scholarly journals Temperature dependence of phosphate sorption in mineral soils

1990 ◽  
Vol 62 (1) ◽  
pp. 17-20
Author(s):  
Raina Niskanen
Keyword(s):  
Ionic Strength ◽  
Temperature Dependence ◽  
Mineral Soil ◽  
Soil Samples ◽  
Phosphate Sorption ◽  
Mineral Soils

The sorption of phosphate was studied in 33 mineral soil samples at the temperatures of +5°C and +20°C. The soils were equilibrated for 2 days with a solution containing phosphate 0.1 mmol/l at an ionic strength of 0.01. At +5°C, the sorption remained unchanged or increased slightly as compared to the sorption at +20°C. The differences between sorbed amounts ranged from —0.03 to 0.29 mmol/kg soil and were statistically significant in 11 samples.

scholarly journals Príspevok k problematike určovania špecifickej hmotnosti subhorizontov opadu lesných pôd

2013 ◽  
Vol 59 (1) ◽  
pp. 38-43
Author(s):  
Jana Bútorová
Keyword(s):  
Mineral Soil ◽  
Soil Aggregate ◽  
Soil Samples ◽  
Organic Soils ◽  
Laboratory Methods ◽  
Elementary Unit ◽  
Final Density ◽  
International Laboratory ◽  
Mineral Soils

Abstract According to national and international laboratory methods, the density of soil samples is determined by pycnometer in heated samples crushed by ultrasound. In mineral soils, the elementary unit of density is represented by a mineral grain of quartz, granite, andesite, etc. On the other hand, in organic soils, the elementary unit is represented by a leaf (or just a part of it), needles, stems and roots. Heating of the mineral grain causes its release from the soil aggregate. Organic parts of the soil are losing air vacuoles by heat treatment while in the same time, carbohydrates, proteins, oils and resins create new chemicals which are heavier than water. That is a reason why density determination of litter subhorizons in forest soils needs to have different rules in comparison with mineral soil samples. Samples with more than 50 volume per cent of organic matter are not treated by heat and do not decompose. In case of high mineral soil content, mineral parts are removed from the sample and their density is determined. The final density is based on mathematically processed data.

scholarly journals Sorption capacity of phosphate in mineral soils: I Estimation of sorption capacity by means of sorption isotherms

1990 ◽  
Vol 62 (1) ◽  
pp. 1-8
Author(s):  
Raina Niskanen
Keyword(s):  
Ionic Strength ◽  
Sorption Capacity ◽  
Sorption Isotherms ◽  
Clay Content ◽  
Langmuir Equation ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Sorption Data ◽  
Mineral Soils ◽  
Extractable Al

The sorption capacity of phosphate in seven soil samples (clay content 1—70 %, organic carbon content 0.8—10.7 %, soil pH 4.2—5.3, oxalate-extractable Al 11—222 and Fe 11—202 mmol/kg soil) was studied by means of sorption isotherms. The soils were equilibrated, for two to seven days at +5 and +20°C, with solutions containing phosphate 0—10 mmol/l (0—200 mmol/kg soil) at a constant ionic strength of 0.01 . Prolongation of the reaction time increased the sorption of phosphate only partially. The rise in temperature, from +5 to +20°C, increased the sorption from higher phosphate concentrations. At +20°C, the sorption curves of three soils showed a sorption maximum of 4, 19 and 34 mmol/kg soil. The sorption data of six soils was in accordance with the Langmuir equation; the sorption maximum ranged from 15 to 119 mmol/kg soil, and were of the same magnitude as the maximums determined experimentally.

scholarly journals Chloride and sulphate solutions as extractants for soil P: III Effect of increasing sulphate concentration on P desorption 

1983 ◽  
Vol 55 (4) ◽  
pp. 363-369
Author(s):  
Helinä Hartikainen ◽  
Markku Yli-Halla
Keyword(s):  
Ionic Strength ◽  
Mineral Soil ◽  
Soil Samples ◽  
Constant Ionic Strength ◽  
Oxide Surfaces ◽  
Promoting Effect ◽  
Soil P ◽  
Sulphate Concentration ◽  
Extraction Power ◽  
P Desorption

