations, in turn, are typically displaced from soil particle surfaces by Mg2+ to measure the surface excess. A conceptual definition of CEC can be developed in terms of the surface charge balance concepts introduced in Chapter 7. Consider first a soil in which a net positive surface excess of anions does not occur, such as the Mollisol example discussed in Section 8.1. In this case, the only adsorbed ions are Ca2+ and Cl-. The CEC of this soil may be defined by a special case of the charge-balance condition in Eq. 7.3a: ∆qex (max) ≡ CEC

Lime chlorosis and other factors affecting the distribution of Eucalyptus on coastal sands in Southern Australia

1967 ◽  
Vol 15 (1) ◽  
pp. 95 ◽  
Author(s):  
RF Parsons ◽  
RL Specht
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
The Other ◽  
Alkaline Soils ◽  
Acidic Soils ◽  
Calcareous Sand ◽  
Factors Affecting ◽  
Physiological Tolerance ◽  
Calcareous Sands ◽  
Beach Sands

In southern Australia, deep calcareous and deep siliceous sands each carry a distinctive assemblage of eucalypts. Three of these species with contrasting edaphic ranges were investigated: Eucalyptus baxteri, which is widespread on acidic soils and is never found on highly alkaline soils like the calcareous sands; E. incrassata, which is widespread on acidic and neutral soils, occurs occasionally on some highly alkaline soils, but is also absent from calcareous beach sands; and E. diversifolia, which is found on both acidic and highly alkaline soils and is widespread on calcareous beach sands. All three species occur on siliceous sands, with E. baxteri in wetter areas than the other two species. Comparative pot experiments in which typical calcareous and siliceous sands were used showed that: (1) E. baxteri is stunted by severe lime chlorosis when grown on calcareous sand, while the other two species are not affected. (2) E. baxteri markedly outyields the other two species on siliceous sands. It is suggested that E. baxteri is absent from calcareous sands because it is physiologically intolerant of highly alkaline soils, and that E. baxteri replaces the other two species on the wetter siliceous sands because its faster growth rate enables it to outcompete them when rainfall is adequate. However, the slower growth rates of E. diversifolia and E. incrassata will be accompanied by slower rates of water use and this may give them an advantage over E. baxteri on drier siliceous sands. The wide edaphic range of E. diversifolia is considered to be the outcome of the wide physiological tolerance of individual plants rather than of intraspecific differentiation.

Exact trapping state dynamics for the 85Rb atom micromaser at very high Q and/or very low T

1996 ◽  
Author(s):  
Amitabh Joshi ◽  
A. Kremid ◽  
N. Nayak ◽  
B. V. Thompson ◽  
R. K. Bullough
Keyword(s):  
High Q ◽  
Very High ◽  
Trapping State

A loss mechanism study of a very high Q silicon micromechanical oscillator

2005 ◽  
Vol 97 (2) ◽  
pp. 023524 ◽  
Author(s):  
Xiao Liu ◽  
J. F. Vignola ◽  
H. J. Simpson ◽  
B. R. Lemon ◽  
B. H. Houston ◽  
...  
Keyword(s):  
Mechanism Study ◽  
Loss Mechanism ◽  
High Q ◽  
Very High

scholarly journals VULNERABILIDADE QUÍMICA DOS SOLOS A CONTAMINAÇÃO POR CHUMBO, EM ÁREA COM EXTRAÇÃO E CALCINAÇÃO DE CALCÁRIO NO ESTADO DE MINAS GERAIS – BRASIL.

2013 ◽  
Author(s):  
Adriano F. de Moraes ◽  
Adolf H. Horn
Keyword(s):  
Soil Chemistry ◽  
Minas Gerais ◽  
Microsoft Office ◽  
Soil Constituents ◽  
Very High

Entender a contaminação por chumbo demanda conhecer o seu comportamento e dos constituintes dos solosque interagem com ele. Foi estudada a Província Cárstica de Arcos-Pains-Doresópolis (MG). Mediram-seos teores de chumbo e a vulnerabilidade química do solo. As amostras foram analisadas na UFMG e UFV.Os resultados foram trabalhados em Microsoft Office Excel 2003 e ArcGis 9.2. Os teores de chumbosuperaram os valores de prevenção (72,0 mg/kg). Numa amostra, o teor (216,5 mg/kg) ultrapassou osvalores de intervenção agrícola (180,0 mg/kg). Nos solos hidromórficos a vulnerabilidade química é muitoalta indicando restrições de usos que lancem chumbo.Palavras-chave: calcários, solos e chumbo. ABSTRACT: Understanding the contamination by lead demand known its behavior and soil constituents that interact withit. It studied the Karstic Province of Arcos-Pains-Doresópolis (MG). It is quantified the levels of lead andvulnerability soil chemistry. The samples were analysed in UFMG and UFV. The results were worked outin Microsoft Office Excel 2003 and ArcGis 9.2. The levels of lead exceeded the values of prevention (72.0mg/kg). In a sample the content (216.5 mg / kg) exceeded the values of agricultural intervention (180.0 mg/kg). In the wet (hidromorfics) soil the vulnerability chemistry is very high indicating restrictions of usesto launch lead.Keywords: limestones, soils and lead.

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