scholarly journals Changes in soil organic matter, enzymatic activities and heavy metal availability induced by application of organic residues

2002 ◽  
pp. 353-362 ◽  
Author(s):  
P. Burgos ◽  
E. Madejón ◽  
F. Cabrera
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Enzymatic Activities ◽  
Metal Availability ◽  
Organic Residues

scholarly journals Total and bioavailable forms of Cu, Zn, Pb and Cr in agricultural soils: a study from the hydrological basin of Keritis, Chania, Greece

2013 ◽  
Vol 9 (3) ◽  
pp. 201-206 ◽  
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Agricultural Soils ◽  
Agricultural Area ◽  
Metal Concentrations ◽  
Aqua Regia ◽  
Heavy Metal Concentrations ◽  
Agricultural Areas

The hydrological basin of Keritis in Chania, Greece is mainly an agricultural area where various agrochemicals are used. In topsoils, the total and available forms of Cu, Zn, Pb and Cr were determined after their extraction with boiling Aqua Regia and DTPA respectively. Although the total heavy metal concentrations in Keritis soils were similar to the total concentrations in other agricultural areas, the studied soils can not be described as heavily polluted. The bioavailable concentrations of Cu, Zn, Pb and Cr were low. The relative availability and comparative mobility followed the order of Cu>Pb>Zn>Cr and was closely related to the soil organic matter.

scholarly journals Edaphic macrofauna in degradation of animal and vegetable residues

2019 ◽  
Vol 79 (4) ◽  
pp. 589-593 ◽  
Author(s):  
R. N. Schubert ◽  
T. B. G. A. Morselli ◽  
S. M. Tonietto ◽  
J. M. O. Henriquez ◽  
R. D. Trecha ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Experimental Design ◽  
Chemical Analysis ◽  
Animal Origin ◽  
Eisenia Foetida ◽  
Organic Residues ◽  
Volumetric Density ◽  
Decomposition Processes ◽  
Randomized Experimental Design

Abstract The objective of this study was to evaluate the ability to degrade organic matter by edaphic macrofauna (worms), carbon/nitrogen (C/N) ratio and hydrogenation potential (pH) during the vermicomposting process in different organic residues. The treatments were constituted by organic residues of animal origin (bovine, ovine and equine manure) and vegetable (herb-checkmate and coffee drag), which were conditioned in plastic pots with a capacity of 10 liters, comprising five treatments in a completely randomized experimental design, with five replications. Were inoculated 150 earthworms of the species Eisenia foetida, into each plot. After 87 days, the evaluation of the multiplication of the earthworms was carried out, through its manual count and its cocoons. At the beginning and at the end of the experiment, the samples were submitted to analysis of humidity at 60 °C, pH, volumetric density, chemical analysis of macronutrients and C/N ratio. There was a dominance of worms and cocoons in the process of vermicomposting in the residues of ovine manure and herb-checkmate. The macronutrients (P, K and Mg) and C/N ratio were higher in the vegetal residues, while for N higher values were found in ovine manure and coffee drag treatments, and for Ca higher value among treatments was observed in the coffee drag treatment at the end and the lowest value at initiation. The results obtained in this study demonstrate the importance of the edaphic macrofauna to the vermicomposting process, since it allows more information about its influence on the continuity of soil organic matter decomposition processes.

Carbon and nitrogen molecular composition of soil organic matter fractions resistant to oxidation

Soil Research ◽  
2017 ◽  
Vol 55 (8) ◽  
pp. 809
Author(s):  
Katherine Heckman ◽  
Dorisel Torres ◽  
Christopher Swanston ◽  
Johannes Lehmann
Keyword(s):  
Molecular Structure ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Residence Time ◽  
Mean Residence Time ◽  
Chromic Acid ◽  
Soil Morphology ◽  
Fuel Type ◽  
Organic Residues ◽  
Photo Oxidation

The methods used to isolate and characterise pyrogenic organic carbon (PyC) from soils vary widely, and there is little agreement in the literature as to which method truly isolates the most chemically recalcitrant (inferred from oxidative resistance) and persistent (inferred from radiocarbon abundance) fraction of soil organic matter. In addition, the roles of fire, fuel type and soil morphology in the preservation of PyC are not yet defined. In an attempt to elucidate the importance of oxidative recalcitrance, fuel type and soil morphology to the persistence of soil organic matter, we examined two strongly contrasting soils using a variety of PyC isolation techniques coupled with quantifications of the molecular structure and mean residence time of the isolated organic materials. Surface and subsurface soil samples were examined from a Red Chromosol soil and a Black Vertosol soil. The δ13C values suggest that PyC in the Red Chromosol was sourced from eucalyptus, whereas PyC in the Black Vertosol was formed from grass. Soils were sieved at 53µm, treated with hydrofluoric acid to remove organics associated with mineral surfaces, then subjected to three common ‘PyC isolation’ treatments: chromic acid, photo-oxidation and chromic acid followed by photo-oxidation. Molecular structure of the organic residues remaining after each treatment was quantified by solid-state 13C cross polarisation magic angle spinning nuclear magnetic resonance and near edge X-ray absorption fine structure spectroscopy, and the mean residence time of the organic residues was estimated based on radiocarbon abundance. In all cases, treatment with chromic acid followed by photo-oxidation isolated the smallest proportion of organic matter (5–10% of <53µm C) which also had the longest mean residence time (estimated 600–3460 years). Additionally, molecular structure measurements indicated that this fraction was not composed solely of aromatic compounds, suggesting a non-homogenous source for the most oxidative-resistant fraction of soil organic matter.

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