The effect of increasing sulphate concentration on P desorption was studied in 102 mineral soil samples with: a) solutions of a constant ionic strength I=0.1 adjusted with KCI and b) 0.1 M and 0.033 M sulphate solutions of different ionic strengths. Further, the efficiency of chloride and sulphate solutions of equal anion concentration (0.1 M) was compared. At a constant ionic strength, P desorption was enhanced as the sulphate concentration of the extractant increased. Even despite a much higher ionic strength the extraction power of the K2SO4 solution was greater than that of the KCI solution of the same anion concentration. Comparison of the 0.1 M and 0.033 M K2SO4 solutions revealed in 53 soil samples the extractability of P to be depressed by an increase in sulphate concentration (and ionic strength). In 49 samples, on the contrary, the 0.1 M K2SO4 solution extracted equal or greater P amounts than did the 0.033 M K2SO4. It was observed that the lower the P coverage on the oxide surfaces in the soil was, the more obviously the promoting effect of increasing sulphate concentration overruled the depression induced by increasing ionic strength, and the more superior the K2SO4 solution was as compared to the KCI solution.

scholarly journals Sorption capacity of phosphate in mineral soils: II Dependence of sorption capacity on soil properties

1990 ◽  
Vol 62 (1) ◽  
pp. 9-15
Author(s):  
Raina Niskanen
Keyword(s):  
Soil Properties ◽  
Sorption Capacity ◽  
Mineral Soil ◽  
Clay Content ◽  
Organic C ◽  
Phosphate Sorption ◽  
P Sorption ◽  
P Sorption Capacity ◽  
Mineral Soils ◽  
Extractable Al

The dependence of the indicator of phosphate sorption capacity on extractable Al and Fe and other soil properties was studied in a material consisting of 102 mineral soil samples. The sum of P adsorbed on soil during two days from a solution containing P 5 mmol/l and P extracted by 0.02 M EDTA (pH 5.3) as an estimate of the initial P content in the soil was used as the indicator of P sorption capacity. In clay and silt soils (n = 51), the Al and Fe extracted by 0.05 M oxalate (pH 2.9) together with the organic C content explained 85 %, the Al and Fe extracted by 0.05 M K4P2O7 (pH 10) together with the clay content 87 %, the Al and Fe extracted by 0.02 M EDTA (pH 5.3) 91 %, and the Al extracted by 1 M CH3COONH4 (pH 4.8) together with the organic C and clay contents 78 % of the variation of the indicator of phosphate sorption capacity. In coarse soils (n = 51), the variation of the indicator was explained well only by oxalate-extractable metals, which together with soil pH and clay content explained 80 % of the variation. Extractable Al was generally the most important explainer of variation. The results suggest that forms of extractable Al and Fe explaining the variation of the indicator of P sorption capacity in clay and silt soils are partially different from those in coarse soils.

scholarly journals Desorption of phosphate from three Finnish mineral soil samples during adsorption of vanadate, molybdate and tungstate

1994 ◽  
Vol 3 (5) ◽  
pp. 481-486 ◽  
Author(s):  
Anneli Mikkonen ◽  
Jouni Tummavuori
Keyword(s):  
Adsorption Process ◽  
Mineral Soil ◽  
Soil Samples ◽  
Equilibration Time ◽  
Aqueous Chemistry ◽  
Series Of Experiments ◽  
Mineral Soils ◽  
Ph Range ◽  
Suspension Ph

Adsorption of V(V) and Mo(VI) from 10-4 M and 10-5 M solutions and W(VI) from a 10-4 M solution (in 0.02 M KCI) by three Finnish mineral soils was studied in two series of experiments. In the first experiment, the adsorption of V, Mo and W by soil and the desorption of P were measured at the soils’ natural pH after an equilibration time of 3, 5, 22, 29, 46 and 70 h. Adsorption of molybdate occurred mainly within the three first hours, whereas adsorption of vanadate and tungstate were slower processes. During the first few hours, the presence of molybdate seemed to increase the desorption of phosphate most effectively, but after a longer equilibration period, the differences between additions of V, Mo, and W became smaller. In the second experiment, the adsorption process was followed as a function of the acidity of the suspension (pH 2.3-7.5; for W pH 2.8-7.5). Adsorption of V(V), Mo(VI) or W(VI) resulted in a statistically significant increase in the amounts of P desorbed from all three soils over the pH range studied. The aqueous chemistry of V(V), Mo(VI) and W(VI) is briefly discussed.

scholarly journals Arsenic and heavy metal concentrations in agricultural soils in South Savo province

