Chemical attributes of some Queensland acid aoils. II. Relationships between soil and soil solution phase compositions

Soil Research ◽  
1989 ◽  
Vol 27 (2) ◽  
pp. 353 ◽  
Author(s):  
RC Bruce ◽  
LC Bell ◽  
DG Edwards ◽  
LA Warrell

Relationships were sought between soil and soil solution attributes by using the data of Bruce et al. (Part I). There was a strong linear relationship between EC of soil solutions and EC of 1:5 soil : water extracts (r2 = 0.904). In subsoils, the activity of Al3 + in soil solution was dependent on soil solution ionic strength and soil Al saturation, and was described by the following multiple regression equation: loge(Al3+) = -6.97 + 1.96logeIss + 0.0777Alsat.%

Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 151 ◽  
Author(s):  
DC Edmeades ◽  
DM Wheeler ◽  
OE Clinton

In preliminary experiments a centrifuge method for extracting soil solutions was examined. Neither the time nor speed of centrifuging had any effect on the concentrations of cations in soil solution. The concentration of cations increased with decreasing soil moisture content, and NO3, Ca, Mg, and Na concentrations increased with increasing time of storage of freshly collected moist soils. It was concluded that to obtain soil solutions, which accurately reflect the soil solution composition and ionic strength (I) in situ, requires that soil samples are extracted immediately (<24 h) following sampling from the field. Prior equilibration of soil samples, to adjust soil moisture contents, is therefore not valid. The effect of time of sampling and soil type, and the effects of fertilizer and lime applications, on soil solution composition and ionic strength, were measured on freshly collected field moist topsoils. Concentrations of Ca, Mg, K, Na, NH, and NO, were lowest in the winter and highest in the summer. Consequently, there was a marked seasonal variation in ionic strength which ranged from 0.003 to 0.016 mol L-1 (mean, 0.005 s.d. 0.003) over time and soil type. Withholding fertilizer (P, K, S, Ca) for two years had only a minor effect on ionic composition and strength, and liming increased solution Ca, Mg and HCO3, but decreased Al, resulting in a twofold increase in ionic strength. These results suggest that the ionic strength of temperate grassland topsoils in New Zealand lie within the range 0.003-0.016 and are typically 0.005.


Soil Research ◽  
1980 ◽  
Vol 18 (1) ◽  
pp. 13 ◽  
Author(s):  
R Sands ◽  
CPP Reid

Various techniques for measuring the osmotic potential of water in sand and loam at a range of soil water contents were examined. Results were inconsistent and variable when osmotic potential was derived by subtracting matric potential from total potential. Osmotic potential measurements on soil solution extruded at pressure through membranes were also unsatisfactory, probably due to salt sieving in the soil and/or at the membrane. Determining osmotic potential by linear dilution of an extract of 0.5 g g-1 soil solution can be criticized on several grounds, though the results presented for these soils seemed reasonable. The measurement of osmotic potential with in situ salinity sensors worked well in the loam but not in the sand. Measurements of the osmotic potential of displaced soil solutions were satisfactory for both soils. We concluded that the displacement technique was the most suitable for calibrating soil osmotic potential against soil water content, because it was simple, inexpensive in materials and time, and probably the least subject to error. The osmotic potential of soil dried by evaporation alone through a range of water contents was the same as that of soil dried by transpiration via lupins at two transpiration rates and via radiata pine. We concluded that the osmotic potential of the bulk soil in closed pots was independent of the activity of plants over the time scale of these experiments.


Soil Research ◽  
1978 ◽  
Vol 16 (1) ◽  
pp. 67 ◽  
Author(s):  
GP Gillman ◽  
LC Bell

Solutions obtained from six soils in tropical North Queensland after incubation at a moisture tension of 0.1 bar were analysed to obtain data on their ionic strengths. Soil extracts, at soil: solution ratios of 1:1, 1:2.5, 1:5, and 1:10 were also examined. Determinations on the aqueous phase included electrical conductivity, pH, ammonium, calcium, magnesium, potassium, sodium, bicarbonate, chloride, sulphate, and nitrate. Ionic concentrations of the soil solutions were found to be low when compared with many of the values reported in the literature. The upper limit for the ionic strength was about 0.005. Ionic strength was well correlated with the electrolytic conductivity of the soil solution itself, and also of the soil extracts. Relationships found between the soil solution and soil extracts in respect of total cation (and anion) content and also cation ratios, allow predictions about the soil solution to be made from soil extract data. Consideration of the ionic ratio of calcium to total cations in these soils suggests that the soils may have suboptimal levels of calcium for the growth of many plant species.


Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 151
Author(s):  
DC Edmeades ◽  
DM Wheeler ◽  
OE Clinton

In preliminary experiments a centrifuge method for extracting soil solutions was examined. Neither the time nor speed of centrifuging had any effect on the concentrations of cations in soil solution. The concentration of cations increased with decreasing soil moisture content, and NO3, Ca, Mg, and Na concentrations increased with increasing time of storage of freshly collected moist soils. It was concluded that to obtain soil solutions, which accurately reflect the soil solution composition and ionic strength (I) in situ, requires that soil samples are extracted immediately (<24 h) following sampling from the field. Prior equilibration of soil samples, to adjust soil moisture contents, is therefore not valid. The effect of time of sampling and soil type, and the effects of fertilizer and lime applications, on soil solution composition and ionic strength, were measured on freshly collected field moist topsoils. Concentrations of Ca, Mg, K, Na, NH, and NO, were lowest in the winter and highest in the summer. Consequently, there was a marked seasonal variation in ionic strength which ranged from 0.003 to 0.016 mol L-1 (mean, 0.005 s.d. 0.003) over time and soil type. Withholding fertilizer (P, K, S, Ca) for two years had only a minor effect on ionic composition and strength, and liming increased solution Ca, Mg and HCO3, but decreased Al, resulting in a twofold increase in ionic strength. These results suggest that the ionic strength of temperate grassland topsoils in New Zealand lie within the range 0.003-0.016 and are typically 0.005.


