scholarly journals Calcium Carbonate Can Be Used to Manage Soilless Substrate pH for Blueberry Production

Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 74
Author(s):  
Michael Schreiber ◽  
Gerardo Nunez
Keyword(s):  
Biomass Accumulation ◽  
Low Ph ◽  
Buffering Capacity ◽  
Solution Ph ◽  
Ph Buffering ◽  
Substrate Amendment ◽  
Soilless Substrate ◽  
Southern Highbush ◽  
Substrate Ph ◽  
Ph Buffering Capacity

Blueberry (Vacciniumcorymbosum interspecific hybrids) production in soilless substrates is becoming increasingly popular. Soilless substrates have low pH buffering capacity. Blueberry plants preferentially take up ammonium, which acidifies the rhizosphere. Consequently, soilless substrates where blueberry plants are grown exhibit a tendency to get acidified over time. Agricultural lime (CaCO3) is commonly used to raise soil and substrate pH in other crops, but it is rarely used in blueberry cultivation. We hypothesized that substrate amendment with low rates of agricultural lime increases substrate pH buffering capacity and provides nutritional cations that can benefit blueberry plants. We tested this hypothesis in a greenhouse experiment with ‘Emerald’ southern highbush blueberry plants grown in rhizoboxes filled with a 3:1 mix of coconut coir and perlite. We found that substrate amendment with CaCO3 did not cause high pH stress. This amendment maintained substrate pH between 5.5 and 6.5 and provided Ca and Mg for plant uptake. When blueberry plants were grown in CaCO3-amended substrate and fertigated with low pH nutrient solution (pH 4.5), they exhibited greater biomass accumulation than plants grown in unamended substrates. These results suggest that low rates of CaCO3 could be useful for blueberry cultivation in soilless substrates.

scholarly journals Establishing Growing Substrate pH with Compost and Limestone and the Impact on pH Buffering Capacity

HortScience ◽  
2016 ◽  
Vol 51 (9) ◽  
pp. 1153-1158 ◽  
Author(s):  
Matthew D. Taylor ◽  
Rachel Kreis ◽  
Lidia Rejtö
Keyword(s):  
Factorial Design ◽  
Weight Ratio ◽  
Green Plant ◽  
Buffering Capacity ◽  
Ph Buffering ◽  
Initial Substrate ◽  
Initial Ph ◽  
The Impact ◽  
Substrate Ph ◽  
Ph Buffering Capacity

The pH of peatmoss generally ranges from 3.0 to 4.0 and limestone is typically added to raise pH to a suitable range. Compost is also used as a substrate component and typically has a high pH of 6.0 to 8.0. When using compost, lime rates must be reduced or eliminated. The two objectives of this study were to determine the resulting pH of substrates created with varying amounts of limestone and compost and assess the impact of the various amounts of limestone and compost on pH buffering capacity. Compost was created from a 1:1:1 weight ratio of a mixture of green plant material and restaurant food waste:horse manure:wood chips. The first experiment was a factorial design with five compost rates (0%, 10%, 20%, 30%, and 40% by volume), four limestone rates (0, 1.2, 2.4, and 3.6 g·L−1 substrate) with five replications. The experiment was conducted three times, each with a different batch of compost. With 0 lime, initial substrate pH increased from 4.5 to 6.7 as compost rate increased. This trend occurred at all other lime rates, which had pH ranges of 5.2–6.9, 5.6–7.0, and 6.1–7.1 for rates of 1.2, 2.4, and 3.6 g·L−1 substrate, respectively. Substrate pH increased significantly as either compost or lime rates increased. The second experiment was a factorial design with four compost rates by volume (0%, 10%, 20%, and 30%), the same four limestone rates as Expt. 1, and five replications. Each substrate treatment was titrated through incubations with six sulfuric acid rates (0, 0.1, 0.2, 0.4, or 0.7 mol of H+ per gram of dry substrate). Substrates with a similar initial pH had very similar buffering capacities regardless of the compost or limestone rate. These results indicate compost can be used to establish growing substrate pH similar to limestone, and this change will have little to no effect on pH buffering capacity.

