Effects of Brown Coal Application on Heavy Metal Uptake by Plants

Abstract

In the field experiments carried out in 2000 and 2001 at the Nagyhörcsök Experimental Station on calcareous chernozem soil contaminated with heavy metals the results show that the application of 40 t/ha Balinka brown coal did not decrease the uptake of essential elements by the maize, barley and rape test plants, and did not decrease the fertility of soil. There was no change or sometimes a slight increase in the investigated tissues of the plants due to the effect of coal application. This is advantageous in Zn deficient soils, but on similar soils strongly polluted with Zn the Balinka brown coal cannot be used as an effective remediator. The coal treatment drastically decreased the Se toxicity of the soil, the maxi-mum yield could even be obtained on the strongly Se-polluted plots. The development of plant stands in the coal treated plots improved considerably, perhaps due to the better moisture regime conditions of the soil. The Sr and Cd content in plant tissues decreased in several cases due to brown coal application. The most dangerous contaminant, the Cd concentration in the plants dropped to half or even 1/3, as a result of coal treatment. The results of the two-year experiments showed that the 40 t/ha rate of Balinka brown coal can be used successfully and economically in the in situ remediation of Cd, Se and Sr contaminated soils. This rate does not influence the original fertility parameters of the soil, but can be applied with advantages both in extremely light- or heavy textured soils in case of moderate contamination. However, further investigations are needed to find out the effects of Balinka-type brown coal application on other soil types, plants and other polluting elements.