Research on the use of compost for the reclamation of post mining landscapes
About this good practice
The open-pit mining of lignite coal in Brandenburg claimed approximately 910 km² of land. In the aftermath of mining, the rehabilitation of 600 km² of land for further agricultural or forestry use is challenging, as mine soils initially lack organic matter and nutrients. The anthropogenic formation of the post-mining soils and their sandy texture further result in weak biological, chemical, and physical soil properties. In order to improve these soil functions, the application of compost from biowaste was investigated. Therefore, pot experiments, lysimeter studies, and field studies were conducted, applying different amounts of compost.
Soil organic matter content, nutrient supply, plant-available water, and cation exchange capacity increased with increasing amounts of applied compost. Since plant growth also increased, the formation of leachate decreased significantly, resulting in a reduction of nutrient leaching. When applying high amounts, it is important that the compost does not contain high levels of contaminants. If threshold values of the German Bio-waste Ordinance for contaminants in compost and precautionary values of the German Soil Protection Ordinance are met, negative impacts on soils, plants, and groundwater are not to be expected. The applied amount of compost has to be adapted to the nutrient demand of plants.
The operators of open-pit mines, foresters, and farmers can benefit from such measures, as land becomes arable faster when applying compost.
Resources needed
The investigation is cost-intensive and time-consuming. It was funded by the Federal Ministry of Education and Research (BMBF).
Evidence of success
The results of the study led to guidelines for the application of compost in rehabilitation and agricultural practice. The use of compost showed advantages compared to the use of mineral fertilizers. Compost contributes to the better formation of a stable upper soil layer with improved water retention capacity and good soil stability. Public presentations of the project to stakeholders contributed to improvements in soil management and the implementation of compost for remediation measures.
Potential for learning or transfer
Devastated areas are widespread across Europe. Not only mining areas are affected; areas impacted by desertification may also benefit from soil remediation and improvement through compost application. Furthermore, applying compost on such land may promote its use as a fertilizer on additional agricultural land, benefiting from the experiences learned from devastated areas.
An increased demand for compost may also support the introduction of separate collection of biowaste and its processing.
Further information
Website
Good practice owner
You can contact the good practice owner below for more detailed information.
Forschungsinstitut für Bergbaufolgelandschaften e.V.