Chemical attributes of some Queensland acid aoils. I. Solid and solution phase compositions

Soil Research ◽  
1989 ◽  
Vol 27 (2) ◽  
pp. 333 ◽  
Author(s):  
RC Bruce ◽  
LA Warrell ◽  
LC Bell ◽  
DG Edwards

Samples from surface and subsoil horizons of 91 acid soils in Queensland were analysed for pH, EC, Cl, exchangeable cations and organic C. Generally low values for EC, Cl, exchangeable Na and exchangeable K were found in surface soils and subsoils. Higher values of organic C, exchangeable Ca and pH occurred more frequently in surface soils, while exchangeable A1 and exchangeable Mg were generally higher in subsoils. A correlation matrix gave significant, but not strong, linear correlations between soil attributes associated with soil acidity (pH and Ca, Mg and Al saturations). Soil solutions were extracted from surface and subsoil horizons of 48 of these acid soils and analysed for pH, EC, Na, K, Ca, Mg, SO4 and monomeric Al. Ionic strengths and activities of monomeric Al species were calculated. Soil solution pH tended to be lower in subsoils than in surface soils, but very few values were <4.5. Ionic strengths were mostly <8 mM, with mean values of 5.3 mM for surface soils and 2.4 mM for subsoils. Subsoils had lower mean concentrations of Ca, Mg and K, and similar concentrations of Na, compared with surface soils. In both groups, molar concentrations followed the order Na > K ~ Mg > Ca. Mean values for activities of AlOH2+, Al(OH)2+, Al(OH)3 and AlSO4+ in surface soils exceeded those for subsoils, but activities of Al3+ were similar. Higher activities of Al species in surface soils resulted from higher monomeric Al concentrations, but it was concluded that the analytical method overestimated monomeric Al in surface soils, probably by including some of the soluble organic Al complexes present. The best correlation between pH and Al species was with Al3+ , particularly in subsoils (r2 = 0.913). Activity of Al3+ in subsoils was correlated with ionic strength (r2 = 0.666) when both were expressed on a logarithmic scale.

1988 ◽  
Vol 39 (3) ◽  
pp. 319 ◽  
Author(s):  
RC Bruce ◽  
LA Warrell ◽  
DG Edwards ◽  
LC Bell

In the course of three experiments, soybean (Glycerine max (L.) Merr.) cv. Forrest was grown in 21 soils (four surface soils and 17 subsoils) amended with liming materials (CaCO3 and Mg CO3) and soluble Ca salts (CaSO4.2H20 and CaCl2.2H2O). In most soils, the soluble salts increased concentrations and activities of Al species in solution to levels that restricted root growth, and MgCO3, induced a Ca limitation to root growth. Root lengths after three days were related to so11 and soil solution attributes.Suitable diagnostic indices for the prediction of Ca limitations to root growth were either Ca saturation of the effective cation exchange capacity or Ca activity ratio of the soil solution, which was defined as the ratio of the activity of Ca to the sum of the activities of Ca, Mg, Na, and K. Values corresponding to 90% relative root length (RRL) of soybean were 0.05 for the Ca activity ratio and 11% for Ca saturation. Calcium activity and Ca concentration in the soil solution and exchangeable Ca were less useful for this purpose.Soil Al saturation was not a good predictor of Al toxicity, but soil solution measurements were. The activities of Al3+ and AlOH2+ gave the best associations with RRL, and values corresponding to 90% RRL were 4 8M and 0.5 8M respectively. The results suggested that Al(OH)3� , Al(OH)2+, and AlSO4+, were not toxic species. Soil solution pH and soil pH measured in water were more sensitive indicators of root growth than soil pH measured in 0.01 M CaCl2.Using a Ca activity ratio of 0.05 and an Al3+ activity of 4 8M as diagnostic indices, none of the 20 soils in two experiments were toxic in Al, while 13 (all subsoils) were deficient in Ca. Thus the first limitation on root growth was Ca deficiency and not Al toxicity, in spite of high Al saturations and relatively low pH in these soils. However, Al toxicity could be induced by increasing the ionic strengths of soil solutions.