2002 ◽  
Vol 11 (4) ◽  
pp. 285-300 ◽  
Author(s):  
V. MÄNTYLAHTI ◽  
P. LAAKSO
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Agricultural Soils ◽  
Mineral Soil ◽  
Soil Samples ◽  
Potential Hazard ◽  
Metal Concentrations ◽  
Limit Values ◽  
Heavy Metal Concentrations ◽  
Target Values

Increasing concentrations of arsenic and heavy metals in agricultural soils are becoming a growing problem in industrialized countries. These harmful elements represent the basis of a range of problems in the food chain, and are a potential hazard for animal and human health. It is therefore important to gauge their absolute and relative concentrations in soils that are used for crop production. In this study the arsenic and heavy metal concentrations in 274 mineral soil samples and 38 organogenic soil samples taken from South Savo province in 2000 were determined using the aqua regia extraction technique. The soil samples were collected from 23 farms.The elements analyzed were arsenic, cadmium, chromium, copper, mercury, nickel, lead and zinc. The median concentrations in the mineral soils were:As 2.90 mg kg –1, Cd 0.084 mg kg –1, Cr 17.0 mg kg –1, Cu 13.0 mg kg –1, Hg 0.060 mg kg –1, Ni 5.4 mg kg –1, Pb 7.7 mg kg –1, Zn 36.5 mg kg –1. The corresponding values in the organogenic soils were:As 2.80 mg kg –1, Cd 0.265 mg kg –1, Cr 15.0 mg kg –1, Cu 29.0 mg kg –1, Hg 0.200 mg kg –1, Ni 5.9 mg kg –1, Pb 11.0 mg kg –1, Zn 25.5 mg kg –1. The results indicated that cadmium and mercury concentrations in the mineral and organogenic soils differed. Some of the arsenic, cadmium and mercury concentrations exceeded the normative values but did not exceed limit values. Most of the agricultural fields in South Savo province contained only small amounts of arsenic and heavy metals and could be classified as “Clean Soil”. A draft for the target values of arsenic and heavy metal concentrations in “Clean Soil” is presented.;

scholarly journals Sulphur status in Finnish cultivated soils

1973 ◽  
Vol 45 (2) ◽  
pp. 121-215
Author(s):  
Johan Korkman
Keyword(s):  
Ammonium Acetate ◽  
Induction Furnace ◽  
Soil Samples ◽  
Total Sulphur ◽  
Sulphate Sulphur ◽  
Close Relationship ◽  
Mineral Soils ◽  
Sulphur Uptake ◽  
Cultivated Soils

A method for determining total sulphur in plant material and soil samples using the induction furnace technique and subsequent turbidimetric determination of sulphate sulphur was discussed. A procedure for extracting sulphur from soil samples with ammonium acetate (pH 4.65), the interference of the organic matter being reduced by oxidation of the extract with H2O2, was proposed. Sulphur balance in Finnish cultivated soils was estimated by taking into account the average amounts of emitted (8 kg S/ha/yr.), precipitated (8 kg S/ha/yr.) and leached (8 kg S/ha/yr.) sulphur. The actual situation in the cultivated soils seems thus to be depending, on an average, on the uptake by plants and the sulphur applied (12 kg S/ha/yr. in the early 1970s). In 104 samples of cultivated soil, the content of total sulphur showed a slight correlation with the content of organic carbon. The amounts of sulphur extracted in various ways were not predictable by means of the soil characteristics used (pHCaCl2, org. C and texture). Extracted sulphur did not correlate sufficiently with the development and sulphur uptake of plants. Under field conditions in northern Finland, sulphur application produced a relatively distinct result in respect both to the ley yields on Carex peat, and their sulphur content. On mineral soils in southern Finland the yields were unaffected by supplementary fertilization with sulphur. In the pot experiments performed a fairly close relationship between sulphur and nitrogen was demonstrated.

scholarly journals CHARACTERISTICS OF RICE SOILS FROM THE TIDAL FLAT AREAS OF MUSI BANYUASIN, SOUTH SUMATRA

2016 ◽  
Vol 2 (1) ◽  
pp. 10 ◽  
Author(s):  
B.H. Prasetyo ◽  
S. Suping ◽  
Subagyo H. ◽  
Mujiono Mujiono ◽  
H. Suhardjo
Keyword(s):  
Organic Carbon ◽  
Tidal Flat ◽  
Amorphous Materials ◽  
Mineral Soil ◽  
Soil Samples ◽  
Moisture Regime ◽  
Organic Carbon Content ◽  
Rice Soils ◽  
Specific Chemical ◽  
Very High

