Bakacsi Z.,MTA Agrartudomanyi Kutatokozpont Talajtani es Agrokemiai Intezet |
Pasztor L.,MTA Agrartudomanyi Kutatokozpont Talajtani es Agrokemiai Intezet |
Szabo J.,MTA Agrartudomanyi Kutatokozpont Talajtani es Agrokemiai Intezet |
Ori N.,Debreceni Egyetem Agrar Es Gazdalkodastudomanyi |
And 2 more authors.
Agrokemia es Talajtan | Year: 2012
The work was focussed primarily on the comparative methodological analysis of the basic soil testing methods (plasticity index according to Arany, pH, hydrolytic acidity, carbonate, water-soluble total salt, and humus content) applied at the time of the Kreybig survey and recommended in current methodological manuals, in order to test the applicability and (if possible quantified) reliability of the data archived in the Digital Kreybig Soil Information System (DKSIS). A detailed investigation was also made of the parameters of the permanganate method once used to determine humus content and of the Tyurin method that later replaced it. The results obtained with the two methods were compared in a series of ten soil samples originating from the Bodrogköz region of Hungary. Deviations between the old and new methods used to determine particle size distribution and exchangeable cations were also summarized. The following conclusions were drawn: It is clear from the descriptions that sampling and soil sample processing were carried out as they are today. The determination of Arany's plasticity index involved manual mixing, which is still used today for small sample numbers, though mechanical mixing is applied for larger sample series, generally resulting in lower values than in the case of manual mixing in the case of heavy soils. The pH values were recorded using the electrometric technique, as they are today, and measurements of carbonate content and hydrolytic acidity were also based on the same principles and techniques. The results are thus totally compatible with modern data. It was found that a uniform conversion factor could not be determined for the humus content data obtained with the permanganate and Tyurin methods, as the results were not independent of the mechanical composition of the soil samples. In the case of clay and loam samples, bichromate digestion gave 1-10% higher values, while for sandy soils the results obtained with the permanganate method were almost 15% higher. Due to changes in the methods used to determine particle size distribution and exchangeable cations, the earlier results only have informative value.