增施生物有机肥对烤烟光合特性及根际土壤微生物的影响

Effects of Bio-organic Fertilizer on Flue-cured Tobacco Photosynthetic Characteristics and Rhizosphere Soil Microorganism

为探讨生物有机肥作用下烤烟光合特性及根际土壤微生物的变化,采用随机区组试验,研究了增施生物有机肥对烤烟光合参数、土壤微生物数量和多样性及碳源利用力的影响。结果表明,增施生物有机肥改变了烤烟的光合特性,烟叶SPAD值、净光合速率、蒸腾速率、气孔导度和胞间CO_(2)浓度均显著提高,以70%化肥+4500 kg·hm^(-2)生物有机肥效果最优;适量增施生物有机肥不仅可提高土壤根际细菌、真菌和放线菌的数量,还可提高土壤微生物群落的Shannon、Simpson和McIntosh指数,但过量增施效果不明显;主成分分析表明,增施生物有机肥使土壤微生物群落对糖类、氨基酸类、聚合类、酚类、胺类和羧酸类6类碳源的代谢特征产生了差异,其中最有利于糖类和聚合类碳源的代谢。综合而言,增施生物有机肥能显著提升烤烟光合代谢效率,强化碳代谢特征,并促进土壤微生物数量和群落多样性的形成,以70%化肥+4500 kg·hm^(-2)生物有机肥配比为宜。

The experiment with randomized block design was carried out to explore the influence of bio-organic fertilizer on flue-cured tobacco photosynthetic characteristic and rhizosphere soil microorganism,and research the effects of different application ratios of bio-organic fertilizer on photosynthetic parameters of flue-cured tobacco,quantities and diversities of microorganism in soil,and carbon utilization. Results showed that the application of bioorganic fertilizer made the photosynthetic characteristics of flue-cured tobacco,such as the SPAD values,net photosynthetic rate,transpiration rate,stomatal conductance and intercellular CO_(2)concentration significantly increased,the treatment of 70% chemical fertilizer and 4 500 kg·hm^(-2) bio-organic fertilizer had the best effect.Appropriate application of bio-organic fertilizer could not only increase the number of bacteria,fungi and actinomycetes,but also improve the indexes of Shannon,Simpson and McIntosh,but the effect of excessive application was not significant. The results of principal component analysis showed that the soil microbial community had different metabolic characteristics of 6 type of carbon sources,such as carbohydrate,amino acids,polyphenolic amines,carboxylic acids,etc.,which were most beneficial to the metabolism of carbohydrates and polymers. To sum up,the application of bio-organic fertilizer could significantly improve the photosynthetic and metabolic efficiency of flue-cured tobacco,enhance the carbon metabolism characteristics,and promote the formation of microbial quantities and community diversities. The treatment combining 70% chemical fertilizer and 4 500 kg·hm^(-2) of bio-organic fertilizer was optimal.