Effects Of Five Traditional Chinese Medicine Residues On Soil And Growth Of Wheet

Traditional Chinese medicine residues(TCMR)refer to the wastes generated during the processing of traditional Chinese medicine,which show dual values of medicine and nutrition.The residues from the non-medicinal parts are less polluted,which could be returned to field directly.It is necessary to clarify the effects of TCMR retention,because residues may affect plant growth due to their medicinal ingredients.To explore the feasibility of returning five TCMR(Danshen,Huangbo,Huangqi,Kushen and Gancao)to field,this work investigated their influences on soil properties and plant growth through decomposition and pot experiments in a short-term.This work aims to provide theoretical basis and insight for agricultural application of TCMR.Below are results.1.Difference was observed in the decomposition rates of five residues,among them Huangqi residue showed the highest decomposition rate.All of the residues increased soil moisture,but soil p H and the activities of soil enzymes such as urease and catalase were altered substantially by short-term residue retention(30 days).Addition of five residues(10 g/kg soil)15 days before sowing wheat had no significant impact on seed germination and seedling growth.2.Huangqi residue(10 g/kg soil)promoted the growth of wheat seedlings.This result was presumably ascribed to the improved soil fertility(soil organic matter and available nutrient contents),increased activities of soil urease and sucrase,as well as the changed soil microbial community;the combination of Huangqi residue and Bacillus subtilis showed higher promotion effect on the growth of wheat seedlings.3.Gancao residue showed a short-term inhibitory effect on the growth of wheat and other crop seedlings.This drawback could be alleviated or eliminated by extending the retention time appropriately.Returning Huangbo residue(20 g/kg soil)and Kushen residue(20 g/kg soil)to field with small specification(< 2 mm)also promoted the growth of wheat seedlings,but it did not show the similar effect with large specification.The promotion effect of Danshen residue(20 g/kg soil)was not affected by different specifications.4.High-throughput sequencing results showed that returning Huangqi residue and Danshen residue to field could improve the rhizosphere soil microenvironment of wheat,but differences were observed between the two residues.To sum up,returning the five residues to field could improve soil physical and chemical properties.Besides,returning Danshen,Huangbo,Kushen,Huangqi and Gancao residues to field did not retard the growth of wheat seedlings.This work indicated that all the 5 residues are worth being returned to field.