New Developments and Perspectives on Soil Potassium Quantity/Intensity Relationships

Evangelou, V. P.; Wang, Jian; Phillips, R. E.

doi:10.1016/s0065-2113(08)60624-0

Cited by 74 publications

(39 citation statements)

References 109 publications

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“…Observations on the change in free energy of exchange (DG) indicate that 80% of the farm soils and 67% of the greenhouse soils were K sufficient. This observation agrees with the findings of Roy et al (1991); Evangelou et al (1994); Jalali (2007). They reported that soils with DG greater than 3,500 kcal for the replacement of Ca and Mg with K are K deficient.…”

Section: Quantity/intensity Parameterssupporting

confidence: 93%

“…The Q/I relationship depicts the capacity of a soil system to maintain a certain level of K in solution and gives visual representation of how the level of K in Relative yield = (yield of minus K pots/yield of plus K pots) 9 100 solution is related to the amount of K available in the exchangeable and soluble forms (Evangelou et al 1994). Equilibrium activity ratio (ARoK) measures the availability or intensity of labile K in the soil.…”

Section: Quantity/intensity Parametersmentioning

confidence: 99%

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Potassium supplying capacity of some tropical alfisols in southwest Nigeria as measured by intensity, quantity and capacity factors

Taiwo¹,

Adetunji

Azeez

et al. 2009

Nutr Cycl Agroecosyst

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Experiments were conducted in the laboratory, greenhouse and on farmers' fields to determine, the potassium (K) supplying capacity of some soils in Ogun State, Nigeria, using equilibrium parameters as measured by quantity, intensity and activity indices. The result showed that the potassium status of the soils varied widely. Total K varied from 14.2 to 104 cmol kg -1 in the green house soils and 46.05 to 89.

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Section: Quantity/intensity Parameterssupporting

confidence: 93%

Section: Quantity/intensity Parametersmentioning

confidence: 99%

Potassium supplying capacity of some tropical alfisols in southwest Nigeria as measured by intensity, quantity and capacity factors

Taiwo¹,

Adetunji

Azeez

et al. 2009

Nutr Cycl Agroecosyst

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“…However, K þ release from clay minerals may also be related to redox processes. Potassium participates in cation exchange [Barshad, 1954] and may be displaced by NH þ 4 ions as they accumulate in anoxic pore water, causing K þ desorption [Evangelou et al, 1994]. The addition of NH þ 4 has also been found to increase the likelihood of K þ to participate in cation exchange with Ca 2þ and Mg 2þ [Lumbanraja and Evangelou, 1990].…”

Section: Patterns Of Biogeochemical Cycling Around Cross-vanesmentioning

confidence: 99%

“…The addition of NH þ 4 has also been found to increase the likelihood of K þ to participate in cation exchange with Ca 2þ and Mg 2þ [Lumbanraja and Evangelou, 1990]. On the other hand, the presence of SO 2À 4 ions causes a stronger binding of K þ to clays [Evangelou et al, 1994], so a reduction in SO 2À 4 concentration may also cause K þ desorption. Finally, it has been shown that the reduction of Fe(III) to Fe(II) in clay minerals causes a decrease in K þ sorption and an enhancement in the replaceability of K þ by Mg 2þ [Barshad and Kishk, 1968].…”

Section: Patterns Of Biogeochemical Cycling Around Cross-vanesmentioning

confidence: 99%

Spatial patterns of hyporheic exchange and biogeochemical cycling around cross‐vane restoration structures: Implications for stream restoration design

Gordon

Lautz

Daniluk

2013

Water Resources Research

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[1] Natural channel design restoration projects in streams often include the construction of cross-vanes, which are stone, dam-like structures that span the active channel. Vertical hyporheic exchange flux (HEF) and redox-sensitive solutes were measured in the streambed around four cross-vanes with different morphologies. Observed patterns of HEF and redox conditions are not dominated by a single, downstream-directed hyporheic flow cell beneath cross-vanes. Instead, spatial patterns of moderate (<0.4 m d À1 ) upwelling and downwelling are distributed in smaller cells around pool and riffle bed forms upstream and downstream of structures. Patterns of biogeochemical cycling are controlled by dissolved oxygen concentrations and resulting redox conditions, and are also oriented around secondary bed forms. Strong downwelling into the hyporheic zone (0.5-3.5 m d À1 ) was observed immediately upstream of structures, but was limited to an area 1-2 m from the cross-vane; these hyporheic flow paths likely rejoin the stream at the base of cross-vanes after residence times too short to alter nitrate concentrations or accumulate reaction products. Total hyporheic exchange volumes are $0.4% of stream discharge in restored reaches of 45-55 m. Results show that shallow hyporheic flow and associated biogeochemical cycling near cross-vanes is primarily controlled by secondary bed forms created or augmented by the cross-vane, rather than by the cross-vane itself. This study suggests that cross-vane restoration structures benefit the stream ecosystem by creating heterogeneous patches of varying HEF and redox conditions in the hyporheic zone, rather than by processing large amounts of nutrients to alter in-stream water chemistry.Citation: Gordon, R. P., L. K. Lautz, and T. L. Daniluk (2013), Spatial patterns of hyporheic exchange and biogeochemical cycling around cross-vane restoration structures: Implications for stream restoration design, Water Resour.

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“…Several endeavors have been made to describe the relationship between the intensity of K and the buffering capacity of soil K content. Evangelou et al (1994) reported that the high value of labile K indicates an increased release of K in the soil solution as a result of a greater pool of soil potassium. The high value of the potential buffering capacity of potassium (PBC k ) implies that the availability of K is good, while the low value of PBC k indicates that K fertilization is required.…”

mentioning

confidence: 99%

Evaluation of Potassium Quantity-Intensity in some Soils of El-Dakhla Oasis, New Valley, Egypt

2017

Alexandria Science Exchange Journal: An International Quarterly

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The current research was carried out in 2016 to evaluate potassium Quantity-Intensity parameters and the relation of these parameters to the characteristics of some agricultural soils of El-Dakhla Oasis, New Valley, Egypt. Six surface soil samples (0-30 cm) were collected from different sites in El-Dakhla Oasis. The values of equilibrium activity ratio of potassium (AR k o ) ranged between 0.0071 (soil 3) to 0.0320 (mol/L)

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New Developments and Perspectives on Soil Potassium Quantity/Intensity Relationships

Cited by 74 publications

References 109 publications

Potassium supplying capacity of some tropical alfisols in southwest Nigeria as measured by intensity, quantity and capacity factors

Potassium supplying capacity of some tropical alfisols in southwest Nigeria as measured by intensity, quantity and capacity factors

Spatial patterns of hyporheic exchange and biogeochemical cycling around cross‐vane restoration structures: Implications for stream restoration design

Evaluation of Potassium Quantity-Intensity in some Soils of El-Dakhla Oasis, New Valley, Egypt

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