Effect of Earthworm Inoculation on Repairing Fertility of Lateritic Red Soil Degraded by Highway Construction and Plant Growth of Amaranthus hypochondriacus L.

Two earthworm species,Eisenia foetida and Amynthas robustus,were grown in a pot experiment with Amaranthus hypochondriacus L.to study the effects of the different ecological types of earthworms on the fertility recovery and ecological restoration of the degraded lateritic red soil due to highway construction.Three treatments,i.e.,20 E.foetida,20 A.robustus,and 10 E.foetida plus 10 A.robustus,along with control(CK without earthworm inoculated)were applied.The results showed that the plant height,stem diameter,biomass and NPK accumulation of the A.hypochondriacus L.plants in the treatment groups were significantly higher than those in CK(P<0.05).E.foetida(i.e.,an epigeic earthworm species)enhanced the plant growth and nutrient accumulation more significantly than A.robustus(i.e.,an endogeic species).By using both earthworm species simultaneously in the soil,no synergistic effect was observed.Nonetheless,the presence of either of the earthworms enhanced the organic decomposition and nutrient activation in the soil significantly improving the plant growth.However,since soil improvement depends on the properties and conditions of the soil as well as the species of the inoculated earthworms,it would be necessary to firstly obtain the relevant information prior to the implementation.