Research on the effectiveness of amending composite ameliorants for remediating covering soil on the waste slag dump
It is highly important to quickly and efficiently remediate waste slag dump for project construction for protecting surrounding ecological environment.In this study,a pot experiment was conducted to investigate the effects of amendment of three types of composite ameliorants,including biochar+organic fertilizer(BF),biochar+organic fertilizer+calcium bentonite(BF-C)and biochar+organic fertilizer+polyacrylamide(BF-P),on the stability of soil aggregates,soil fertility and plant(Cynodon dactylon)growth on the waste slag dump constructed for water diversion project in central Yunnan,China,and then obtain the preferable ameliorant for rapid green restoration of project waste slag dumps.The results showed that the BF treatment significantly reduced the bulk density and increased nutrient contents in the soil covering on waste dump as compared to the control without ameliorant amendment,and amendment of polyacrylamide(PAM)together further enhanced the effectiveness.Amendment of composite ameliorants increased the content of≥0.25 mm aggregate in the soil and enhanced the stability of soil aggregates,with the notable enhancement efficiency achieved by PAM amendment.BF-C and BF-P treatments effectively increased the activities of enzymes related to matter conversions in the soil covering on waste dump.Furthermore,BF and BF-P treatments remarkably increased the biomass of Cynodon dactylon.The results of data analysis showed that there were significant correlations among the bulk density,pH,contents of organic matter and nutrients,enzyme activities and stability of aggregates in the soil covering on waste dump under ameliorant amendment.The improvement efficiency for various soil properties after ameliorant amendment was comprehensively evaluated based on the membership function method,and the comprehensive efficacy of different treatments ranked as:BF-P>BF-C>BF>CK.The results of this study indicated that the combined application of biochar,organic fertilizer and PAM can comprehensively and effectively improve the quality and structure of the soil covering on waste dump,and this method has high potential for rapid green restoration and improvement of water and soil stability of project waste slag dumps.
Covering soil on waste dumpcomposite ameliorantsoil fertilityaggregate stability
万方数据
维普
