Total organic c and its decomposable part in arable soils in the Czech Republic

Abstract

Total soil organic matter and its decomposable part have been studied in arable farm fields in the Czech Republic. One hundred and forty localities have been selected. Besides the soil types and subtypes (taxonomical soil units), textural units, total organic carbon content, and even geographical distribution was taken into account. Soil samples have been taken from the top soil (0 -20 cm) at the selected sites and a number of analyses were carried out. Organic C content in the top soil from the selected 140 sites on arable soils ranged between 1% and 2% in more than 80% of the soil samples. C/N ratio oscillated around 10 in a rather narrow band. There were no remarkable changes in the organic C content in the top soil in 82 sites over the last decade (1992 to 2002). The distribution of the organic C content in the soil samples according to the taxonomical soil units have shown the lowest values in the Haplic Luvisols and Albeluvisols. Their variability was relatively low. In Cambisols, on the contrary, the average C content values were higher but their variability was also much higher than in Luvisols. The decomposable organic C content closely correlated with the total organic C content. The lowest decomposable C contents were found in the soil samples from Luvisols, probably due to the favourable conditions for microbial activities and organic matter turnover. Hot water soluble C accounted for about 3 -4% of the total organic C content and, apparently, its content increases with the increasing total organic C content. There were highly significant correlation coefficients between most of the selected criteria.

The changes of soil nitrogen and carbon contents in a long-term field experiment under different systems of nitrogen fertilization

“…These results confirmed higher mineralization of the organic matter in the Cambisol. Similar results were published by Kubát et al (2004) who investigated contents of total and decomposable carbon in more than 140 localities in the Czech Republic. Table 6 clearly shows that hot water extraction is a stronger extraction method compared to the 0.01M CaCl 2 extraction.…”

The State of the Soil Organic Matter and Nutrients in the Long-Term Field Experiments with Application of Organic and Mineral Fertilizers in Different Soil-Climate Conditions in the View of Expecting Climate Change

“…Deterioration of natural sources quality is leading to a negative influence on soil quality (degradation), which agricultural activity depends on. This is also evident in the Czech Republic during the past 25 years [27]. Soil quality deterioration is primarily caused by four major factors: (a) Changes in the structure of cultivated crops and crop rotations (reduction of the share of perennial fodder crops (alfalfa, clover [index 1990 [29] and Ren et al [30] quoted that decreasing application of manures and organic fertilizers influenced not only stable organic compounds but also soil microorganisms and nutrients regimes.…”

Assessment of Retention Potential and Soil Organic Carbon Density of Agriculturally used Chernozems, Cambisols and Fluvisols

“…Soil pH was measured in 1M of KCl (ISO 10390, 2005). The C ox (oxidizable carbon) was determined by means of oxidation using chromosulphuric mixture (ISO 14235,1998) to characterize SOC (Kubát et al, 2004).…”