Procedure for the Determination of Exchangeable Copper and Molybdenum in Podzol Soils

Gupta, Umesh C.; MacKay, D. C.

doi:10.1097/00010694-196602000-00003

Cited by 46 publications

(16 citation statements)

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“…Two soil suspensions were prepared for each sample. The soil mixtures were equilibrated by shaking in a reciprocal shaker at 100 strokes min -1 for 5 h, a technique based on batch extraction studies by Gupta and Mackay (1986). After equilibrium, soil solids were separated from the solution by centrifugation and then by filtration through a 0.45 lm pore-size membrane filter.…”

Section: Soil and Bedrock Extractsmentioning

confidence: 99%

Drought’s impact on Ca, Fe, Mg, Mo and S concentration and accumulation patterns in the plants and soil of a Mediterranean evergreen Quercus ilex forest

2007

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We conducted a 6-year field manipulation drought experiment in an evergreen Quercus ilex forest where we simulated the drought predicted by GCM and ecophysiological models for the coming decades (an average of 15% soil moisture reduction). We thereby tested the hypothesis that enhanced drought will change Ca, Fe, Mg, Mo and S availability, concentrations and accumulation patterns in Mediterranean ecosystems. The strongest effects of drought occurred in the soil. Drought increased the total soil concentrations of S, the soil extract concentrations of Fe, Mg and S, the Mg saturation in the soil exchangeable complex and tended to increase the percentage base saturation of the soil exchangeable complex. These increased soil concentrations were related to a decrease of plant uptake capacity and not to an increase of soil enzyme activity, which in fact decreased under drier conditions. Drought increased leaf Mg concentrations in the three dominant species although only significantly in Quercus ilex and Arbutus unedo (20 and 14%, respectively). In contrast, drought tended to decrease Ca in Phillyrea latifolia (18%) and Ca and Fe concentrations in the wood of all three species. Drought increased Ca and Fe concentrations in the roots of Quercus ilex (26 and 127%). There was a slight general trend to decrease total biomass accumulation of nutrients that depend on water flux such as Mg, Fe and S. This effect was related to a decrease of soil moisture that reduced soil flow, and to a decrease in photosynthetic capacity, sap flow, transpiration and growth, and therefore plant uptake capacity under drought observed in Quercus ilex and Arbutus unedo. On the contrary, drought increased Mo accumulation in aboveground biomass in Phillyrea latifolia and reduced Mo accumulation in Arbutus unedo by reducing growth and wood Mo concentrations (51%). Phillyrea latifolia showed a great capacity to adapt to drier conditions, with no decrease in growth, an increase of Mo uptake capacity and a decrease in leaf Ca concentration, which was related to a decrease in transpiration under drought. The results indicate asymmetrical changes in species capacity to accumulate these elements, which are likely to produce changes in inter-specific competitive relations among dominant plant species and in their nutritional quality as food sources. The results also indicate that drought tended to decrease nutrient content in aboveground biomass, mainly through the decrease in growth and transpiration of the most sensitive species and caused an increase in the availability of these nutrients in soil. Thus, drought decreased the ecosystem's capacity to retain Mg, Fe and S, facilitating their loss in torrential rainfalls.

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Section: Soil and Bedrock Extractsmentioning

confidence: 99%

Drought’s impact on Ca, Fe, Mg, Mo and S concentration and accumulation patterns in the plants and soil of a Mediterranean evergreen Quercus ilex forest

2007

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“…fn general, cereal crops are most sensitiye to low Cu in soils or in culture solutions (8,10). Experiments (4). The crops used were: wheat (Triticum vulgare L., cultivar Opal), barley (Hordeum distichon L., cultivar Herta) and oats (Avena sativaL., cultivar Cabot).…”

Section: Introductionmentioning

confidence: 99%

Response to Copper and Optimum Levels in Wheat, Barley and Oats Under Greenhouse and Field Conditions

Gupta¹,

MacLeod²

1970

Can. J. Soil. Sci.