Tidal flats in the Musi Banyuasin region that cover more than 200,000 ha are the largest area for agricultural development in South Sumatra Province. Only about a half of this has been used for tidal swamp rice fields, therefore, the other half needs to be developed. To obtain a better understanding of their properties for appropriate soil management, soil characteristics of the area need to be studied. To characterize the soil, thirty-four soil samples from seven soil profiles were analyzed for their chemical and mineralogical composition at the laboratories of the Center for Soil and Agroclimate Research and Development. The results indicate that soils from the tidal flat areas have an aquic soil moisture regime, the upper parts of the soils are mostly ripe, and most of the pedons show the presence of sulfidic materials below 65 cm of the mineral soil surface. The soils are classified as Sulfic Endoaquept (P1, P2), Histic Sulfaquent (P3), Typic Sulfaquept (P4), Fluvaquentic Endoaquept (P5), and Sulfic Hydraquent (P6, P7). Mineral composition of the sand fraction is dominated by quartz, while the clay minerals consist of predominantly kaolinite, mixed with small amount of smectite, illite, quartz, and crystoballite. Organic carbon content is high to very high, potential phosphate content of most pedons ranges from very low to medium, while potential potassium content varies from very low to medium in the upper layers and medium to very high in the bottom layers. Phosphate retention of topsoil sample varies from 56 to 97%, and is positively correlated (r2 = 0.73) with aluminum from amorphous materials. Exchangeable cations are dominated by Mg cation, and in all pedons cation exchange capacity values are medium to very high, and seem to be influenced by organic carbon. Specific chemical properties, particularly soil pH and content of exchangeable aluminum exhibit a significant change about 1-2 months after soil samples were taken from the field. Theoretically, interaction between good water management and fertilizer application are among the choices of management to make these soils productive.

CHARACTERISTICS OF THE EPIDERMAL LAYER OF CARROT ROOTS GROWN ON PEAT AND MINERAL SOIL

1971 ◽  
Vol 51 (6) ◽  
pp. 513-517
Author(s):  
E. W. CHIPMAN ◽  
F. R. FORSYTH
Keyword(s):  
Ascorbic Acid ◽  
Dry Matter ◽  
Reducing Sugars ◽  
Peat Soil ◽  
Mineral Soil ◽  
Epidermal Layer ◽  
Peat Soils ◽  
Anti Oxidant ◽  
Mineral Soils

The epidermal layer of carrot roots grown on peat soil contained more ascorbic acid and less phenols, carotene, reducing sugars, and dry matter than those from a mineral soil. The increased level of phenol and the decreased level of the anti-oxidant ascorbic acid are the likely contributing causes of the increased browning of carrots in mineral soils relative to peat soils.

scholarly journals Effects of land use change from natural forest to plantation on C, N and natural abundance of 13C and 15N along a climate gradient in eastern China

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mbezele Junior Yannick Ngaba ◽  
Ya-Lin Hu ◽  
Roland Bol ◽  
Xiang-Qing Ma ◽  
Shao-Fei Jin ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Forest Floor ◽  
Eastern China ◽  
Mineral Soil ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Natural Forests ◽  
Soil C ◽  
Mineral Soils

Abstract Soil C and N turnover rates and contents are strongly influenced by climates (e.g., mean annual temperature MAT, and mean annual precipitation MAP) as well as human activities. However, the effects of converting natural forests to intensively human-managed plantations on soil carbon (C), nitrogen (N) dynamics across various climatic zones are not well known. In this study, we evaluated C, N pool and natural abundances of δ13C and δ15N in forest floor layer and 1-meter depth mineral soils under natural forests (NF) and plantation forest (PF) at six sites in eastern China. Our results showed that forest floor had higher C contents and lower N contents in PF compared to NF, resulting in high forest floor C/N ratios and a decrease in the quality of organic materials in forest floor under plantations. In general, soil C, N contents and their isotope changed significantly in the forest floor and mineral soil after land use change (LUC). Soil δ13C was significantly enriched in forest floor after LUC while both δ13C and δ15N values were enriched in mineral soils. Linear and non-linear regressions were observed for MAP and MAT in soil C/N ratios and soil δ13C, in their changes with NF conversion to PF while soil δ15N values were positively correlated with MAT. Our findings implied that LUC alters soil C turnover and contents and MAP drive soil δ13C dynamic.

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