1962 ◽  
Vol 34 (1) ◽  
pp. 107-114
Author(s):  
Armi Kaila

The ammonium fixing capacity of Finnish soils was studied by analysing a material of 139 samples from surface soils and 127 samples of deeper layers collected mainly from cultivated soils from various parts of the country. The pH-values of these samples measured in 0.02 N CaCl2-suspension ranged from 3.3 to 7.5, the content of organic C from 0 to 10.1 per cent, and the content of clay (< 2 μ) from 0 to 96 per cent. The ammonium fixing capacity was determined under moist conditions by treating the samples for 24 hours with N NH4CI solution corresponding to 1000 m.e. of NH4-N per 100 g of soil, and removing the easily exchangeable ions by washing with CaCl2 -solutions. The difference in the nitrogen content of treated and untreated samples determined by digesting in concentrated sulfuric acid, was taken to indicate the amount fixed under these conditions. The results varied from 0 to 4.0 m.e./100 g of soil in the surface samples, and from 0 to 15.9 m.e./100 g of the soils from the deeper layers. The corresponding mean values were 1.0 and 3.8 m.e. per 100 g of soil, respectively. The association of the ammonium fixing capacity (1) with the clay content (2), pH (3), and the content of organic C (4) of the samples could be characterized by the following partial linear correlation coefficients; r12;34 = 0.472*** r13;24 = 0.177 r14;23 = –0.313** The total linear correlation coefficient between the ammonium fixing capacity and the fixation of potassium under moist conditions (2.5 m.e. of K added to 100 g of soil) was r = 0.829***. No correlation existed between the ammonium fixing capacity and the content of exchangeable potassium in these samples. Some of the results point to the possibility that in certain soils the coarser fractions, from 2 to 6 μ, or even from 6 to 20 μ, may play an important role in the fixing of ammonium in difficultly exchangeable form. In spite of the fact that under laboratory conditions the ammonium fixing capacity of Finnish soils may be fairly high, even in the surface soils, the conclusion was drawn that usually under the field conditions, the fixation of ammonium ions in difficultly exchangeable form might not reduce the effect of ammonium nitrogen fertilizers to any marked degree.


Soil Research ◽  
1996 ◽  
Vol 34 (5) ◽  
pp. 735 ◽  
Author(s):  
E Diatloff ◽  
CJ Asher ◽  
FW Smith

Total, exchangeable, and soil solution concentrations were measured for 15 rare earth elements (REEs) in 9 soils from Queensland and New South Wales. In a further 10 acid soils, effects of amendment with CaCO3 or CaSO4 . 2H2O were measured on the concentrations of REEs in soil solution. The total concentration of the REEs in soil solutions from unamended soils ranged from below the detection limit (0.007 µM) to 0.64 µM. Lanthanum (La) and cerium (Ce) were the REEs present in the greatest concentrations, the highest concentrations measured in the diverse suite of soils being 0.13 µM La and 0.51 µM Ce. Rare earth elements with higher atomic numbers were present in very low concentrations. Exchangeable REEs accounted for 0.07 to 12.6% of the total REEs measured in the soils. Addition of CaCO3 increased soil solution pH and decreased REE concentrations in soil solution, whilst CaSO4 . 2H2O decreased soil solution pH and increased the concentrations of REEs in soil solution. Solubility calculations suggest that CePO4 may be the phase controlling the concentration of Ce in soil solution.


1997 ◽  
Vol 35 (5) ◽  
pp. 1-10 ◽  
Author(s):  
K. R. Reddy ◽  
E. M. D'Angelo

Wetlands support several aerobic and anaerobic biogeochemical processes that regulate removal/retention of pollutants, which has encouraged the intentional use of wetlands for pollutant abatement. The purpose of this paper is to present a brief review of key processes regulating pollutant removal and identify potential indicators that can be measured to evaluate treatment efficiency. Carbon and toxic organic compound removal efficiency can be determined by measuring soil or water oxygen demand, microbial biomass, soil Eh and pH. Similarly, nitrate removal can be predicted by dissolved organic C and microbial biomass. Phosphorus retention can be described by the availability of reactive Fe and Al in acid soils and Ca and Mg in alkaline soils. Relationships between soil processes and indicators are useful tools to transfer mechanistic information between diverse types of wetland treatment systems.


