Nutrient availability in the initial stages of surface mine spoil reclamation - Impact on plant growth

The aim of this study was to characterise nutrient availability in the init ial stages of reclamation and its impact on the growth of Secale multicaule L., the typical cover crop in newly established Pinus silvestris L. stands . A field experiment testing different levels of nutrient supply (N, P, K) was conducted on a carboniferous and a non-carboniferous sandy mine spoil r epresenting typical mine spoils in the open-cast lignite mining district of Lower Lusatia. On both types of mine spoils, primarily N and P limited pla nt growth. On non-carboniferous mine spoil, low P availability to plants wa s alleviated by mineral fertiliser application while on carboniferous mine spoil, due to P immobilisation, P availability was still limiting plant gro wth after similar levels of P fertilisation. The elevated N-min content in carboniferous mine spoil compared to non-carboniferous mine spoil is probab ly the result of less N leaching as the dominant N form in carboniferous mi ne spoil is NH4+ while the highly mobile NO3- is prevailing in the non-carb oniferous mine spoil. N release from geogenic organic matter in carbonifero us mine spoil as suggested by comparable N, contents in pedogenetically for med soil organic matter is less likely.