Chemical fertility of krasnozems - a review

Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.

Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.


2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nenad Tomašić ◽  
Štefica Kampić ◽  
Iva Cindrić ◽  
Kristina Pikelj ◽  
Mavro Lučić ◽  
...  

AbstractThe adsorption properties in terms of cation exchange capacity and their relation to the soil and sediment constituents (clay minerals, Fe-, Mn-, and Al-oxyhydroxides, organic matter) were investigated in loess, soil-loess transition zone, and soil at four loess-soil sections in North-Western Croatia. Cation exchange capacity of the bulk samples, the samples after oxalate extraction of Fe, Mn and Al, and after removal of organic matter, as well as of the separated clay fraction, was determined using copper ethylenediamine. Cation exchange capacity (pH∼7) of the bulk samples ranges from 5 to 12 cmolc/kg in soil, from 7 to 15 cmolc/kg in the soil-loess transition zone, and from 12 to 20 cmolc/kg in loess. Generally, CEC values increase with depth. Oxalate extraction of Fe, Mn, and Al, and removal of organic matter cause a CEC decrease of 3–38% and 8–55%, respectively, proving a considerable influence of these constituents to the bulk CEC values. In the separated clay fraction (<2 μm) CEC values are up to several times higher relative to those in the bulk samples. The measured CEC values of the bulk samples generally correspond to the clay mineral content identified. Also, a slight increase in muscovite/illite content with depth and the vermiculite occurrence in the loess horizon are concomitant with the CEC increase in deeper horizons, irrespective of the sample pretreatment.


Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 11-16 ◽  
Author(s):  
R. L. Hollist ◽  
C. L. Foy

Concentrations ofα,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) causing 50% growth reduction (hereinafter referred to as GR50) were determined in nutrient culture and 64 simulated soils using foxtail millet (Setaria italica(L.) Beau.) as an indicator species. The relative order of effectiveness of soil components in reducing trifluralin phytotoxicity was steamed organic matter ≫ organic matter ≫ steamed montomorillonite ≥ steamed kaolinite ≃ kaolinite ≃ montmorillonite. Steaming the organic matter more than doubled the anion exchange capacity. Anion exchange capacity was a better parameter than cation exchange capacity for assessing the potential of an adsorbent to reduce phytotoxicity. Surface area, cation exchange capacity, and adsorption of trifluralin from solution were less reliable indices. The effectiveness of organic matter in reducing phytotoxicity may be due to the exchange capacity and high surface area. Montomorillonite apparently interacted synergistically with other adsorbents to reduce phytotoxicity. Trifluralin did not adsorb on the internal surfaces of montmorillonite as judged by surface area comparisons and X-ray diffraction determinations. Increasing moisture content appeared to block the active sites of trifluralin adsorption. This may be concluded from greater vapor movement and decreased adsorption from a xylene solvent system for moist compared to air dry soils.


Clay Minerals ◽  
2012 ◽  
Vol 47 (4) ◽  
pp. 499-511 ◽  
Author(s):  
A. Mbaye ◽  
C. A. K. Diop ◽  
B. Rhouta ◽  
J. M. Brendle ◽  
F. Senocq ◽  
...  

AbstractThere is interest in exploiting and developing natural resources, particularly deposits of natural clays. Senegal has several clay mineral deposits for which chemical and mineralogical compositions have been little studied. Some of these natural materials are nowadays used in pottery and ceramics. To extend applications, a better basic knowledge is required and, for this objective, the raw clay and separated <2 μm clay fraction from Keur Saër (Senegal) were subjected to chemical and mineralogical studies. Several techniques including X-ray diffraction (XRD), thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), N2 adsorption-desorption isotherms, cation exchange capacity (CEC) measurements and solid state nuclear magnetic resonance (NMR) have been used to characterize the material. It was found that the raw clay and the separated clay fraction consist of a mineral mixture in which kaolinite is the main component. 29Si and 27Al MAS-NMR spectra show the presence of silicon atoms linked to three other silicon atoms via an oxygen atom and six coordinated Al atoms. Significant increases in the specific surface area and cation exchange capacity were observed on purification, reaching a maximum of about 73.2 m2g–1 and 9.5 meq/100 g for the separated fine clay fraction while the values for the raw material were around 28.9 m2g–1 and 7.3 meq/100 g.


2012 ◽  
Vol 500 ◽  
pp. 142-148 ◽  
Author(s):  
Wen Xing Lü ◽  
Hong Jiang Zhang ◽  
Yu He Wu ◽  
Jin Hua Cheng ◽  
Jian Qiang Li ◽  
...  

Through the research and sampling analysis on different plant hedgerow in sloped farmland in Three Gorges reservoir area, we will conduct research on the impact of plant hedgerow in Three Gorges on the chemicophysical properties of soil and soil erosion. The results show that the plant hedgerow mainly composed by Morus alba, Citrus reticulata, Zanthoxylum bungeanum, Vitex negundoand Begonia fimbristipula can decrease the soil density as well as sand content and increase soil porosity, soil water content, silt content and clay content to some extent. The organic matter, nitrogen, phosphorus, potassium and cation exchange capacity and other chemical indices of soil in different locations in plant hedgerow indicate as maximum in on-band, minimum in inter-band, middle both upper-band and below-band. In the same slop with no plant hedgerow, the organic matter, nitrogen, phosphorus, potassium and cation exchange capacity and other chemical indices of soil show a trend of increasing from the top to the bottom of the slop, which reveals that these substances own a feature of accumulation by moving to the bottom. The strength of soil anti-corrosion in different plant hedgerow is: Vitex negundoand (79.2%)> Citrus reticulata (36.4%)> Morus alb (22.4%)> Zanthoxylum bungeanum (18.9%)> Begonia fimbristipula (15.3%)> CK (8.7%), and the soil anti-corrosion indices in plant hedgerow are decreasing with the increase of soil immersion time, besides, the former and the latter are 3 times polynomial function. For those 5 plant hedgerows, Vitex negundoand owns the best impact on improving soil chemicophysical properties and reducing soil erosion.


