EFFECTS OF BIOCHAR ON ROOT MORPHOLOGY CHEMICAL PROPERTIES OF RHIZOSPHERE SOILAND NITROGEN ACCUMULATION OF WHEAT (Triticum Aestivum L.)

摘要

Biochar has proved to substantially improve plant growth and yields. The increased plant growth may come with the response of plant root and rhizo-sphere induced by biochar, which is important to nu-trient uptake. However, influence of adding biochar on root and the rhizosphere soil has not been well understood. Maize straw biochar (MBC)(pyrolysed at～350°C)was added into soil at the rates of 0, 1,2.5 and 5(w/w)respectively to investigate their effects on root morphological, rhizosphere soil chemical properties and nitrogen accumulation of wheat.The results indicated that MBC application into soil increased wheat biomass, as well as the total root length, root surface area and root volume were significantly increased by 25.9-35.4,18.8-49.0and 28.2-74.1, respectively. However, the wheat biomass and root traits did not increase with increas-ing MBC rate, suggesting that excessive biochar ad-dition may not lead to higher biomass and the bio-char rate should be controlled at an optimal level. Moreover,Adding MBCmarkedlyincreased the rhi-zosphere soilpH,CECandTNby 16.6-25.616.1-17.5 and 10.3-21.8 respectively,indicating that MBC could enhance the wheat rhizosphere ef-fect. Nevertheless, biochar addition lowered NAE. This indicated that less nitrogen was absorbed by the wheat but more biomass was produced using the equivalent amount of nitrogen in the MMBC-amended soil compared to that of the control, thus, MBC addition may decrease nitrogen fertilizer de-mand for wheat growth.