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Impact of Anthropogenic Load on Rheological Properties of Typical Chernozems (Kursk Region, Russia) в коллективной монографии "Soil Degradation Advances in Geoecology 42" , editors Julia Krummelbein, Rainer Horn, Marcello Pagliaiкнига
- Авторы: Dolgor Khaydapova, Eugeny Milanovskiy, Eugeny Shein
- Год издания: 2013
- Издательство: CATENA Verlag
- Местоположение издательства: Germany
- Объём: 352 страниц (22,0 печатных листов)
- ISBN: 978-3-923381-59-3
- Тираж: 22 экз.
- Монография
- Аннотация: Impact of Anthropogenic Load on Rheological Properties of Typical Chernozems (Kursk region, Russia) D. Khaydapova, E. Milanovskiy, E. Shein Abstract Rheological approach provides the means for evaluation of interpartical interactions, micromechanical behavior, and fundamental information on soil structure deformations and its consequences. The top layer 0-10 cm of silty clay typical chernozems from native steppe, bare fallow soil, plowed twice a year since 1947 and oak forest of State Central Chernozem Reserve (Streletzkaya Steppe, Kursk, Russia) and from agricultural arable land and adjacent forest belt were used. Highest concentration of soil organic carbon (SOC) was detected in native steppe and the lowest - in bare fallow. The study of rheological behaviors of saturated soil pastes using distilled water were conducted on a modular compact rheometer (MCR 302, Anton Paar, Austria) at a constant temperature of 20oC, controlled by circular thermostat. Flow curve tests were conducted using coaxial cylinder measuring systems. This test procedure linearly ramps the shear rate from 0,16 to 300 s-1 and back and determines the resulting up- and down- shear stress curves. Shear stress at initially set shear rate close to zero (P1) shows the strength of structural bonds in the soil paste at the beginning of the experiment (bare fallow -60 Pa, arable land -77 Pa, forest belt -296 Pa, oak forest -320 Pa, native steppe – 873 Pa). In the first stress cycle yield points (Schramm, 1998) have been reached only in two soil sample pastes - bare fallow and plough. For the forest belt, oak forest and native steppe soils one stress cycle was not enough for complete destruction of structural bonds. Relation of viscosity at the end of experiment to viscosity at the beginning of experiment at the shear rates close to zero allows us to estimate the percentage of thixotropic structure restoration. Thixotropic structure restoration was highest in oak forest soil (79%), lowest in bare fallow (16%). This may be explained by the large share of silt and organic matter in the soils under oak forest. To estimate the reliability of established differences between soils, the obtained curves were approximated by power equation. Approximation parameters are the highest in native steppe and the lowest in bare fallow. Significant difference in structural conditions in plots under anthropogenic influence and virgin soils was found. Close correlation between SOC content and the strength of interparticle bonds was shown. Rheological approach was proven as a responsive and statistically reliable method to study soil properties behavior in quantitative terms, such as strength of interparticle bonds, percentage of thixotropic structure recover and detection of soil structure changes. Keywords: Rheology, shear stress, viscosity, soil structure, thixotropy
- Добавил в систему: Хайдапова Долгор Доржиевна
Прикрепленные файлы
| № | Имя | Описание | Имя файла | Размер | Добавлен |
|---|---|---|---|---|---|
| 1. | Полный текст | Khaydapova_Milanovskiy_Shein_Katena.pdf | 571,8 КБ | 2 сентября 2016 [milanovskiy] |