| Autor: |
Behrendt, A., Mundel, G., Schalitz, G., Hölzel, D. |
| Předmět: |
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| Zdroj: |
Archives of Agronomy & Soil Science; Jan2001, Vol. 46 Issue 1/2, p73, 17p |
| Abstrakt: |
The influence of groundwater table to nutrient balances was investigated in long-term groundwater lyimeter experiments with few soils from North East Germany. High groundwater tables cause markedly higher evapotranspiration rates rather than deeper groundwater. The reasons are on the one hand an increase of evaporation, as capillarity is favoured by the immediate vivinity of water to the surface. on the other hand, the yield will usually increase with higher groundwater tables, which is additionally connected with an increase of transpiration. In the nitrogen balances it becomes obvious that deep drainage in fen soils increases the rate of leaching, which may be traced back to an oxidative peat mineralisation. The microbial mineralization of organic matter was analysed by CO{SUB2}-measurement. In fenland soils the annual carbon mineralization ranges between 286 to 669 gC/m[SUP2] (2,9...6, 7tC/ha) depending on level of ground water. Average groundwater levels(80-90 cm) caused the highest mineralization rates. The msot essential influence on potassium balances was provided by yielding. The extremely high extraction through the harvest on lower drainage of fen soils leads to high deficits in the total balance in spite of considerable supply through simulated groundwater. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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