Evaluation Of The Improvement Effect Of Four Giant Grasses On Poor Red Soil

In order to quantitative assessment the soil-improvement potential by planting giant grasses on infertility red soil,four giant grass,namely Pennisetum×Purpureum?Panicum virgatum?Miscanthus×giganteus and Miscarrthus lutarioriparia× sirrerrsis were selected as the experimental materials.The four giant grass was established at red soil at Liuyang(Hunan province)in 2011.As the biomass yield of four giant grass enters a stable period after four-year growth,the physicochemical properties of bulk soil of the four giant grass were tested form 2015 to 2018.Meanwhile,in 2018,the rhizosphere microbes of the four giant grass were tested using high-throughput sequencing.The main results are listed as flows:(1)After planting the four giant grass,the soil acidity was lighted due to the obvious decrease of p H with the advance of growing years,and its fertility was enhanced,which was characterized by the augmentation of organic matter and nutrients content(total nitrogen,total phosphorus,and total Potassium)in the red soil.With the increase of planting years,the investigated soil physicochemical properties showed a trend of first rising and then falling.Overall,the soil improvement effect is most significant after 3-4 years of planting.(2)Soil microbial communities significantly differed among different treatments.Cultivation of the four giant grass could increase the richness and diversity of soil fungal and bacterial groups.The change of microbial community structure is mainly related to soil p H,organic matter content,total phosphorus,and total potassium content.(3)Tall perennial grass cultivation can shape microbial communities.Specifically,The relative abundance of microbes with the function of lignocellulose degradation,nitrogen fixation,and metal restoration was significantly increased compared to CK,while the abundance of microbes which can lead to plant-pathogen was significantly decreased.