Background It is necessary to carry out vegetation restoration through manual intervention in open-pit coal mine dumps of arid areas, while vegetation, soil water, temperature and nutrient are important indicators to evaluate the effectiveness of restoration. Therefore, the changes of above indicators under different remediation modes are analyzed to provide reference for vegetation restoration in open-pit coal mine dump.

Methods Five modes of ecological bag block (C-S), honeycomb lattice room full cover (C-F), vegetation blanket cover (J-C), vegetation blanket cover + ecological bag block (J-S) and vegetation blanket cover + honeycomb lattice room full cover (J-F) were set in Rujigou open-pit coal mine dump, CK was the plot with only grass seeds sowed without any renediation and vegetation, soil water, temperature and nutrient under above remediation modes were compared by one-way ANOVA analysis.

Results 1) The vegetation coverage under CK, C-S, C-F, J-C, J-S and J-F were 0, 0, 0, 10.00%, 19.67%, and 16.33% respectively, and the vegetation coverage under J-S was significantly higher than that under other modes (P < 0.05). Plant height was mainly related to plant species, and the height of Halogeton glomeratus, Agropyron desertorum and Lespedeza bicolor were nearly 20.0, 3.5 and 4.0 cm respectively. The growth of H. glomeratus and L. bicolor was good, while that growth of A. desertorum was poor. 2) During the observation period, the soil water content under C-S, C-F, J-C, J-S and J-F were 3.12%, 3.86%, 5.88%, 6.66% and 5.98% higher than that under CK, respectively. The average soil temperature under J-C, J-S and J-F decreased by 2.10, 2.68 and 1.95 ℃, and the daily soil temperature differences decreased significantly by 1.64, 1.37 and 1.54 ℃ (P < 0.05). The changes of soil pH and organic matter content were slight under different modes, while the contents of soil hydrolyzable nitrogen and available phosphorus were significantly lower than those under CK (P < 0.05). The soil total nitrogen content under J-C, J-S and J-F increased by 8.11%, 10.81% and 8.11%, and soil available potassium content increased by 54.22%, 38.36% and 64.97%.

Conclusions There are differences in vegetation coverage, soil water, temperature and nutrient under different repair modes. The effectiveness of repair modes for vegetation restoration are not ideal, mainly related to poor water and nutrient condition of test dump. The change of vegetation coverage, soil water content, total nitrogen and available potassium content are significant under J-C, J-S and J-F, and the vegetation coverage under J-S increases the most among designed repair modes.