Study On The Effect Of Biochar On Plant Growth And Chongming Tidal Flats Soil Properties

Biochar is a key carbon sequestration technologies, which could reduce carbon emissions, air pollution and agriculture, forestry and waste resource utilization. Biochar plays an important role on improvement of soil properties, promoting plant growth and carbon emission reduction. But there are many contradictory results in biochar application which may be related to the properties of biochar and soil type. Biochar was produced by the litter and straw of Chongming wetlands. The pot experiment was designed of four application rates(5、10、25 and 50 g·kg-1) plus an un-amended soil set as control. The plant experiment and field experiment was conducted to study the effect of biochar on soil carbon sequestration of Chongming Island and plant growth, finding the best amount of biochar which was beneficial to plant growth and soil carbon. The results are as follows.1) Biochar application could promote the growth of plants. Biochar effect on ryegrass growth mainly reflect most significant in root growth. The root is one of the important organs to absorb nutrients. The addition of biochar could increase soil porosity, affect the growth of plant root, and biochar application also increased soil available nutrient elements, the plant biomass accumulation also had a positive effect. Ryegrass grew best at the amount of 10 g/kg.2) Biochar application could change soil properties. Biochar could increase the soil pH, low concentration of biochar could increase the soil cation exchange capacity.When the biochar amount was low, total nitrogen of soil was increased, but nitrate nitrogen was reduced; when the biochar amount was high, total nitrogen and nitrate nitrogen content had increased. After biochar application, available phosphorus and available potassium amount had increased significantly, especially in high biochar amount.3) Biochar application could improve the soil carbon sequestration. Soil organic carbon content and biochar application amount linearly increased. After the biochar was added to the soil, it could improve the yield of plants, increase the ability of plants fixed CO2 in the atmosphere, thus attaining the goal of carbon emission reduction. Due to the addition of biochar to promote growth, increasing plants root biomass enhances soil organic carbon storage. And the increase of the over ground part of the organic matter can be made into biochar to a new cycle again.Considering of biochar on plant growth promoting effect and efficiency of carbon sequestration, the best content of biochar was 10 g·kg-1. With biochar application rise, the growth of ryegrass was increased. Biochar has an important influence on soil physical and chemical properties change, improves the soil carbon library, and provides nutrients for plants.