Mobility of phosphorus through intact soil cores collected from the Adelaide Hills, South Australia

Soil Research ◽  
2000 ◽  
Vol 38 (5) ◽  
pp. 973 ◽  
Author(s):  
J. W. Cox ◽  
C. A. Kirkby ◽  
D. J. Chittleborough ◽  
L. J. Smythe ◽  
N. K. Fleming

Intact cores were collected from a variety of soils in the Adelaide Hills, South Australia, and tested for phosphorus retention and mobility (P in drainage) under various rainfall intensities (5, 25, and 50 mm/h). Phosphorus mobility was high in soils with significant macropore structure. However, all soils exhibited some degree of preferential flow of P, including the heavy-textured soils with high P adsorption that were not P saturated. A phosphorus adsorption index based only on the chemical properties of the soil did not accurately predict the mobility of P through soils with macroporosity. A phosphorus mobility index was developed encompassing both soil chemical and physical parameters. Results showed the sandy soils, and the loams over clays with high macroporosity that are located in the more elevated parts of the Adelaide hills, are most susceptible to P leaching. Management to reduce P loss to groundwater, streams, or surface water storages must aim to increase the residence time of P within soils and thereby allow mineral and organic fractions time to sorb P. Phosphorus loss through wet soils was significantly less than P loss through dry soils with high macroporosity. Application of P fertiliser to soils with high macroporosity may need to be delayed until later in the growing season than is currently practised.

Soil Research ◽  
1990 ◽  
Vol 28 (6) ◽  
pp. 981 ◽  
Author(s):  
JC Carlyle ◽  
JR Lowther ◽  
PJ Smethurst ◽  
EKS Nambiar

The relationship between selected chemical properties and nitrogen mineralization and nitrification was examined in soils collected from 39 sites of varying history. All sites were on podzolized sands; such soils represent more than 95% of the P. radiata growing area in south-east of South Australia/western Victoria. Given their uniformity in texture and similarity in pedogenesis, the organic matter concentrations of the sampled soils were highly variable (loss-on-ignition 0.8-10.2%). Total nitrogen was highly correlated with loss-on-ignition (r2 = 0.95, P<0.001). Nitrogen mineralization was correlated neither with total nitrogen nor loss-on-ignitition (i.e. P > 0.05), but was correlated with organic phosphorus (r2 = 0 70, P < 0.001), suggesting a major effect of phosphorus on nitrogen mineralization in these soils. On the basis of nitrate production during a 56-day aerobic incubation of disturbed soil, 18 soils were classed as strongly nitrifying (having a high potential to nitrify) and 18 as weakly nitrifying (having a low potential to nitrify). This separation reflected differences in other soil properties, with discriminant analysis giving a 91.7% correct classification into the two groups using only pH and Bray (II) extractable phosphorus for discrimination. Strongly and weakly nitrifying groups could also be discriminated on the basis of their value/chroma rating (after ignition), with a 94.4% probability of correct classification. Within each classification, nitrogen mineralization was correlated with total nitrogen (r2 =0.59 and 0.65, P< 0.001, for strongly and weakly nitrifying soils, respectively) but with a different relationship in each case. The significance of this difference in nitrogen dynamics is discussed in relation to site-specific forest management practices.


2013 ◽  
Vol 45 (3) ◽  
pp. 368-378 ◽  
Author(s):  
Egle Saaremäe ◽  
Martin Liira ◽  
Morten Poolakese ◽  
Toomas Tamm

Phosphorus (P) is one of the nutrients causing eutrophication in many of our waterways. In the present study, we investigated Sachtofer PR Ca-Fe oxide granules as a potential P sorption material (PSM) for constructed wetlands. We found the P sorption with various experiments as follows: the 24 h batch experiment with the highest initial concentration of 50 mgP L−1 yielded 0.48 mgP g−1 P removal per mass unit, the kinetic P removal batch experiment of 600 h duration yielded 1.25 mgP g−1, the maximum phosphorus adsorption capacity estimated from the Langmuir equation yielded 23.78 mgP g−1, and the long term flow-through experiment with drainage ditch water yielded indicative saturated sorption of 1.4 mgP g−1. Flow-through experiments revealed that phosphate removal was rapid and the efficiency was 10–70%, depending on the retention time and age of granules. Possible weaknesses of this material for sorption filter systems were found to include the loss of mass caused by the rapid dissolution of gypsum, increased sulfate and calcium concentrations in the water, and rapidly changing hydraulic conductivity. Considering hydraulic and chemical properties, further pilot experiments are necessary to develop technical solutions for optimal use of Ca-Fe oxide granules in sorption filter systems at constructed wetlands.