2017 ◽  
pp. 114-127
Author(s):  
N. A. Muromtsev ◽  
K. B. Anisimov ◽  
N. A. Semenov ◽  
V. V. Gribov

The dynamics of the soil water potential and soil temperature at different depths during the year was studied. As the object of the investigation we took soddy-podzolic clay loamy weakly gleyed soils of Zelenogradskiy base of Soil Science Institute. The data of soil water and temperature were derived from the automated meteorologic station “VantagePro2”. In conditions of the sustainable state of the other components of the environment, we discovered sharp spasmodic increase of the soil water potential at the passing of temperature values to the range below zero, i.e., in conditions of the phase overpass of the soil solution. All of the types of soil water potential changes (slow and rapid, significant and insignificant) occur due to the changes (decrease or increase) of the water content and soil temperature. For the first time in our country the thermohydrophysical phenomenon of (thermodynamic process) of sharp (at 5-6 times) and rapid (practically immediate) increase of the water potential after the overpass of the temperature over zero from the area of positive values to the negative values is discovered and described. The knowledge of specificities of the dynamics of soil water potential due to the temperature will allow us to plan the terms and norms of watering.


2019 ◽  
Author(s):  
Daniel A. Petrash ◽  
Frantisek Buzek ◽  
Martin Novak ◽  
Bohuslava Cejkova ◽  
Pavel Kram ◽  
...  

Abstract. In order to interpret spatial patterns of soil nutrient partitioning and compare these with runoff in a temperate forest with a history of acidification-related spruce die-back, the chemistry of mineral soil solutions were collected by suction lysimeters and evaluated relative to concurrent loads of anions and cations in precipitation. Lysimeters nest were installed in the 33-ha U dvou loucek (UDL) mountain catchment at different topographic positions (hilltops, slopes and valley). Following equilibration, monthly soil solution samples were collected over a 2-year period. In the vicinity of each lysimeter nest, soil pits were excavated for constraining soil chemistry. Soil solutions were analyzed for SO42−, NO3−, NH4+, Na+, K+, Ca2+, Mg2+, and total dissolved Al concentrations and organic matter (DOC), and pH. For a P release estimation, ammonium oxalate extraction of soil samples was performed. Comparison of soil water data with other previously acidified monitored European sites indicated that environmentally relevant chemical species at UDL had concentrations similar to median concentrations observed in sites with similar bedrock lithology and vegetation cover. Cation exchange capacity (CEC ≤ 58 meq kg−1) and base saturation (BS ≤ 13 %), however, were significantly lower at UDL, documenting incomplete recovery from acidification. Spatial trends and seasonality in soil water chemistry support belowground inputs from mineral-stabilized legacy pollutants. Overall, the soil-solution data suggest the system is out of balance chemically, relative to the present loads of anions and cations in precipitation. Higher concentrations of SO42−, NO3−, and base cations in runoff than in soil solutions are explained by lateral surficial leaching of pollutants and nutrients from shallow soil horizons. Nearly 30 years after peak acidification, UDL exhibited similar soil solution concentrations of SO42, Ca2+ and Mg2+ as median values at the Pan-European International Co-operative Program (ICP) Forest sites, yet NO3− concentrations were an order of magnitude higher.


Author(s):  
M.C.H.Mouat Pieter Nes

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.


Soil Research ◽  
1996 ◽  
Vol 34 (5) ◽  
pp. 679 ◽  
Author(s):  
Z Paydar ◽  
HP Cresswell

Different approaches were investigated for estimating the parameters in the Campbell soil water characteristic (SWC) equation from soil attributes such as particle size distribution (PSD), bulk density, and organic matter content. Predicted soil water characteristics were compared with measured values for soils of the wheatbelt of south-eastern Australia. A method of prediction is proposed incorporating an empirical relationship for estimating the slope of the SWC from the slope of the cumulative PSD. A power-law form is assumed for both the SWC and PSD functions. One measured SWC point is then used to locate and thus define the SWC curve. When SWC points predicted with this 'one-point' method were compared with measured values, the mean absolute value of the difference between each measured and predicted SWC point was 0.016 m3/m3 for the Geeves data and 0.027 m3/m3 for the Forrest data. Eight sets of predictive equations, previously developed using multiple regression analysis, were also evaluated. Whilst the equations predicted the slope of the SWC curves reasonably well, predictions of the air entry potential were poor. Although less accurate, the equations developed by multiple regression are less demanding in data requirement compared with alternative SWC prediction methods. The one-point method gave better predictions than the multiple regression approach but was less accurate than the 'two-point' method proposed in the first paper in this series. The one-point method should be considered where PSD data and 1 measured SWC point are available. In most other circumstances it will be more accurate and cost-effective to measure 2 SWC points to define the soil water characteristic function (the two-point method).* Part I, Aust. J. Soil Res., 1996, 34, 195–212.


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