Causes clarification of the soil aggregates stability on mulched soil

Abstract

Soil aggregates have great effects on soil properties and soil functions. Mulching (organic inputs) has been known as a factor influencing soil aggregate stability. Our study aimed to reveal the causes of the higher stability of soil aggregates under organic mulches. The primary soil characteristics such as organic carbon (Cox), humus quality (E4/E6), potential wettability index (PWI), and aromaticity index (iAR) were determined. The Cox was measured using rapid dichromate oxidation, and E4/E6 was measured using the UV-Vis spectrophotometry. The PWI and iAR were determined according to the intensity of selected bands in diffuse reflectance infrared spectra. Results showed that mulched plots contained higher Cox content in aggregates in comparison with whole soil. This indicates that the carbon was stabilized within the aggregates and sequestrated into the soil. The iAR was significantly higher after using the organic mulches, the aliphatic components of the organic matter thus contribute more to the aggregates stabilization. The PWI of aggregates was found to be higher after applying these mulches than in soil. Organic mulches are therefore able to reduce the wettability of the aggregates and also to protect the aggregate from dispersion with water.

The Influence of Organic and Mineral Fertilizers on the Quality of Soil Organic Matter and Glomalin Content

“…If performed correctly, this method is capable of producing very good results characterizing soil organic matter. Our study's results agree with Thai et al [55] and demonstrate that the E4/E6 method is unfit for the determination of soil organic matter quality, and was therefore not used in further evaluations.…”

“…A significant correlation between EEG and PWI (0.735, p < 0.01) is in accordance with this hypothesis. The aromaticity index (IAR) also expresses the stability of soil organic matter [55]. Treatments with organic fertilizers produce significantly higher values.…”

How various mulch materials can affect the soil hydro-physical properties

“…This indicates that the immediate impact of various mulches on soil pH, which resulted in high differences between the values from different scenarios (Pavlů et al, 2021), diminished. The reason in both cases can be a gradual decomposition of all mulches and leaching of the selected compounds towards groundwater that resulted in different composition of aggregate's cementing agents in time (Thai et al, 2022). The EC values in Table 1 (which were not measured in our previous study) showed that the salinity under organic mulches (particularly under WCH cover) was much larger than that for the control plots (NMU) and the CRS plots.…”

“…Wood chips or gravels are preferred in gardening. Different materials then have different effects on soil water and thermic regimes, and consequently also on other soil properties (e.g., Al-Shammary et al, 2020;Hlaváčiková et al 2019;Kader et al, 2017;Kasirajan and Ngouajio, 2012;Kodešová et al, 2014;Pavlů et al, 2021;Qu et al, 2019;Thai et al, 2022;Wang et al, 2021;Yang et al, 2020). For instance, Pavlů et al (2021) studied soil properties in 27 perennial patches covered by eight different mulch materials (bark chips, wood chips, wheat straw, cardboard, paper foil, decomposable matting, nonwoven fabric covered by bark chips, and crushed basalt) and control patches without any mulch during the 4-year period.…”

Temporal changes in soil chemical compositions in acidified mountain forest soils of Czech Republic

“…It was contrast to the finding of Ohno et al (2014) where the abundance of condensed aromaticity of SOM was much lower in subsoil under coniferous and deciduous forests due to the adsorption of aromatic compounds to the minerals present in the soil profiles. The decrease or increase of the iAR through the soil profile, generally, depends on the association of plant residue compositions, climate conditions, and microorganism present in the soil (Koutika et al 2020;Thai et al 2022). The lower aromaticity in the uppermost soil layer than in the deeper soil profile under both forest tree species, however, was indicated by the less humified and decomposed organic matter due to the chemical and physical interaction mechanisms (Chen et al 2013;Corvasce et al 2006).…”