RESPONSES OF RHIZOSPHERE SOIL PHYSICOCHEMICAL PRPERTIES, ENZYME ACTIVITIES AND BACTERIAL COMMUNITY TO INTERCROPPING Sophora Viciifolia HANCE IN Pennisetum Sinese ROXB PLANTATIONS IN SUBTROPICAL CHINA

Pennisetum sinese Roxb has been identified as an important forage crop to produce feed and improve livestock production in subtropical China; grass-legume intercropping is one of the most widely planting patterns for improving productivity. Here, intercropping of P. sinese with Sophora viciifolia Hance was carried out in southwest China, and soil physicochemical properties and biological indicators were investigated. Our studies showed that the intercropping with P. sinese-S. viciifolia altered the rhizosphere soil physicochemical properties (total nitrogen-TN, total phosphorus-TP, nitrate nitrogen-NO3--N, and available potassium-AK contents) and enzyme activities (glutamine synthetase-GS, acid phosphatase-ACP, ȕ-1,4-N-acetylglucosaminidaseNAG and nitrogen fixation-Nit activities). Compared with the monoculture treatment, the intercropping treatment had a considerably higher abundance of Proteobacteria, Actinobacteria and Firmicutes but a considerably lower abundance of Planctomycetes and Acidobacteria at the phyla level. Moreover, the abundances of Streptomyces, AKYG587 and Bacillus were higher, and abundances of Gemmata, Haliang ium and Candidatus_Udaeobacter were lower under intercropping treatment compared to monoculture treatment at the genera level. RDA analyses revealed that soil bacterial community was strongly affected by organic matter (OM), total phosphorus (TK) and moisture content (WC) in the monoculture treatment, whereas strongly correlated by pH, TN, TP and ammonium (NH4+-N) in the intercropping treatment. This study implies that soil bacterial community was largely dependent on agricultural management practices (monoculture or intercropping treatment).