<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The formation of soil aggregates, including water-stable aggregates, is linked to soil organic matter (SOM). Biochar (B) is carbon-rich, which, in addition to storing carbon in a stable form for many years, has important benefits for soils and plants, but the mechanisms of soil structure formation after B and mineral fertiliser application are not sufficiently studied. For this reason, the study aimed to answer the following questions: How (1) the rate of B and (2) varying levels of nitrogen fertiliser (N) being applied to the soil affect the dynamics of soil aggregation due to the increase in the content of soil organic carbon, labile carbon in the bulk soil and in the content of water-stable aggregates (WSA) size-fractions. In 2014–2021, in Dolná Malanta (experimental site of Slovak University of Agriculture on silty loam Haplic Luvisol) during the growing seasons, soil samples were collected from all the B (0, 10 and 20 t ha–1) and N (0, 1<sup>st</sup> and 2nd level of N fertilisation) treatments. The results have shown that the highest values of many variables were associated with B20 treatment for all the N fertilisation levels. B compared to N more significantly affected the content of almost all the size-fractions of WSA. In all the treatments, the content of WSAma >5 mm, 5–3 mm, 3–2 mm and 1–0.5 mm in size was increasing over time – a yearly increase from 0.31 to 2.14% for 8-years. Based on the changes in the SOM content, WSA were divided into 3 groups: 1) Water-stable microaggregates (WSAmi &lt; 0.25 mm), 2) Smaller size-fractions of water-stable macroaggregates (WSAma 1–0.25 mm), and 3) Medium and large fractions of WSAma (WSAma ≥1 mm).</p>
</abstract>

The formation of soil aggregates, including water-stable aggregates, is linked to soil organic matter (SOM). Biochar (B) is carbon-rich, which, in addition to storing carbon in a stable form for many years, has important benefits for soils and plants, but the mechanisms of soil structure formation after B and mineral fertiliser application are not sufficiently studied. For this reason, the study aimed to answer the following questions: How (1) the rate of B and (2) varying levels of nitrogen fertiliser (N) being applied to the soil affect the dynamics of soil aggregation due to the increase in the content of soil organic carbon, labile carbon in the bulk soil and in the content of water-stable aggregates (WSA) size-fractions. In 2014–2021, in Dolná Malanta (experimental site of Slovak University of Agriculture on silty loam Haplic Luvisol) during the growing seasons, soil samples were collected from all the B (0, 10 and 20 t ha–1) and N (0, 1st and 2nd level of N fertilisation) treatments. The results have shown that the highest values of many variables were associated with B20 treatment for all the N fertilisation levels. B compared to N more significantly affected the content of almost all the size-fractions of WSA. In all the treatments, the content of WSAma >5 mm, 5–3 mm, 3–2 mm and 1–0.5 mm in size was increasing over time – a yearly increase from 0.31 to 2.14% for 8-years. Based on the changes in the SOM content, WSA were divided into 3 groups: 1) Water-stable microaggregates (WSAmi < 0.25 mm), 2) Smaller size-fractions of water-stable macroaggregates (WSAma 1–0.25 mm), and 3) Medium and large fractions of WSAma (WSAma ≥1 mm).

Managing soil organic matter through biochar application and varying levels of N fertilisation increases the rate of water-stable aggregates formation

Department of Soil Science, Institute of Agronomic Sciences, Faculty of Agrobiology and Food Resources

Department of Biometry, Institute of Agriculture

Warsaw University of Life Sciences – SGGW

Department of Soil Physics, Physical Chemistry and Biophysics

Journal of Hydrology and Hydromechanics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The formation of soil aggregates, including water-stable aggregates, is linked to soil organic matter (SOM). Biochar (B) is carbon-rich, which, in addition to...

Managing soil organic matter through biochar application and varying levels of N fertilisation increases the rate of water-stable aggregates formation

Published Online: May 14, 2023

Page range: 199 - 209

Received: Nov 25, 2022

Accepted: Feb 10, 2023

DOI: https://doi.org/10.2478/johh-2023-0004

Keywords
Soil structure, Water-stable aggregates, Biochar, Fertilisation

© 2023 Vladimír Šimanský et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Managing soil organic matter through biochar application and varying levels of N fertilisation increases the rate of water-stable aggregates formation

Published Online: May 14, 2023

Page range: 199 - 209

Received: Nov 25, 2022

Accepted: Feb 10, 2023

DOI: https://doi.org/10.2478/johh-2023-0004

KeywordsSoil structure, Water-stable aggregates, Biochar, Fertilisation

© 2023 Vladimír Šimanský et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
Soil structure, Water-stable aggregates, Biochar, Fertilisation