Acidification rates in the central wheatbelt of Western Australia. 2. On a sandy duplex soil

1994 ◽  
Vol 34 (8) ◽  
pp. 1165 ◽  
Author(s):  
PJ Dolling ◽  
WM Porter ◽  
IC Rowland

The rate and mechanisms of acidification were determined on a sandy duplex soil (depth of sand 30-45 cm) under a cereal-annual pasture rotation in Western Australia. We also evaluated the effect of rotation (intensity of cropping) on relative acidification of a sandy duplex soil. Rate of acidification was based on a linear regression analysis between soil pH and years since clearing. Sites were sampled to a depth of 50 cm in 10-cm increments and measurements included soil pH, pH buffering capacity, and bulk density. The effect of different rotations on the acidification rate was determined by soil sampling a rotation experiment which had been established for 25 years. Sampling and measurements were similar to the regression analysis. From regression, the rate of acidification for the profile was 0.15 kmol H+/ha.year, requiring 7.7 kg CaCO3 to neutralise. Most of the acidification could be accounted for by removal of alkaline products. Acidification was occurring to a depth of 30 cm, the acidification rate decreasing with depth. In the surface 20 cm the pH decline was 0.005-0.006 units/year. In the rotation experiment, the rate of acidification relative to continuous wheat without fertiliser nitrogen (N) ranged from 0.35 kmol H+/ha .year (17.5 kg CaCO3) for continuous wheat with fertiliser N to 0.92 kmol H+/ha. year (45.8 kg CaCO3) for continuous pasture. Between these rates was 1 year pasture-1 year cereal (0.41 kmol H+/ha. year, 20.5 kg CaCO3) and 2 years pasture-1 year cereal (0.82 kmol H+/ha . year, 41.2 kg CaCO3). Acidification was occurring to 60 cm depth in all rotations, mostly due to nitrate leaching, removal of alkaline products, and build-up of organic matter.

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

2019 ◽  
Vol 10 ◽  
pp. 1594-1610
Author(s):  
Todd Pirtle ◽  
Lee Rumble ◽  
Michael Klug ◽  
Forbes Walker ◽  
Song Cui ◽  
...  

Short-season forage radish (Raphanus sativus L. var. longipinnatus) has recently gained great popularity in Middle Tennessee and many parts of the world used as a high-quality vegetable crop for human consumption or a forage crop for winter grazing and cover cropping. In this study, we (i) estimated soil pH buffering capacity and microbial activity, (ii) quantified crop productivity influenced by different biochar amendment rates and N fertilizer management practices based on a factorial treatment design. Particularly, biochar was amended at rates of 0, 5, 20, and 40 Mg/ha; N fertilizer was applied at zero (N0), 122 kg/ha of urea (56 kg/ha of N; N1) and 4.8 Mg/ha of aged dairy cattle manure (56-60 kg/ha of N), providing a total of 12 treatments (four biochar rates × three fertilization practices). The combination of biochar and inorganic N fertilizer such as urea appeared to have positive impacts on the short-term biomass production, soil pH buffering capacity, and enhanced soil microbial activity for short-season forage radish production (P < 0.05). Future research is warranted to evaluate the use of biochar in field-based forage/vegetable studies in Tennessee.


2012 ◽  
Vol 76 (2) ◽  
pp. 694-699 ◽  
Author(s):  
D. E. Kissel ◽  
L. S. Sonon ◽  
M. L. Cabrera

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2223
Author(s):  
Prisca Divra Johan ◽  
Osumanu Haruna Ahmed ◽  
Latifah Omar ◽  
Nur Aainaa Hasbullah

