A recommended rate for application of Chaetomium globosum ND35 fungus fertilizer on poplar plantations in China

摘要

Previous studies showed that Chaetomium globosum ND35 fungus fertilizer can improve the microbial community structure and enzyme activities of replanted soil.However, it remains unclear whether can improve the physiological and ecological characteristics of plants under successive rotation.In this study, we investigated the photosynthetic, physiological, and biochemical indexes including photosynthetic parameters, chlorophyll fluorescence, and chlorophyll content of 1-year-old poplar seedlings under seven different doses(range from 0 to1.67 g kg^(-1)) of C.globosum ND35 fungus fertilizer to study the effects of fungus fertilizer on photosynthesis of Poplar.Our results showed that:(1) With increasing application of fungus fertilizer in replanted soil, chlorophyll content of poplar leaves(Chl) increased, while physiological indexes such as electron transport rate(ETR),net photosynthetic rate(P_n), quantum efficiency(U),nitrate reductase(NR) activity and root vigor initially increased and then declined.Meanwhile, heat dissipation that depended on the xanthophyll cycle declined and nonphotochemical quenching(NPQ) initially increased and then decreased.When the dose of C.globosum ND35 fungus fertilizer was 0.67 g kg^(-1)(T3) and 1.00 g kg^(-1)(T4), excess light energy of photosynthetic apparatus was reduced, and photosynthetic apparatus distributed more light energy to the direction of photochemical reactions,which improved the efficiency of energy use.Plant height and biomass of leaves, stems, and roots were maximum at T3.We conclude that applying appropriate amounts of C.globosum ND35 fungus fertilizer can improve root physiological activity and capacity for use of light by poplar leaves.This can improve the operating states of the photosynthetic apparatus and lead to increased photosynthetic efficiency of poplar leaves and accumulation of dry matter.This suggests a strategy to alleviate the successive rotation obstacle of soil nutrient depletion.