Long-Term Effects of Tillage on Soil Aggregates and the Distribution of Soil Organic Carbon, Total Nitrogen, and Other Nutrients in Aggregates on the Semi-Arid Loess Plateau, China
| Autor: | Ying Guo, Zhenfang Zhou, Guoxiao Wei, Huihui Dang, Yang Dong, Jinzhu Ma, Yibo Wang |
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| Rok vydání: | 2014 |
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| Zdroj: | Arid Land Research and Management. 28:291-310 |
| ISSN: | 1532-4990 1532-4982 |
| Popis: | Cultivating pasture changes the turnover of aggregates and aggregate-binding agents (soil organic carbon [SOC], total nitrogen [TN]), and affects soil nutrient levels. We tested the hypothesis that soil aggregate fractions and soil nutrient concentrations would exhibit temporal variation using a 55-year chronosequence of cultivated sites with silty clay loam soils on China's Loess Plateau. As cultivation duration increased, large aggregates (>1 mm) broke into smaller aggregates; the mean weight diameter (MWD) and geometric mean diameter (GMD) declined monoexponentially, reaching equilibrium after 32.9 and 35.5 years, respectively, in the surface soil and after 35.5 and 38.4 years in the subsurface soil. SOC and TN decreased over time following monoexponential curves; equilibrium concentrations for both occurred after 28.8 years in the surface soil versus 25.6 and 10.3 years, respectively, in the subsurface soil. The surface soil lost 170 and 7.6 kg ha-1 of SOC and TN, respectively, versus 45.6 and 6.7 kg ... |
| Databáze: | OpenAIRE |
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