Soil-available P for crop use is limited because of fixation reaction and loss of organic matter through erosion and surface runoff. These factors cause an imbalance between inputs and outputs of P nutrients in acid soils. Several approaches to improve P availability have been proposed, however, little is known about the effectiveness of amending humid mineral acid soils with charcoal and sago bark ash on P dynamics. Thus, pH buffering capacity and leaching studies were conducted to determine: (i) pH buffering capacity upon application of charcoal and sago bark ash and (ii) the influence of charcoal and sago bark ash on P leaching in acid soils. pH buffering capacity was calculated as the negative reciprocal of the slope of the linear regression (pH versus acid addition rate). A leaching study was carried out by spraying distilled water to each container with soil such that leachates through leaching were collected for analysis. The ascending order of the treatments based on their pH buffering capacity and regression coefficient (R2) were soil alone (0.25 mol H+ kg−1 sample), soil with charcoal (0.26 mol H+ kg−1 sample), soil with sago bark ash (0.28 mol H+ kg−1 sample), charcoal alone (0.29 mol H+ kg−1 sample), soil with charcoal and sago bark ash (0.29 mol H+ kg−1 sample), and sago bark ash alone (0.34 mol H+ kg−1 sample). Improvement in the soil pH buffering capacity was partly related to the inherent K, Ca, Mg, and Na contents of charcoal and sago bark ash. In the leaching study, it was noticed that as the rate of sago bark ash decreased, the pH of leachate decreased, suggesting that unlike charcoal the sago bark ash has significant impact on the alkalinity of leachate. Soil exchangeable acidity, Al3+, and H+ reduced significantly following co-application of charcoal and sago bark ash with ERP. This could be attributed to the neutralizing effects of sago bark ash and the high affinity of charcoal for Al and Fe ions. The amount of P leached from the soil with 100% charcoal was lower because charcoal has the ability to capture and hold P-rich water. The findings of this present study suggest that combined use of charcoal and sago bark ash have the potential to mitigate soil acidity and Al toxicity besides improving soil pH buffering capacity and minimizing P leaching. A field trial to consolidate the findings of this work is recommended.


2004 ◽  
Vol 68 (2) ◽  
pp. 662 ◽  
Author(s):  
A. R. Weaver ◽  
D. E. Kissel ◽  
F. Chen ◽  
L. T. West ◽  
W. Adkins ◽  
...  

2020 ◽  
pp. 6-12
Author(s):  
Tahsina Sharmin Hoque ◽  
Shafia Afrin ◽  
Israt Jahan ◽  
Md. Joinul Abedin Mian ◽  
Mohammad Anwar Hossain

Soil depth can significantly influence the availability of nutrients in soil. An experiment was conducted with seven soil samples from seven land use types to observe the effect of soil depth on soil properties under various land use systems. Soil pH, electrical conductivity (EC), organic matter, available phosphorus (P), available sulphur (S) and different forms of potassium (K) such as water soluble, exchangeable and non-exchangeable were determined from the soil samples collected from four soil depths (viz. 0-10, 10-20, 20-30 and 30-40 cm). Soil pH varied from 6.30-7.39 irrespective of depths and land uses and it increased with increasing soil depth. Electrical conductivity of the soils ranged from 42-310 µS cm-1 and organic matter status of most of the soils was very low to medium in level. Both EC and organic matter content decreased with the increase of soil depth. Available P concentration showed no specific changing trend with soil depth whereas available S concentration under different land use systems decreased with increasing soil depth. The concentrations of water soluble, exchangeable and non-exchangeable K in soils varied from 12.30-39.60, 20.90-53.16 and 163.30-684.30 mg kg-1, respectively and showed no specific changing pattern with soil depth. Water soluble K content was higher in rice growing fertilizer and manure-treated soil but higher exchangeable and non-exchangeable K contents were observed in banana growing soil. In rice growing soils, nutrient concentration is mostly higher in nitrogen (N), P and K + farm yard manure (FYM) - treated plots compared to rice growing control plots.


2018 ◽  
Vol 63 (01) ◽  
pp. 63-68
Author(s):  
Efka Zabokova Bilbilova ◽  
Ana Sotirovska Ivkovska ◽  
Olivera Sarakinova ◽  
Olga Kokoceva Ivanovska ◽  
Natasha Stavreva

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


Sign in / Sign up

Export Citation Format

Share Document