216 research outputs found
Density-based fractionation of soil organic matter: effects of heavy liquid and heavy fraction washing
Physical fractionation methods used in soil organic matter (SOM) research commonly include density-based procedures with heavy liquids to separate SOM pools with varying turnover rates and functions. Once separated, the heavy SOM pools are often thoroughly rinsed with water to wash off any residues of the heavy liquids. Using four soils with contrasting properties, we investigated the effects of using either sodium polytungstate (SPT) or sodium iodide (NaI), two of the most commonly used heavy liquids, on the distribution of organic carbon (C) and total nitrogen (N) in free light, intra-aggregate light, and mineral-associated heavy SOM pools isolated by a common fractionation scheme. We also determined the effects of washing the mineral-associated heavy SOM fractions on the recovery of organic C and total N after separation. Because of its smaller viscosity compared to that of NaI, SPT consistently yielded greater intra-aggregate and smaller mineral-associated soil organic C contents. We also confirm that some commercial SPT products, such as the one used here, can contaminate organo-mineral heavy pools with N during density-based fractionation procedures. We do not recommend the repeated washing of heavy fractions separated with Na-based heavy liquids, as this can mobilize SOM
Pulse polarographic determination of thiophanate methyl fungicide in relation to its soil adsorption study
La simulazione del destino ambientale dei fitofarmaci: i modelli matematici per la previsione del movimento nel terreno
Effetto dell’uso del sistema buffer strips sul ruscellamento dei fitofarmaci
CD a cura di C. Vischetti e A. Esposit
Aspetti chimico-agrari dell’agricoltura biologica: fitofarmaci, tossine e composti di origine vegetale
Validazione dei modelli matematici per la previsione del destino dei fitofarmaci nel suolo: situazione italiana
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