scholarly journals Variation of pH Dependent Acidity and Total Potential Acidity as Influenced by Land Uses and Soil Depths in Lateritic Belt of West Bengal

Author(s):  
Jhutan Debnath ◽  
Prodipto Sow ◽  
Manik Chandra Kundu
2011 ◽  
Vol 23 (3) ◽  
pp. 545-558 ◽  
Author(s):  
V. C. Jha ◽  
S. Kapat

Degradation of lateritic environment as found in the south western and eastern Birbhum district can be considered as irresistible. Inherently poor physical and chemical status of existing lateritic soil profile and radical conversion of land uses as observed at cadastral level are the key factors of land degradation. Lateritic soilscapes are mostly affected by water erosion induced, vegetal and anthropogenic degradation attaining severe and very severe degradation status. Degraded lands in sample mouzas like Ballabhpur, Shyambati, Chawpahari Jungle, Bodakuri and Pachami account for 60.33%, 71.42%, 72.99%, 87.31% and 79.66% respectively out of their total lateritic exposures. In other words about 36.98%, 71.42%, 61.73%, 56.70% and 76.02% out of their total village areas and mostly non agricultural land use are affected by it. Four degraded villages get the higher priority for friendly landscape conservation actions.


2018 ◽  
Vol 10 (4) ◽  
pp. 370
Author(s):  
Victor Roberto Ribeiro Reis ◽  
Diana Signor Deon ◽  
Luciano Cavalcante Muniz ◽  
Uelson Serra Garcia ◽  
Ilka South de Lima Cantanhêde ◽  
...  

The sustainability of ecosystems is closely linked with the assessment of soil properties that estimate their quality. This work proposes to evaluate soil chemical attributes as a function of the implantation of a crop-livestock-forest integration system (ICLF) in the region of Mata dos Cocais in the state of Maranhão, Northeast Brazil. The four different land uses evaluated were native vegetation with babassu, capoeira vegetation, degraded pasture and area under ICLF system (with marandu grass, maize and eucalyptus consortium). The samples were collected up to one meter deep, comprising seven layers: 0.00-0.10, 0.10-0.20, 0.20-0.30, 0.30-0.40, 0.40-0.60, 0.60-0.80 and 0.80-1.0 m. The chemical attributes evaluated were pH, Ca, Mg, Al, P, K and Na, potential acidity, base sum, base saturation and soil cation exchange capacity (CEC). The levels of P, in the 0.00-0.10 m layer, were higher in the ICLF system than those of the native forest with babassu. The levels of K in the ICLF system and degraded pasture were higher than the other land uses up to a depth of 0.40 m, ranging from 0.92 cmolc dm-3 to 0.62 cmolc dm-3 and 1.04 cmolc dm-3 and 0.67 cmolc dm-3, respectively. Base saturation was higher in soils under ICLF system and degraded pasture than those observed in native forest and capoeira vegetation. There was an effect in chemical attributes of the soil such as a function of land use and, in general, the highest values were found in areas with degraded pasture and ICLF.


Soil Research ◽  
2002 ◽  
Vol 40 (3) ◽  
pp. 443 ◽  
Author(s):  
Nicholas J. Ward ◽  
Leigh A. Sullivan ◽  
Richard T. Bush ◽  
Chuxia Lin

Total sulfidic acidity (TSA) and total potential acidity (TPA) are derived from peroxide oxidation of acid sulfate soil materials (ASS), and are measures of the sulfidic acidity and the net acidity (net acidity = sulfidic acidity + actual acidity – acid neutralising capacity), respectively. The TSA and TPA of 4 ASS materials were determined using a variety of peroxide oxidation procedures and compared with the sulfidic acidity and net acidity derived from the use of an acid–base accounting model. TSA and TPA values both varied greatly with each peroxide oxidation method used, and both measures were found to substantially underestimate (i.e. by 23–85%) both sulfidic acidity (as determined from the chromium reducible sulfur content) and net acidity (as determined by acid–base accounting). A major cause of this underestimation of acidity was the retention of acidity through the precipitation of jarosite during peroxide oxidation. Substantial clay mineral dissolution appears to have occurred during peroxide oxidation of the ASS materials, as indicated by increased soluble aluminium. Such dissolution may contribute to the underestimation of both sulfidic and net acidity for the ASS materials using peroxide oxidation methods. The loss of acidity to the atmosphere was identified as a possible additional interference. This study shows the peroxide oxidation methods examined here are subject to substantial interferences, which caused large underestimations of acidity, and consequently, are unable to reliably provide accurate measurements of sulfidic and net acidity in ASS materials. pyritic sulfur, total potential acidity, total sulfidic acidity, net acidity, jarosite, acid budget, acid neutralising capacity.


1969 ◽  
Vol 21 (03) ◽  
pp. 573-579 ◽  
Author(s):  
P Fantl

SummaryTreatment of human and dog oxalated plasma with 0.2 to 1.0 × 10−1 M 2.3-dithiopropanol (BAL) or dithiothreitol (DTT) at 2–4° C for 30 min results in the reduction of the vitamin-K dependent clotting factors II, VII, IX and X to the respective-SH derivatives. The reaction is pH dependent. Under aerobic conditions the delayed one stage prothrombin time can be partly reversed. Under anaerobic conditions a gradual prolongation of the one stage prothrombin time occurs without reversal.In very diluted plasma treated with the dithiols, prothrombin can be converted into thrombin if serum as source of active factors VII and X is added. In contrast SH factors VII, IX and X are inactive in the specific tests. Reoxidation to active factors II, VII, IX and X takes place during adsorption and elution of the SH derivatives. The experiments have indicated that not only factor II but also factors VII, IX and X have active-S-S-centres.


Planta Medica ◽  
2007 ◽  
Vol 73 (09) ◽  
Author(s):  
M Gangopadhyay ◽  
R Bhattacharya ◽  
D Chakraborty ◽  
S Bhattacharya ◽  
A Mitra ◽  
...  

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