Wind erosion after steppe conversion in Kazakhstan

verfasst von: Moritz Koza, Roger Funk, Julia Pöhlitz, Christopher Conrad, Olga Shibistova, Tobias Meinel, Kanat Akshalov, Gerd Schmidt
Abstract: Semi-arid regions of Central Asia suffer from wind erosion due to expanding steppe conversion and unsustainable farming practices. Empirical data from field observations are needed to support the implementation of adapted management. In this study, a mobile wind tunnel was used for the first time in Kazakhstan to assess the soil's erodibility under real conditions. Field experiments were conducted on loamy sands with different initial conditions that are typical for the most erosive time of the year: a bare surface with a cloddy structure after recent steppe conversion, a weak crust on a plot with barley (Hordeum vulgare L.), and a plot with loose material in the rows of maize plants (Zea mays L.). Subsequently, different levels of mechanical stress (low, moderate, high) were considered to analyze the effect of disruptive forces soils experience during field cultivation (light cultivator, disc harrow, tractor tires) on possible soil losses. The results of wind tunnel experiments showed already great differences under initial conditions. The cloddy structure of the recent steppe conservation had the lowest susceptibility against wind erosion due to a good aggregation and a large roughness, resulting in soil loss of 12 g m⁻². The plot grown with barley was less affected by wind erosion due to the weak crust, smaller distances between plants, and leaves close to the ground (soil loss of 34 g m⁻²). Maize was also the most problematic crop in the study area because wind can blow below the plant canopy without considerable resistance during the early growth stages. Additionally, existing deposits in the maize rows from previous erosion events led to the highest soil loss of 1609 g m⁻². Mechanical stress by seedbed preparation generally increased the erodible fraction, resulting in higher soil losses (light cultivator: 198 ± 129 g m⁻², disc harrow: 388 ± 258 g m⁻²). The most severe disruption of soil structure occurred on tractor tire tracks, causing a loss of 2767 ± 1810 g m⁻². Consequently, the pulverizing effect of tractor tires on dry soil must be considered a serious emission source. Comparing the soil organic carbon content of topsoil and eroded material showed that organic carbon was enriched only in the aeolian sediments of the recently converted plot (+69%). We conclude that soils after steppe conversion need to be treated with particular care from the very beginning so that severe events from the past are not repeated.
Organisationseinheit(en): Institut für Bodenkunde
Externe Organisation(en): Martin-Luther-Universität Halle-Wittenberg
Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.
Amazonen-Werke H. Dryer GmbH & Co. KG
Barayev Research and Production Center for Grain Farming
Typ: Artikel
Journal: Soil and Tillage Research
Band: 236
Anzahl der Seiten: 16
ISSN: 0167-1987
Publikationsdatum: 02.2024
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Agronomie und Nutzpflanzenwissenschaften, Bodenkunde, Erdoberflächenprozesse
Elektronische Version(en): https://doi.org/10.1016/j.still.2023.105941 (Zugang: Offen)

BibTeX

@article{8e8d5fc212424e8391715180f9dfedfc,
title = "Wind erosion after steppe conversion in Kazakhstan",
abstract = "Semi-arid regions of Central Asia suffer from wind erosion due to expanding steppe conversion and unsustainable farming practices. Empirical data from field observations are needed to support the implementation of adapted management. In this study, a mobile wind tunnel was used for the first time in Kazakhstan to assess the soil's erodibility under real conditions. Field experiments were conducted on loamy sands with different initial conditions that are typical for the most erosive time of the year: a bare surface with a cloddy structure after recent steppe conversion, a weak crust on a plot with barley (Hordeum vulgare L.), and a plot with loose material in the rows of maize plants (Zea mays L.). Subsequently, different levels of mechanical stress (low, moderate, high) were considered to analyze the effect of disruptive forces soils experience during field cultivation (light cultivator, disc harrow, tractor tires) on possible soil losses. The results of wind tunnel experiments showed already great differences under initial conditions. The cloddy structure of the recent steppe conservation had the lowest susceptibility against wind erosion due to a good aggregation and a large roughness, resulting in soil loss of 12 g m−2. The plot grown with barley was less affected by wind erosion due to the weak crust, smaller distances between plants, and leaves close to the ground (soil loss of 34 g m−2). Maize was also the most problematic crop in the study area because wind can blow below the plant canopy without considerable resistance during the early growth stages. Additionally, existing deposits in the maize rows from previous erosion events led to the highest soil loss of 1609 g m−2. Mechanical stress by seedbed preparation generally increased the erodible fraction, resulting in higher soil losses (light cultivator: 198 ± 129 g m−2, disc harrow: 388 ± 258 g m−2). The most severe disruption of soil structure occurred on tractor tire tracks, causing a loss of 2767 ± 1810 g m−2. Consequently, the pulverizing effect of tractor tires on dry soil must be considered a serious emission source. Comparing the soil organic carbon content of topsoil and eroded material showed that organic carbon was enriched only in the aeolian sediments of the recently converted plot (+69%). We conclude that soils after steppe conversion need to be treated with particular care from the very beginning so that severe events from the past are not repeated.",
keywords = "On-farm experimentation, Particle size distribution, Soil loss, Soil management, Soil organic carbon, Wind tunnel",
author = "Moritz Koza and Roger Funk and Julia P{\"o}hlitz and Christopher Conrad and Olga Shibistova and Tobias Meinel and Kanat Akshalov and Gerd Schmidt",
note = "Funding Information: This study was supported by the German Federal Ministry of Education and Research (BMBF) by funding the research project: Innovative Solutions for Sustainable Agricultural and Climate Adaptation in the Dry Steppes of Kazakhstan and Southwestern Siberia ( ReKKS ) – grant number 01LZ1704B . ",
year = "2024",
month = feb,
doi = "10.1016/j.still.2023.105941",
language = "English",
volume = "236",
journal = "Soil and Tillage Research",
issn = "0167-1987",
publisher = "Elsevier",
}