Enhanced solubilization of rock phosphate by Penicillium bilaiae in pH-buffered solution culture

2006 ◽  
Vol 52 (11) ◽  
pp. 1121-1129 ◽  
Author(s):  
M Takeda ◽  
J D Knight
Keyword(s):  
Rock Phosphate ◽  
Fungal Growth ◽  
Solution Culture ◽  
Buffering Capacity ◽  
Solution Ph ◽  
Ph Buffering ◽  
Enhanced Production ◽  
Penicillium Bilaiae ◽  
Ph Buffering Capacity ◽  
Oxalic Acids

Little is known about how pH-buffering capacity affects phosphorus (P) solubilization by Penicillium bilaiae. This study compared solubilization of rock phosphate (RP) by P. bilaiae in nonbuffered (pH 5.0) and buffered (pH 7.0) media. Fungal growth reached the stationary phase around day 12 and was slightly enhanced in the buffered medium. The fungus reduced solution pH from 5.0 to 4.1 in the nonbuffered medium and from 7.0 to 4.9 in the buffered medium by day 12. Phosphorus concentrations increased after day 9 more in the buffered than in the nonbuffered media (53 and 5 mg P·L–1, respectively, on day 12). On day 12, higher concentrations of citric and oxalic acids were detected in the buffered (2.0 and 1.2 g·L–1, respectively) than nonbuffered media (0.5 and 0.04 g·L–1, respectively). Solubilization of RP was simulated without P. bilaiae in solutions equivalent to the nonbuffered and buffered cultures of P. bilaiae grown with RP. After a 24 h incubation, the P concentrations were of similar magnitudes to those observed in the P. bilaiae culture (18 and 47 mg P·L–1, respectively, in the nonbuffered and buffered media). Under increased pH-buffering conditions, the enhanced production of citric and oxalic acids led to significant RP solubilization.Key words: phosphorus solubilization, pH buffering, Penicillium bilaiae, citric acid, oxalic acid.

Mapping Soil pH Buffering Capacity of Selected Fields in the Coastal Plain

2004 ◽  
Vol 68 (2) ◽  
pp. 662-668 ◽  
Author(s):  
A. R. Weaver ◽  
D. E. Kissel ◽  
F. Chen ◽  
L. T. West ◽  
W. Adkins ◽  
...  
Keyword(s):  
Soil Ph ◽  
Coastal Plain ◽  
Buffering Capacity ◽  
Ph Buffering ◽  
Ph Buffering Capacity

scholarly journals Correlation between pH, buffering capacity, calcium and dental caries in schoolchildren

2018 ◽  
Vol 63 (01) ◽  
pp. 63-68
Author(s):  
Efka Zabokova Bilbilova ◽  
Ana Sotirovska Ivkovska ◽  
Olivera Sarakinova ◽  
Olga Kokoceva Ivanovska ◽  
Natasha Stavreva
Keyword(s):  
Dental Caries ◽  
Free Group ◽  
Buffer Capacity ◽  
Saliva Sample ◽  
Buffering Capacity ◽  
Active Group ◽  
Ph Buffering ◽  
Ph Values ◽  
Salivary Ph ◽  
Ph Buffering Capacity

The aim of this study was to determine salivary pH, buffering capacity and calcium levels in caries-free and caries-active children. We examined 80 children of both genders, 15 years of age. Subjects were divided into four groups as follows: caries-free females, caries-active females, caries-free males, caries-active males; each group consisted of 20 subjects. The unstimulated saliva sample was collected by the spitting method and then pH, buffering capacity and calcium in saliva was measured. The results showed that mean level of buffering capacity of saliva was decreased significantly in the caries-active group as compared to caries-free group. The obtained data showed that the mean levels of pH and calcium were decreased in the caries-active group as compared to the caries-free group, but the difference was not statistically significant. The saliva with its constituents plays an important role in maintaining oral and especially dental health. Salivary pH values were found to be higher in the caries-free group. In our study, there was no significant correlation of pH values and caries activity with gender. Buffer capacity values were significantly lower in the caries-active group than in the caries-free group. There were significant differences when the groups were compared in the caries-active group where buffer capacity values were higher in boys than in girls. Calcium content of saliva was higher in the caries-free group. The results obtained in this study related to the values of the pH, buffering capacity and calcium in saliva, may serve as parameters for determining the caries risk patients, and accordingly to plan and carry appropriate caries preventive measures. Keywords: saliva, dental caries, pH, buffer capacity, calcium

scholarly journals Effects of Refining Parameters on the Properties of Oil Palm Frond (OPF) Fiber for Medium Density Fibreboard (MDF)

2021 ◽  
Vol 87 (3) ◽  
pp. 64-77
Author(s):  
Zawawi Ibrahim ◽  
Aisyah Humaira Alias ◽  
Ridzuan Ramli ◽  
Noorshamsiana Abdul Wahab ◽  
Mansur Ahmad ◽  
...  
Keyword(s):  
Oil Palm ◽  
Bonding Strength ◽  
Medium Density Fiberboard ◽  
Steam Pressure ◽  
Buffering Capacity ◽  
Medium Density ◽  
Ph Buffering ◽  
Oil Palm Frond ◽  
Palm Frond ◽  
Ph Buffering Capacity