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“…The procedure to evaluate the ionic strength effect on Cu desorption was: 2 g of soil sample were transferred to 50-mL polyethylene tubes and 20 mL of 0.01 and 0.001 mol L -1 CaCl 2 solutions were added (Hogg et al, 1993;Zhu & Alva, 1993). The soil was mixed with the solution and the suspension was left steady during 24h to reach equilibrium, as recommended by Gupta & Mackay (1966). The suspension was shaken for either 2, 4 or 8 hours to evaluate Cu desorption.…”

Section: Native Cu Adsorption and Desorptionmentioning

confidence: 99%

“…The added Cu desorption, by adding CuCl 2 , was proceeded in soil samples with two pH values (4.5 and 7.5) and evaluated during three periods of soil/Cu incubation for either 24 hours, according to Gupta & Mackay (1966), 4 or 12 weeks (Hogg et al, 1993), with moisture content kept at 25% (soil field capacity). Hogg et al (1993), studying Cu adsorption in ten soils from New Zealand, concluded that a period of incubation of 12 weeks was adequate, because adsorption was very low afterwards.…”

Section: Adsorption and Desorption Of Added Cumentioning

confidence: 99%

Copper desorption in a soil with variable charge

Casagrande

Jordão²,

Alleoni³

et al. 2004

Sci. agric. (Piracicaba, Braz.)

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Adsorption processes of heavy metals in soils have been more extensively studied than desorption, in spite of this latter process being related to nutrient bioavailability in the soil solution. Copper desorption from surface (0-0.2 m) and subsurface (1.0 -1.2 m) samples of an Anionic Acrudox was studied at two pH values (4.5 and 7.5). Soil samples were incubated with Cu rates varying from 0 to 400 mg kg Complete soil adsorption of added Cu was observed at pH 7.5 in all incubation periods, indicating that a 24h-shaking period was enough to reach equilibrium and maximum adsorption. Copper adsorption varied with the incubation period and was much lower at pH 4.5 than at pH 7.5, after the 24 hour-incubation period. After 4 and 12 weeks, Cu adsorption values were higher and similar for all soil samples, irrespective of pH or depth of sampling. The effect of the incubation period on soil Cu adsorption surpassed the pH effect for all Cu rates. The hysteresis was expressive, suggesting that Cu enhances high-energy bonds with the soil colloids. Calcium chloride was not efficient in promoting native soil Cu desorption in the studied concentrations. . No pH mais elevado (7,5), em todos os períodos de incubação, as amostras adsorveram praticamente todo o cobre adicionado, indicando que o tempo de 24 h de agitação para se atingir o equilíbrio foi suficiente para atingir a adsorção máxima. A adsorção de Cu variou com o tempo de incubação do elemento com o solo. No pH mais baixo (4,5), a adsorção foi bem menor após 24 h de incubação. Após 4 e 12 semanas, as adsorções foram elevadas e semelhantes para todas as amostras, independentemente da profundidade e do pH. Para todas as doses estudadas, o efeito do tempo de incubação na adsorção de cobre pelo solo sobrepujou o efeito do pH. O fenômeno de histerese foi expressivo, sugerindo que o Cu forma ligações de alta energia com os colóides do solo. O cloreto de cálcio não foi eficiente para dessorver cobre nativo do solo.

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Procedure for the Determination of Exchangeable Copper and Molybdenum in Podzol Soils

Cited by 46 publications

References 0 publications

Drought’s impact on Ca, Fe, Mg, Mo and S concentration and accumulation patterns in the plants and soil of a Mediterranean evergreen Quercus ilex forest

Drought’s impact on Ca, Fe, Mg, Mo and S concentration and accumulation patterns in the plants and soil of a Mediterranean evergreen Quercus ilex forest

Response to Copper and Optimum Levels in Wheat, Barley and Oats Under Greenhouse and Field Conditions

Copper desorption in a soil with variable charge

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