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Cation exchange capacity is a commonly used soil chemical property that describes the maximum quantity of cations a soil or substrate can hold while being exchangeable with the soil solution. Cation exchange capacity is often associated with a soil

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be neutralized and in the buffering capacity of moss peats. Two factors that may affect the neutralization requirement and buffering capacity of moss peat among batches are cation exchange capacity (CEC) and base saturation [fractional calcium (Ca 2

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Problems of inconsistent initial pH in peat moss-based substrates that are created using standard formulas for limestone additions, and pH drift from the target in those substrates may be due to variations in the CEC and BS of peat moss. This study was conducted to determine whether such variation exists. Sixty-four peat moss samples were obtained from several bogs across Alberta, Canada. Adsorbed cations on each peat moss sample were displaced with hydrochloric acid (HCl), and flushed out with three deionized water washes. The displacing/flushing solution was collected and later analyzed for concentration of bases (Ca, Mg, K, and Na) using atomic absorption spectrometry. After cations were removed, the peat moss exchange sites were saturated with barium acetate [Ba(OAc)2] to displace the H+, which were then collected by a second flushing with deionized water. This second displacing/flushing solution was titrated with measured amounts of NaOH to a phenolphthalein end point. Base saturation and CEC were calculated. There were significant variations in CEC (ranging from 108.12 to 162.25 cmol·kg-1) and BS (ranging from 13.52% to 63.97% of CEC) among the peat moss samples. Ca accounted for 78.08% of the BS. For a given peat moss, the higher the BS, the lower the neutralization requirement to achieve a target pH. Also, high CEC peat mosses may have greater buffering capacity than those with low CEC, which may result in less pH drift.

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Aluminum (Al) uptake by and root cation exchange capacity (CEC) of mycorrhizal (M) and nonmycorrhizal (NM) blueberry (Vaccinium corymbosum L.) plants were studied. Root CEC was higher in M plants than in NM plants, but total and root Al contents were higher in NM plants. Leaf Al content was higher in NM than in M plants after 1 and 5 hours of exposure. The aurintriboxylic acid stain for Al indicated the presence of Al in the M symbiont. Despite a larger root system and higher root CEC, regression analysis indicated roots of M plants absorbed less Al in the first 5 hours, suggesting that Al sequestration in the M symbiont is responsible for reduced total Al uptake. Differences in dry matter partitioning between M and NM plants were also observed.

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Abstract

Calcium adsorption on the root exchange sites of 4 vegetables as determined by the isotopic exchange method (Ca40–Ca45) was a function of its concentration in the external solution surrounding the roots. As the Ca concentration was increased over the range 0.2 me–8.0 me Ca/1, there was an increase in the Ca adsorbed on roots of sweet corn, cv. ‘Gold Rush’, garden bean cv. ‘Topcrop’, lettuce cv. ‘Bibb’ and cabbage. The Ca adsorption curve of all 4 vegetables showed a plateau between concentrations of 1 and 2 me Ca/1. Root CEC values obtained at Ca concentrations corresponding to this plateau compare closely with values reported by other methods, and are more representative of established CEC values than those reported where the Ca concentration in the external solution was 0.5 me Ca/1.

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Proper nutrient management in the root zone is important for maintaining a healthy turf ( Happ, 1995 ). Chemical properties such as pH and cation exchange capacity (CEC) of the root zone influence availability of essential nutrients and impact

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in this study include organic matter (SOM), active carbon or permanganate oxidizable carbon (POXC), aggregate stability, cation exchange capacity (CEC), bulk density, porosity, CO 2 -Burst, labile-amino nitrogen, pH, and total N. Materials and

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lamps from 0600 hr to 2000 hr daily. Cation exchange capacity, carbon-to-nitrogen ratio, particle size distribution, and bulk density. Cation exchange capacity, C:N ratio, particle size distribution, and BD were determined for five treatments: non

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, representing 44% to 71% of cations in soil solution on a charge basis; the soils averaged 34 mmolc·L −1 Ca, representing 57% of cation charges. Soil solution Ca was highly correlated with saturated paste Ca ( r 2 = 0.70) but not exchangeable Ca ( r 2 = 0

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retention ( Githinji, 2014 ), and cation exchange capacity (CEC) ( Marx et al., 1996 ; Reichert et al., 2016 ). Rapid drainage leads to nutrient leaching through sand-based root zones ( Bigelow et al., 2001 ; Mohamed et al., 2016 ; Petri and Petrovic

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