2011 ◽  
Vol 35 (4) ◽  
pp. 1100-1111 ◽  
Author(s):  
Guilherme Resende Corrêa ◽  
Carlos Ernesto G.R Schaefer ◽  
Vander de Freitas Melo ◽  
Kleberson Worslley de Souza ◽  
João Carlos Ker ◽  
...  

In prehistoric times, innumerous shell middens, called "sambaquis", consisting mainly of remains of marine organisms, were built along the Brazilian coast. Although the scientific community took interest in these anthropic formations, especially since the nineteenth century, their pedological context is still poorly understood. The purpose of this study was to characterize and identify the physical and chemical changes induced by soil-forming processes, as well as to compare the morphology of shell midden soils with other, already described, anthropogenic soils of Brazil. Four soil profiles developed from shell middens in the Região dos Lagos - RJ were morphologically described and the physical and chemical properties determined. The chemical analysis showed that Ca, Mn, Mg, and particularly P and Zn are indicators of anthropic horizons of midden soils, as in the Amazon Dark Earths (Terras Pretas de Índio). After the deposition of P-rich material, P reaction and leaching can mask or disturb the evidence of in situ man-made strata, but mineralogical and chemical studies of phosphate forms can elucidate the apparent complexity. Lower phosphate-rich strata without direct anthropic inputs indicate P leaching and precipitation in secondary forms. The total and bioavailable contents of Ca, Mg, Zn, Mn, Cu, P, and organic C of midden soils were much higher than of regional soils without influence of ancient human settlements, demonstrating that the high fertility persisted for long periods, at some sites for more than 4000 years. The physical analysis showed that wind-blown sand contributed significantly to increase the sand fraction in the analyzed soils (texture classes sand, sandy loam and sandy clay loam) and that the aeolian sand accumulation occurred simultaneously with the midden formation.


1973 ◽  
Vol 45 (3) ◽  
pp. 254-261
Author(s):  
Armi Kaila

210 samples of mineral soils from the southern half of Finland with mainly an acid precambrian bedrock, were analysed for the total contents of Ca, Mg and K, and for the portion of these nutrients which could be exchanged by N NH4OAc (pH 7), dissolved by 0.1 N HCI at room temperature, or released by N HCI at 50° C. The total content of Ca was lowest in samples of heavy clay, 0.78±0.14 % in the surface soils and 0.92±0.10 % in the deeper layers. The mean content in the groups of other soils was at least about 1.1 %. The total content of Mg increased with an increase in the clay content (r = 0.81***). It ranged from 0.6±0.1 % in the sand and fine sand samples to 1.53±0.19 % in the heavy clay soils of the surface layers and to 1.89±0.12 % in those of the deeper layers. Also in the groups of loam and silt soils and of the coarser clay soils, respectively, the Mg content was in the deeper layers higher than in the surface soils. The total content of K also increased with the clay content (r=0.73***) from 1.7±0.1 % in the sand and fine sand soils to 2.74±0.21 % in the heavy clay soils of the surface layers and to 3.10±0.07 % in those of the deeper layers. The portion of exchangeable Ca was relatively high: in the groups of surface soils from more than one tenth to one third of the total amount. The corresponding average amounts released by even the more drastic treatment with acid were not markedly higher. Only a few per cents of total Mg were exchangeable and slightly higher amounts were dissolved by 0.1 N HCI, whereas the treatment with N HCI at 50° C released about half of the total Mg. Exchangeable K and K dissolved by 0,1 N HCI did not exceed 1 % of the total K, except slightly in the heavy clay soils; the average amounts released by N HCI ranged from 5 to 18 % of the total K. The plant availability of these nutrients was discussed.