2017 ◽  
Vol 29 (2) ◽  
pp. 123-131
Author(s):  
Reshma Akter ◽  
Md Jamal Uddin ◽  
Md Faruque Hossain ◽  
Zakia Parveen

A study was carried out to evaluate the effects of brick manufacturing on phosphorus (P) and sulfur (S) concentrations in soil and plant collected from different distances of brick kilns in four AEZs of Bangladesh. Forty eight composite soil samples (0 - 15 cm depth) were collected from 48 points in 12 different sites at 0 m, 300 m, 800 m and 1500 m from brick kilns, where most (site 2, site 3, site 5, site 6, site 7, site 9 and site 10) of the brick kilns used coal for brick burning purposes. Plant samples (rice straw and different vegetables) were also collected from the respective fields except 0 m distances. Significantly (p ? 0.05) lower organic matter, cation exchange capacity, clay content and soil pH were found at 0 m distances compared to other distances. Highest concentration of total P in soil were recorded at 0 m distances and these concentrations decreased with increasing distances from the brick kilns in most of the sites; whereas available P is significantly lower at 0 m distances than that of other distances. Total and available concentration of S in soil followed the trend 0 m>300 m>800 m>1500 m. Maximum accumulation of P (69.15 mg kg-1) and S (0.14%) in plant was found at 800 m away from the brick kiln.Bangladesh J. Sci. Res. 29(2): 123-131, December-2016


1989 ◽  
Vol 67 (2) ◽  
pp. 460-465 ◽  
Author(s):  
Conrad Richter ◽  
Jack Dainty

Isolated delignified cell walls from Sphagnum russowii Warnsdorf were incubated in various chloride salt solutions at neutral pH (pH 7 – 8), and ion sorption was measured directly by neutron activation analysis. The anion-exchange capacity was estimated to be 63 – 66 μequiv./g dry weight of wall material in the protonated form. The volume of the anion-exclusion space was 2.63 ± 0.21 (± SD, n = 3) and 1.65 ± 0.35 (± SD, n = 2) mL/g dry weight in NaCl and CaCl2, respectively. A novel approach to measure the Donnan free space is proposed: for walls equilibrated in a salt mixture containing 10 mequiv./L NaCl and 10 mequiv./L CaCl2, the Na+ ions can be considered "uncondensed" in the Manning sense. From the Donnan relationship for Na+ and Cl− ions in the internal and external phases, the Donnan free space was calculated to be 1.77 mL/g dry weight. Titrating walls from pH 2.1 to 9.1 in the presence of 10 mequiv./L NaCl and 10 mequiv./L CaCl2 revealed a maximum cation-exchange capacity above pH 6 of ca. 1900 μequiv./g dry weight. This corresponds to a fixed anionic charge concentration in the Donnan free space of 1.1 M. Key words: ion exchange, cell wall, Donnan free space.


1968 ◽  
Vol 48 (1) ◽  
pp. 53-63 ◽  
Author(s):  
J. S. Clark ◽  
W. E. Nichol

Heating in hydrogen peroxide, dilute oxalic acid, and dilute aluminum oxalate did not change the effective cation exchange capacity (CEC) or the pH-7 CEC of Wyoming bentonite and Alberni clay soil containing excess Al(OH)x. This indicated that treatment of soils with H2O2 to oxidize organic matter and the possible production of oxalates during oxidation did not change the CEC values of the inorganic fraction of soils even if some clay exchange sites were blocked by hydrous oxides of Al.With soils of pH less than approximately 5.4, oxidation of organic matter did not change the effective CECs although the pH-7 CEC values were decreased. Thus, organic matter in acid soils appeared to have little or no effective CEC. Because of this and the negligible effect of H2O2 oxidation on the CEC values of clays, the difference of the pH-7 CEC of soils before and after H2O2 oxidation provided a simple means of estimating the amount of organic pH-dependent CEC in acid soils.The amount of organically derived pH-dependent CEC was determined in a number of soils by means of peroxide oxidation. The technique provided a useful indication of the quantities of sesquioxide–organic matter complexes accumulated in medium- and fine-textured soils.


1999 ◽  
Vol 79 (3) ◽  
pp. 501-504 ◽  
Author(s):  
B. J. Zebarth ◽  
G. H. Neilsen ◽  
E. Hogue ◽  
D. Neilsen

Sandy, infertile soils can benefit from the addition of organic waste amendments. Annual applications of organic wastes for as long as 4 yr increased soil organic matter content, decreased soil bulk density, and increased soil water retention of a coarse-textured soil. However, soil water-holding capacity was not necessarily increased, and there was a limited effect on soil cation exchange capacity. Key words: Cation exchange capacity, water retention, soil pH, soil organic matter, soil bulk density


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