Evaluation of Soil Quality and Maize Growth in Different Profiles of Coal Gangue Filling Reclaimed Land
land reclamation; soil properties; soil quality index; maize growth
（2）环境科学与工程 > 3. 土地复垦与生态修复
摘要录用
Shuguang Liu / 中国矿业大学
Zhenqi Hu / 中国矿业大学
Utilizing coal gangue (CG) as a filling matrix to construct different profiles of reclaimed land in coal mining subsidence has problems of lack of water and fertilizer and low crop yield. To clarify the influence of profile structure on surface soil water and fertilizer and the optimal profile, 7 different profiles of reclaimed land were constructed in the field with maize planting experiments to systematically assess soil quality of reclaimed land, select soil profile, and verify factors affecting crop agronomic characteristics. Soil quality was evaluated by the minimum data set (MDS) of soil quality index (SQI) obtained by principal component analysis (PCA), the correlation between corn agronomic characteristics and soil physical and chemical properties was computed. The result shows that soil organic matter (SOM) and soil moisture (SM), pH value, and electrical conductivity (EC) were the critical indicators to evaluate soil quality of reclaimed farmland, pH contributed the highest value in the surface SQI. The surface SQI value increased from increase in the thickness of surface overburdens, and decreased from increase in the interlayer depth of reclaimed profiles filling with CG. R2 between the SQI based on MDS and annual crop yield is 0.438. Agronomic traits of maize, except stem diameter, are positively correlated with the nutrient index and SM of the surface soil, and negatively correlated with pH, EC and total salt content (TS). This study indicates that it is necessary to take effective measures to reduce and control pH value of CG used as a substrate for filling and reclamation. Choosing a thicker surface overburden can effectively increase soil quality and harvest. Meanwhile, the inherent characteristics of the surface and interlayer soil are supposed to be considered in the design of the reclaimed profile type.