2015 ◽  
Vol 6 (3) ◽  
pp. 263 ◽  
Author(s):  
Milena Barcellos ◽  
Antonio Carlos Vargas Motta ◽  
Volnei Pauletti ◽  
José Carlos Peixoto Modesto Da Silva ◽  
Julierme Zimmer Barbosa

Organic fertilization in no-tillage system (NTS) has been used in regions milk production, in an order to provide nutrients for crops and provide a destination for high production of animal waste. The aim of this study was to evaluate the chemical attributes of an Oxisol, a function of organic fertilization with liquid manure from dairy cattle (LMDC) and mineral fertilizers. The experiment was conducted under NTS with crop rotation including legumes and grasses. The treatments were distributed in three randomized blocks with factorial arrangement, using three levels of mineral fertilizer (0, 50 and 100 % of the dose recommended for the crops) and four levels of organic fertilizer (0, 30, 60 and 90 m3 ha-1year-1). After six years of fertilizer management of crops, soil was collected from five depths (0-0.05, 0.05-0.10, 0.10-0.30, 0.30-0.50 e 0.50-0.80 m). The samples were determined the chemical pH, H++Al3+, Al3+, Ca2+, Mg2+, K+,electrical conductivity (EC), bases saturation (V), Ca2+/Mg2+ ratio, total organic C (TOC), B, Cl, Fe, Cu, Zn and Mn. The mineral fertilizers acidify the soil, raised the K+, P and EC and, changed the Zn and Cu contents. The organic fertilization with LMDC was a source of nutrients (Ca 2+, Mg2+, K+, P, Zn and Cu), raised the TOC and the EC, and kept the soil acidity attributes (pH, H++ Al3+ and V).


Soil Research ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 343 ◽  
Author(s):  
J Maggs ◽  
B Hewett

Some long term effects of (a) converting rainforest to grassland, and (b) rainforest regeneration on cleared land were investigated by comparing chemical properties of mineral soil (0-10 cm depth) from beneath primary rainforest, derived grassland and old secondary rainforest. Grasslands and secondary rainforest. were on land cleared at least 50 years ago. The study was undertaken on the Atherton Tableland in north east Queensland using soils formed on basalt, granite and metamorphic rocks. Organic C, kjeldahl N and labile N were 15-50% lower (P < 0.05) beneath grassland than primary rainforest for all soils, and were higher beneath secondary rainforest than grassland. Exchangeable Ca varied in a similar way in basaltic soils but did not differ between vegetation types in the other soils. Extractable Al was lower under grassland than either forest type for soils formed on granite and metamorphic rock. Total and organic P concentrations did not differ between primary forest and grassland, but were lowest under secondary rainforest for soils on metamorphic rock.


1976 ◽  
Vol 56 (3) ◽  
pp. 129-138 ◽  
Author(s):  
A. J. MACLEAN

The Cd concentration in 10 plant species grown in a neutral surface soil (0.65 ppm Cd) varied from 0.18 ppm in potato tubers to 0.99 ppm in soybean roots on a dry matter basis. Addition of 5 ppm Cd increased the concentrations in the plants markedly and they were particularly high in lettuce (10.36 ppm) and tobacco leaves (11.57 ppm). Cd concentrations tended to be lower in the edible portion (seed, fruit, tubers) than in other plant parts. Added Cd affected yields in only a few instances. But in another experiment, Cd added at a rate of 5 ppm to five soils decreased the yield of lettuce in most instances. In a comparison of results for two similarly managed sandy loam soils, nearly neutral in reaction but differing in organic matter content (2.17 vs. 15.95% organic C), the concentration of Cd was lower in lettuce grown in the soil with the higher amount of organic matter. The Cd content of the lettuce was reduced by liming some of the acid soils. Addition of Cd increased the concentration of Zn in the plants appreciably, but added Zn did not affect Cd uptake. In an incubation experiment comprising five soils, DTPA (diethylenetriamine-pentaacetic acid) extractable Cd decreased with liming of three Cd-treated acid soil samples. In comparisons of two sandy loam soils and of surface and subsoil layers of a sand, extractable Cd increased with higher amounts of soil organic matter.


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