Due to the open-cast mining activities, a large area in the Lusatian region in eastern Germany was left unproductive. Robinia pseudoacacia L. was planted within different ages in that large area as a short rotation coppice for woody biomass cultivation as well as to increase soil nutrients by increasing plant phosphorous (P) availability, accumulating organic matter input and biological nitrogen fixation. In this experiment, soil chemical analysis has been done to investigate the improvement and status of P in the mining soil depending on the ages of plantation (16, 17, 18, and 27 years old) of Robinia pseudoacacia L. The results show a higher P sorption in the oldest site, and the average P sorption capacity (PSC) obtained in the oldest site was 21.0 mmol Kg(-1), which was 3-4 times higher than the youngest site. However, all the values were very low compared with the optimum plant growth level, and low P desorption indicates a low level of plant-available P in the soil. The lower sorption properties with the small amount of oxalate iron (Fe-ox) and oxalate aluminum (Al-ox) indicate the general P deficiency in the soil. However, a comparison from a previous study on the same experimental areas shows that not much improvement has occurred in soil P, and the change in soil P dynamics is very low. Nevertheless, the improvement of the values with increasing ages of Robinia pseudoacacia L. indicates that further improvement may be expected in soil nutrients with time.