2012 ◽  
Vol 10 (H16) ◽  
pp. 171-171
Author(s):  
Klim Churyumov ◽  
Rudolf Belevtsev ◽  
Emlen Sobotovich ◽  
Svitlana Spivak ◽  
Tetyana Churyumova

AbstractIn 2007-2011 searches were conducted for mineralogical and geochemical studies of the soil in the region of fall down of a bright fireball EN171101 “Turyi Remety“ matter in Perechyn district of Transcarpathian. In the assumed location of the fall of a meteorite material for analysis was taken from the bottom of streams of Transcarpathian Mountains. In this matter we have been found numerous small magnetic spheres (microspherul) and fused segments, which have enough large sizes - up to 5 mm in diameter, which probably are fragments of the Turyi Remety meteoroid. One of the known signs of fireballs are sand-sized magnetic balls (by diameter 0.1-1.0 mm), which are often found in the magnetic concentrate fraction. This small balls, together with fragments of fused iotsit (FeO) are formed during the ablation of the meteoroid, and their sizes decreases during the motion of the meteoroid in the Earths atmosphere. From the east to the west, the radius of the balls in the study area decreased from an average of 0.7-0.5 mm to 0.1-0.3 mm. The sizes of such balls, as glowing molten particles of the meteoroid, are in good agreement with calculations based on the energy loss of the Turyi Remety meteoroid. This confirms the cosmic origin of these found small balls. Pre-calculated physical parameters of the Turyi Remety meteoroid are the velocity, mass, kinetic energy, the resistance force during ablation, the average fireball particle radius along trajectory path of a meteoroid fragments depending from the mass and size. Rapid mass loss of the meteoroid in more than 10 times, stronger, shorter ablation and damping fireball at the high altitude say about instability and the participation of the meteoroid gas in ablation. Perhaps the presence of ice, and other fireball gases in the meteoroid composition shows that its composition was close to comet one or to a chondrite with ice (gas hydrates). Especially likely gaseous hydrates of heavy gases such as CO2, H2S, hydrocarbons (propane, butane, etc.).


2020 ◽  
Author(s):  
Maria Rivera-Araya ◽  
Michael Bird ◽  
Cassandra Rowe ◽  
Sean Ulm ◽  
Vladimir Levchenko

&lt;p&gt;The selection and pre-treatment of a reliable organic fraction from which to acquire radiocarbon dates is fundamental to obtain accurate chronologies. Sampling from tropical lakes is particularly challenging given the adverse preservation conditions and diagenesis in these environments. Our research is the first to examine and quantify the differences between the radiocarbon date results from different carbon fractions and pretreatments from the same depths from a tropical lake sediment core (1.72 m long) located in north Australia to assess which one(s) are more reliable. Six different organic fractions (bulk organics, pollen concentrate, cellulose, stable polycyclic aromatic carbon (SPAC), charcoal &gt;250 um and charcoal &gt;63 um), for a total of 27 radiocarbon dates, were compared in six different depths along the core. Acid-base-acid (ABA), modified ABA (30 % hydrogen peroxide + ABA), 2chlorOx (a novel cellulose pre-treatment method) and hydrogen pyrolysis (hypy) were used to pre-treat the correspondent organic fractions. The oldest date is 31,295 calibrated years before present (cal yr BP) and the youngest is 2,048 cal yr BP, spanning 29,247 years. The smallest offset between the minimum and the maximum age in a given depth was found to be 975 years (between SPAC and charcoal &gt;63 um) and the largest 16,527 years (between pollen concentrate and SPAC). The SPAC fractions pre-treated with hypy consistently yielded older ages compared to all other fraction in most cases, while bulk organics yielded consistently younger ones. The magnitude and consistency of the offsets and the physical and chemical properties of the tested organic fractions suggest that SPAC is the most reliable fraction to date in tropical lake sediments and that hypy successfully removes contamination sourced from exogenous carbon.&lt;/p&gt;


2005 ◽  
Vol 85 (3) ◽  
pp. 417-426 ◽  
Author(s):  
D V Ige ◽  
O O Akinremi ◽  
D N Flaten ◽  
B. Ajiboye ◽  
M A Kashem

The establishment of the P retention capacity of soil in Manitoba is essential for effective management of P in the region. However, the methods for determining the P retention capacity for neutral to calcareous soils in the Eastern Prairies are not well developed. The objectives of this study were to determine the P retention capacity of Manitoba soils and to generate equations that relate these capacities to other soil properties. One hundred and fifteen archived surface soils were selected and their physico-chemical properties were measured. These soils were used to generate a single-point P adsorption index by equilibrating 2 g of soil in 20 mL of 0.01 M KCl solution containing either 150 (P150) or 400 (P400) mg P L-1. A subset of 26 of these soils was used for multipoint isotherms with P concentrations in the range of 0–1000 mg P L-1. The data obtained were fitted to the Langmuir isotherm and the adsorption indices were correlated with the various soil properties that were then used to developed predictive equations of the P retention capacity of the soil. The values of the adsorption index, P150, obtained from the single point adsorption study using 150 mg P L-1, ranged between 88 and 891 mg P kg-1, while that of P400 ranged between 100 and 1250 mg P kg-1. A better correlation was obtained between P150 and soil properties compared with P400. For the 26 soil subset, the adsorption indices, Smax1 to Smax 6, obtained from the Langmuir isotherm, ranged from 300 to 1330 mg kg-1. A good correlation was obtained between the single point index and the multipoint isotherm (r = 0.93). Hence, Smax for the 115 soils was estimated from the relationship between P150 and Smax 3 of the 26 soils. The best relationships between the adsorption parameters, P150 and Smax, and the soil properties were obtained with the sum of Mehlich-3 extractable Ca and Mg (R2= 0.66) and the sum of exchangeable Ca and Mg (R2= 0.64). Mehlich-3-Ca and -Mg each explained 56% of the variation, while clay content explained 40% of the variation in the P retention capacity of these soils. Unlike the widely reported influence of Al and Fe in acid soils, our study showed that the retention of P in Manitoba soils was influenced more by Ca and Mg and soil texture. Key words: Phosphorus, phosphorus retention capacity, phosphorus adsorption capacity, phosphorus sorption, single-point index


RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37441-37446 ◽  
Author(s):  
Qingzhi Wang ◽  
Jiankun Liu ◽  
Lingqing Wang

Freeze–thaw cycles (FTCs) can strongly influence the physical and chemical properties of soils in cold regions, which can in turn affect the adsorption–desorption characteristics of phosphorus (P) in the soil.


2016 ◽  
Vol 705 ◽  
pp. 204-208
Author(s):  
Siti Nasuha Rafien ◽  
Azman Kasim ◽  
Azhan Hashim ◽  
S. Akmal Syamsyir ◽  
Mardhiah Abdullah ◽  
...  

Tellurite glasses were generally applied in rare earth optical materials due to their excellent in physical and chemical properties. In this study, tellurite glasses composed of (70-x)TeO2-20B2O3-10ZnO-xSm2O3 (x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) were prepared by conventional melt-quenching technique. Some basic physical parameters such as density, molar volume and oxygen packing density as well as the optical analysis by mean of their absorption and emission spectra have been carried out at room temperature using UV/Vis and photoluminescence spectrophotometer. The result of physical properties are found to vary with respect to concentration of Sm3+ ions content. Meanwhile, three strong absorption peaks are observed and are well resolved in the ultra violet and visible regions due to transitions between the ground state and various excited state of Sm3+ ions. Under 480nm laser excitation, luminescence spectra exhibit four emission bands at 562 nm, 599 nm, 645 nm and 706 nm which corresponding to the transition 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 were observed. Some other results were also been analysed and presented.


2020 ◽  
Vol 19 (3) ◽  
pp. 73-81
Author(s):  
Piotr Siwek ◽  
Iwona Domagała-Świątkiewicz ◽  
Andrzej Kalisz ◽  
Piotr Bucki

In 2014–2015 at the experimental station of the University of Agriculture in Kraków, situated in Mydlniki near Kraków, Poland, experiments with intensive crop rotation in a high tunnel were conducted. The objectives concerned microclimatic zones in the tunnel and the yield and quality of butterhead lettuce (spring), cucumber (summer), and butterhead lettuce (autumn). Besides the properties of the soil in the high tunnel, a crucial role was played by microclimatic factors. The measurements showed variations in solar radiation, temperature and air humidity depending on the zone in the tunnel and the weather. Higher temperature in the centre of the tunnel was conducive to obtaining greater yields of spring lettuce and cucumber. In the spring and summer periods, the amounts of dry matter and total sugars in the edible parts of the cultivated vegetables were higher in the eastern and central zones of the tunnel. In the autumn, with less solar radiation, the amount of sugars in lettuce leaves was greater in the western zone. There was observable influence of the location in the tunnel from which samples were taken for analyses (zonal effect) on some physical parameters of the soil (bulk density, water capacity, and water-stability index).


2021 ◽  
Vol 2 (1) ◽  
pp. 68-79
Author(s):  
Charu Shahi ◽  
◽  
SS Bargali ◽  
Kiran Bargali ◽  
◽  
...  

The present study has been performed among Central Himalayan agroecosystems (AGEs) to analyze the changes in some physico- chemical properties of soils along four altitudes viz. very low (VLA), low (LA), mid (MA) and high altitude (HA). The AGEs were categorized into three size classes i.e. small, medium, and large based on the regional availability of landholding sizes. Results revealed that the size of the AGEs significantly affected only physical parameters of the soil while chemical parameters remain unaffected, this may be due to the regional similarity in management practices of AGEs which governed by the identical seasonal cropping patterns, local food selectivity and economic status of the peasant. The soil bulk density was recorded maximum at VLA (1.00 g cm-3) and decreased with increasing altitude and sizes of agroecosystem thus the correlations were significant. Water holding capacity depicted positive relation with porosity (r= 0.229, P<0.01) and OC (r= 0.273) while negative relation with silt (r= -0.172), bD (r= -0.221,) and pH (r= -0.081). Soil nitrogen was reported highest at MA in medium sized agroecosystems, during the rainy season (0.287 %) followed by winter (0.257 %) and summer season (0.243 %). Overall maximum soil carbon stock was observed at MA (41.41 t ha-1) > HA (37.85 t ha-1) > LA (33.00 t ha-1) > VLA (30.16 t ha-1). Suitable management practices of higher altitudes reflected as the high fertility of the soil in those regions (SQI= HA> MA> LA> VLA) which must be followed by the farm managers of lower altitudes.


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