Cover Crop Residue Effects on Soil and Corn Performance in Ex-Nickel Mining Soils.

<b>Background and Objective:</b> The use of cover crop residue for improving soil quality has been widely applied. Nevertheless, the effectiveness for improving ex-mining soil quality and crop performance at ex-mining soils is rarely documented. This study investigated the effect of cover crop residue on soil quality enhancement and corn production established in ex-nickel mining soils. <b>Materials and Methods:</b> An experiment comprising three treatment of cover crops residue, including <i>Eleusine indica, Centrosema pubescens</i> and <i>Calopogonium mucunoides</i>, arranged in a completely randomized design with three replications. The soil improvement process was evaluated by several parameters, such as soil acidity, soil organic carbon, total nitrogen, exchangeable potassium, exchangeable magnesium and heavy metals. On the other side, corn's growth performance was assessed using some attributes, i.e. height, diameter, total leaves, leaf area and biomass accumulation. <b>Results:</b> The results demonstrated that the cover crops residue had the potential to improve ex-nickel mining soil quality. The highest soil improvement was recorded in total nitrogen (700-800%). The treatments also showed a positive advantage to reduce heavy metals content, particularly for Fe, Mn and Zn by approximately 51.58-85.74%. No significant difference in corn growth performance was found in this study (p>0.05). However, the utilization of crop residue from <i>Calopogonium mucunoides </i>exhibited relatively higher total biomass than other treatments by around 3.08±1.99 g plant¹. <b>Conclusion:</b> Despite the treatments had no significant effect on corn performance. This study realized that cover crop residue could improve soil conditions for providing better environmental conditions for agriculture development.