生物质炭调控烟草连作障碍的研究进展

Progress in the Regulation Effects of Biochar on Continuous Cropping Obstacles in Tobacco

烟草为忌连作作物,长期连作使烟草病虫害加剧,土壤有害微生物积聚,导致病原菌在土壤中占据主导优势,使得土壤营养元素失衡、作物自毒作用加重、土壤微生物区系失衡、酶活性改变。土壤微生态失衡,是烟草连作障碍产生的根本原因。生物质炭的多孔性、偏碱性及其养分特性,使其成为定向调控根际微生物种群特征、恢复并重建健康根际生态系统、克服烟草连作障碍的重要途径。通过物理、化学及生物学过程,生物质炭定向调控根际微生物的种群特征,恢复并重建健康的根际生态系统,增加土壤中有益微生物及细菌数量,使土壤微生物从真菌主导型向细菌主导型转化,使病原菌在土壤生态系统中失去主导优势,维持土壤微生态平衡,最终达到缓解和根治连作障碍的目的。通过分析植烟土壤连作障碍成因,综述生物质炭对烟草连作障碍的调控作用,并提出生物质炭调控烟草连作障碍的作用机制。

Tobacco is a crop avoiding from continuous cropping.A continuous cropping for long-term will intensify pests and diseases of tobacco,accelerate accumulation of harmful microorganisms in soil,and make pathogens predominate in soil,which would cause imbalance of soil nutrient elements,aggravation of crop autotoxicity,imbalance of soil microbial flora,and changes of enzymes activity.The imbalance of soil microhabitats is the basic reason of continuous cropping obstacles of tobacco.The biochar with porous,alkaline and special nutrient characteristics,makes it an important way to adjust rhizosphere microbial population characteristics directionally,to recover and rebuild healthy rhizosphere ecosystems,and to overcome continuous cropping obstacles in tobacco.Through physical,chemical,and biological processes,the biochar could directionally regulate the population characteristics of rhizosphere microbes,restore and rebuild healthy rhizosphere ecosystems,increase the number of beneficial microbes and bacteria in the soil,and transfer soil microbes dominate by fungi to the ones dominate by bacteria.The transformation can make the pathogen to lose the dominant advantage in the soil ecosystem,maintain the soil microhabitats balance,and ultimately alleviate and eradicate continuous cropping obstacles.In this paper,we analyzed the reasons for continuous cropping obstacles in tobacco-planting soil,reviewed the regulation effects of biochar on continuous cropping obstacles in tobacco,and then interpreted the acting mechanism of biochar on continuous cropping obstacles of tobacco.