Effects Of Biochar In Culture Media On Quality And Growth Of Dendrobium Officinale

Recently, there are many reports on the research of soil improvement and soil heavy mental contamination of biochar, especially the intensive study on soil environmental function, soil microbial and plant growth has been further explored. However, the study on the impact of biochar as a growing media also rarely reported, especially on the effects of the growth and quality of Dendrobium officinale, which is a precious Chinese medicine. This can be provided an important reference value and a directive significance for Dendrobium officinale planting substrate modification. In this paper, the bamboo biochar is obtained by particle size and leaching tests, and adding different amounts of the biochar to two base matrix in order to study the effects on matrix pH, EC values, nutrient content and the effects on agronomic characters, nutrients, trace elements, the polysaccharide content and yield of Dendrobium officinale. The main results are as follows.(1) The pH of biochar by water leached ranged from 8.96 to 9.14, and EC from 161.08 and 183.40 μS/cm, and the pH and EC are suitable for the growth of Dendrobium officinale. However, the pH of biochar rinsed with distilled water remained higher, and EC value is small, opposite forl% dilute hydrochloric acid leached, and the two methods are not suitable for the growth of Dendrobium officinale. Biochar for the particle size more than 2mm can provide more aeration porosity of the matrix. Therefore, this study shall choose these biochar, which are particle diameter over 2mm and leached by water.(2) Effects of biochar on the physicochemical properties of matrix. Compared with CK1, the matrix of pH and EC under the addition 5% and 10% of biochar can meet the requirements of the growth of Dendrobium officinale, and the matrix of pH for 20% is not conducive to Dendrobium officinale growth. Compared with CK2, the pH value of the matrix at the beginning increased, then with the matrix leached and the interaction with matrix gradually reduced, and that meet the needs of Dendrobium officinale growth. EC of matrix can meet the demand of Dendrobium officinale growth. Therefore, biochar added 5% or 10% is more appropriate Dendrobium officinale growth.(3) Effects of biochar on the growth of Dendrobium officinale. With increasing amounts of biochar addition on matrix of pine bark mixed with peat, it is increased that stem diameter growth rate, the number gradually of Dendrobium officinale, while the survival rate, height, spacing section, root length decreased. The number of germination and trees were improved for adding 5% and 10% of biochar. When the dosage of biochar is 10%, it is significantly reduced survival rate. Biochar has no obvious influence on the production, final stem diameter, leaf length, leaf width, chlorophyll of Dendrobium officinale. With increasing amounts of biochar addition in Diatomite and peat mix matrix, the survival rate, yield, plant height, growth rate Dendrobium, stem diameter growth rate, section spacing of Dendrobium officinale increased gradually, and root number increased after reduction first, long instead. There is a negative impact of 5% addition level for leaf length, leaf width and chlorophyll, to increase the number of trees of of Dendrobium officinale promoted when the rate of application biochar added 10%.(4) Effects of biochar on the quality of Dendrobium officinale. With adding biochar on matrix of pine bark mixed with peat, biochar could make the increase of the content of polysaccharide promoting, and promote the absorption of Zn, Co. The 5% amount of biochar can promote the absorption of K, inhibit the absorption of Cd. With adding biochar on matrix of Diatomite mixed with peat, biochar could promote the absorption of Zn, Co. The 10% amount of biochar can promote the absorption of potassium and the content of polysaccharide promoting. Adding biochar in two hybrid matrix can not promote the absorption of phosphorus of Dendrobium officinale.