Amelioration and reforestation of sulfurous mine soils in Lusatia (Eastern Germany)

In Germany nearly 1.550 km² have been claimed by brown coal mining until now. Mine soils formed of carboniferous and sulfurous overburden are classified as “sulfurous mine soils”. They remain vegetation-free for decades and may be cultivated only after soil amelioration. The objective of amelioration is a sustained improvement of soil reaction. Lime requirement for the achievement of a certain pH-value is calculated from acid-base-balance (SBB). Lime fertilizers and base-rich brown coal ashes are used for amelioration. As ashes have serveral advantages,their application is recommended. The ameliorative application of lime fertilizer or brown coal ash should be incorporated intensively into the soil to a depth of 60 cm, better 100 cm. Amelioration includes a mineral fertilization with N, P and K. Afforestations with Pinus sylvestris, Pinus nigra, Larix decidua, Larix eurolepis, Tilia cordata, Quercus rubra and Quercus petraea on ameliorated mine soils show surprising good results. Multi-species stands have very positive effects on soil formation. Raw humus is formed under pine and larch, and under deciduous trees moder and mull with higher bioactivity and better development of water and nutrient balance in the topsoil are found.     

Water and Element Fluxes of Red Oak Ecosystems during Stand Development on Post-Mining Sites (Lusatian Lignite District)

Most spoils in the Lusatian lignite district have been afforested successfully. However, since soil chemical status remains very different compared to unmined locations even after decades it is still unclear if forest ecosystems develop to a self-sustainable status or if restoration will fail in the long term. To clarify this question water and element fluxes of different-aged red oak(Q. rubra L.) stands on both Quaternary pure sands and Tertiary, pyritic loamy sands were investigated and compared to a nearby, unmined location. Due to increasing interception and evapotranspiration, the deep percolation rates of red oak forests decline drastically within30 yr. Annual groundwater recharge is about 300 mm yr^-1(41–46% of precipitation) initially. Deep percolation of the older stands decrease to less than 15% of precipitation, independent of substrate type. Tertiary substrates are characterized by intensive leaching of H, Fe, Al, Mg, Ca, NH₄-N and SO₄-S due to pyrite oxidation and therefore enhanced silicate weathering. Despite of drastically declining output rates with progressing ecosystem development, they remain remarkably higher as compared to Quaternary sands. However, despite differences in soil chemistry, the aged stands act as an almost complete sink for N, P and K. Compared to adjacent oak forests on undisturbed soils the stands on reclamation sites show very similar patterns with regard to N, P, K, Ca and Mg turnover.     

Kennwerte und Eigenschaften der auf Braunkohlenbasis durch oxidative Ammonolyse hergestellten Humusdüngestoffe

Der auf Braunkohlenbasis durch oxidative Ammonolyse hergestellte Humusdüngestoff wird anhand seiner Standardparameter, Elementgehalte und chemischen Eigenschaften beschrieben. Hiernach ist die N-modifizierte Braunkohle ein schadstoffarmes, N-reiches, dauerhumusähnliches Bodenverbesserungsmittel, das als Granulat sehr lagerungsbeständig ist. Der neue Humusdüngestoff enthält stabil 5,78 ± 0,38% Gesamtstickstoff, der chemisch unterschiedlich gebunden ist. Aufgrund seiner vergleichsweise geringen N_min-Gehalte kann er in größeren Mengen zur nachhaltigen Verbesserung der KAK_pot und N_t-Bodenvorräte humusfreier und kolloidarmer Kippenböden eingesetzt werden.     

Auswirkungen der durch oxidative Ammonolyse chemisch veränderten Braunkohle auf die Bodenbiologie

In Langzeit-Inkubationsversuchen wurden die Auswirkungen abgestufter Mengen von chemisch veränderter (N-modifizierter) Braunkohle auf die mikrobiologischen und enzymatischen Unsatzleistungen in verschiedenen Kippsubstraten geprüft. Die Untersuchungsbefunde charakterisieren diesen Humusdüngestoff als ein dauerhaft wirksames organisches Bodenverbesserungsmittel mit N-Düngewirkung, das die bodenmikrobiologischen Aktivitäten verbessert.     

Pot and field experiments on the suitability of lignite as soil improving agent

Effects of raw brown coal ("Kohletrübe"), brown coal modified with ammonia water, NH3, ("Ammonkohle") and composted brown coal ("Biomineraldünger") on plant yield and on selected soil fertility characteristics of a colloidpoor and a coal-bearing dump soil are tested in a pot and field experiment. The results confirm already published results. Therefore chemical modified nitrogen enriched brown coal is a humus fertilizer the influence of which sustained the water and nutrient storing capacity as well as the nutrient transformation ability of colloid-poor dump soils. Soil improving and yield increasing effects of coal fertilisation depend on particular conditions.     

Freilandversuche zur eignung chemisch veränderter weichbraunkohle als bodenverbesserungsmittel bei der landwirtschaftlichen rekultivierung humusfreier kippenböden 1 : Field experiments with n-modified brown coal as humus fertilizer in agricultural revitalisation of humus free dump soils

Die bodenmeliorativen und ertragssteigernden Effekte des Einsatzes von N-modifizierter Weichbraunkohle als Humusdüngestoff bei der landwirtschaftlichen Rekultivierung humusfreier Kippenböden werden in mehreren Freilandversuchen überprüft. In diesem Beitrag wird über die zu Rekultivierungsbeginn mit W.-Roggen, W.-Weizen, Kartoffeln und Luzerne erzielten Ergebnisse berichtet.