Studies on the manufacture of medium density fiberboard (MDF) from oil palm frond (OPF) fibre were conducted to provide a sustainable and feasible source of lignocellulosic materials. The quality and properties of the fibre are very important as it dictates the final MDF properties. The properties of fibre like fibre pH, buffering capacity, and morphology can influence most of the MDF performances. Refining condition is one of the most important factors which determine the properties of the refined fibre. In this study, the effects of different refining pressures and temperatures on OPF fibre were evaluated. The refining of OPF fibre was observed at four levels of refining parameters; which were categorized as low (2 bar at 130 °C), medium (4 bar at 150 °C), high (6 bar at 170 °C), and severe (8 bar at 190 °C). The refining heating time of 5 minutes was employed. The pH, buffering capacity, morphology, and the surface of the fibres were evaluated. The refined fibres were used to manufacture fibreboard panels at a target density of 720 kg/m3 and 12% urea formaldehyde (UF) resin. The panel's physical (thickness swelling) and mechanical properties (bending and internal bonding strength) were then evaluated according to European Standard (EN 622-5, 2006). The results indicated that refining conditions affected the properties of the fibres and final boards. High steam pressure and temperature-induced pH changes in OPF fibres, leading to more acidic fibres and greater acid buffering capacity. The fibre separation was more adequate at this level and produced fibre with a smooth surface. Based on the test results for fibreboard properties, high steam pressure and temperature produced better dimensional stability of panels and bending and bonding strength. However, at the highest refining condition (severe level), the board performances began to deteriorate. The best performances of the samples were found for the panels made under refining conditions of 6 bar at 170 °C.

Exercise alters the regulation of myocardial Na+/H+ exchanger-1 activity

2013 ◽  
Vol 305 (10) ◽  
pp. R1182-R1189 ◽  
Author(s):  
Bryan J. Feger ◽  
Joseph W. Starnes
Keyword(s):  
Intracellular Ph ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Weight Ratio ◽  
Buffering Capacity ◽  
Strenuous Exercise ◽  
Sprague Dawley ◽  
Ph Buffering ◽  
Nhe1 Activity ◽  
Ph Buffering Capacity

The myocardial Na+/H+ exchanger-1 (NHE1) plays a major role in regulation of intracellular pH, and its upregulation has been implicated in increased ischemia-reperfusion injury and other pathologies. Hydrogen peroxide (H2O2) increases NHE1 activity acutely via ERK1/2 signaling. Chronic strenuous exercise upregulates NHE1 in skeletal muscle, but we hypothesize this will not occur in the heart, because exercise creates a cardioprotective phenotype. NHE1 activity and its regulation by H2O2 were examined at physiological pH using isolated cardiomyocytes from female Sprague-Dawley rats exercised on a treadmill for 5 wk (E; n = 11). Compared with sedentary (S; n = 15), E displayed increases ( P < 0.05) in heart-to-body weight ratio (6.8%) and plantaris mitochondria content (89%). NHE1 activity (acid efflux rate following an acid load) was 209% greater in E (0.65 ± 0.12 vs. 2.01 ± 0.29 fmol/min). The difference was attributed primarily to greater cell volume (22.2 ± 0.6 vs. 34.3 ± 1.1 pl) and intracellular pH-buffering capacity (33.94 ± 1.59 vs. 65.82 ± 5.20 mM/pH unit) of E myocytes. H2O2 stimulation (100 μM) raised NHE1 activity significantly less in E (45%) than S (167%); however, activity remained 185% greater in E. ERK1/2 inhibition abrogated the increases. H2O2-stimulated ERK1/2 phosphorylation levels normalized to total ERK1/2 were similar between groups. Content of NHE1 and activities of H2O2 scavengers were also similar. We observed that intracellular pH-buffering capacity differences between groups became progressively less with declining pH, which may be an exercise-induced cardioprotective adaptation to lower NHE1 activity during certain pathological situations. We conclude that strenuous endurance exercise increases myocardial NHE1 activity at physiological pH, which would likely enhance cardiac performance under physiological conditions.

Chromate adsorption and pH buffering capacity of zinc hydroxy salts

2010 ◽  
Vol 48 (3) ◽  
pp. 455-459 ◽  
Author(s):  
Teruhisa Hongo ◽  
Takeshi Iemura ◽  
Shigeo Satokawa ◽  
Atsushi Yamazaki
Keyword(s):  
Buffering Capacity ◽  
Ph Buffering ◽  
Ph Buffering Capacity
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