Simulation on reliefing negative influence of damage roots on growth of maize by application of arbuscular mycorrhizal fungi

Abstract: With the first coal output and larger subsidence area in China, the Shendong mining area is the largest coal field in China and one of the seven major coalfields in the world now. Underground mining would cause ground subsidence damage and large amounts of cracks, which would result a loss of surface moisture and nutrient and intensifying drought. There are a few reports about damage to plant roots caused by coal mining at home and abroad. The main reasons are that plant roots in soil would form a "black box" which is difficult to observe. In addition, the irregular distribution of plant roots in soil and the different forces generated in process of surface subsidence are difficult to study comprehensively. The technologies to repair damaged plant roots have not been completely perfected yet. Although the physical methods and chemical methods would alleviate the adverse effects of coal mining to some extent, they can not fundamentally solve the environmental degradation caused by root damage in coal mining. Moreover they are difficult to spread and apply in mining area as their treatment cost is high. The bioremediation method is one of the most popular and advocated methods at home and abroad. As a good function of biological "fertilizer" arbuscular mycorrhizal fungi (AMF) has greater value and potential in an ecological environment treatment. In the process of coal mining, surface subsidence leads to plant root injury. For this problem, in this study, the mitigation effects of an arbuscular mycorrhizal fungus inoculation on the growth of root injured maize were investigated by soil pot experiments, which artificially simulated root damage caused by coal mining, with corn as the host plant and mining area degraded soils as the test matrix. The results indicated that AMF inoculation alleviated the adverse effects caused by root harm, and contributed to the growth of maize. The average dry weight per plant of the inoculation group was higher than that of the control group by 9.74 g. In addition, AMF inoculation significantly promoted the maize to take up mineral elements from the soil, and increased the content of glomalin and organic matter which existed in the rhizosphere soil of the injured maize. The contents of total glomalin and organic matter in the maize rhizosphere soil of the inoculation group were higher than that of the control group by 48.1% and 24.5% respectively. AMF inoculation improved the micro-environment of rhizosphere and made a contribution to the amelioration and fertilization of degraded soil in the mining area. It will provide technical support for land reclamation and ecological reconstruction by studying the effects of AMF on the growth of damaged plants.