Adding Biochar To Help Restore Microorganisms After Soil Disinfection

Science and Technology Daily (reporter: Ouyang Canbin, Correspondent of Ma Aiping, Fang Wensheng) Recently, the soil pest prevention and control innovation team of the Institute of Plant Protection, Chinese Academy of Agricultural Sciences, combined with multi group analysis and isotope labeling, revealed the mechanism of biochar regulating the restoration of soil microbial community and soil nitrogen metabolism after fumigant disinfection. Relevant research was published in Hazardous Materials.
Fumigant disinfection plays an important role in the prevention and control of soil borne diseases and the improvement of cultivated land quality. In recent years, the innovation team for the prevention and control of soil pests has carried out a series of studies to clarify the impact of fumigant disinfection on soil microbial communities and ecological functions. The results showed that the effects of soil disinfection on microbial diversity and community structure varied with the types of fumigants and soil types, and the diversity and abundance of bacteria and fungi could be restored to the control level within 2 months. Fumigant disinfection inhibits or promotes the expression of key genes of soil microbial pathway, interferes with the cycle of soil carbon, nitrogen and phosphorus, and reveals the "fertilizer effect" and yield increasing mechanism of fumigant disinfection by changing the existing form and quantity of soil available nitrogen and phosphorus from the perspective of soil microecology.
On the basis of the above work, the scientific research team jointly applied the macro genome analysis technology and the nitrogen and oxygen double isotope labeling method, and found that the biochar mixed in the farmland disinfected with fumigant can effectively promote the recovery of functional microorganisms such as ammonia oxidizing bacteria (AOB), ammonia oxidizing archaea (AOA), nitrite reduction (nirS/K) in the nitrogen cycle process, promote the consumption of ammonium nitrogen and nitrate nitrogen, and thus accelerate the process of soil nitrogen metabolism, The nitrous oxide emission changes from the denitrification process to the denitrification path of nitrifying bacteria. The results provide an effective way for the restoration of soil microecology and the directional regulation of soil ecological function after disinfection.