水氮互作对设施菜田土壤氮素形态组成以及细菌群落结构的影响

利用室内模拟培养试验,研究了不同水氮互作条件对设施菜田土壤氮素形态组成和细菌群落结构的影响.主因素为2种土壤水分条件:70％田间持水量和100％田间持水量;副因素为5种氮素添加形态:不施氮肥、纯无机氮、纯有机氮、2/3无机氮+1/3有机氮和1/3无机氮+2/3有机氮.结果表明:水氮互作效应对土壤无机氮含量和土壤细菌群落...

Effects of Water and Nitrogen Interactions on Soil Nitrogen Composition and Bacterial Community in the Protected Vegetable Field

The interactions of water and nitrogen (N) on soil bacterial community were analyzed in a simulated indoor incubation experiment. The main factor included soil moisture (70% and 100% field capacity), and the split factor was N addition form (no N application, pure inorganic N, pure organic N, 2/3 inorganic N + 1/3 organic N, and 1/3 inorganic N + 2/3 organic N). The results showed that the interaction of water and nitrogen had significant influences on the content of soil inorganic N and the Shannon and Simpson indices of soil bacterial community. Moreover, the content of soil inorganic N in the high soil water treatment was significantly decreased (P < 0.05), while the Shannon, Ace and Chao1 indices of soil bacterial communities were significantly increased (P < 0.01). The relative abundances of Aeromonas and Flavobacterium were increased with the increase of soil moisture content. Compared to the inorganic N treatment, the organic N treatments significantly accelerated the content of soil organic N after 30 days of incubation. With the addition of organic N, the relative abundances of Cellvibrio and Devosia also increased. In conclusion, although organic N fertilization in the protected vegetable field could not be conducive to the increase of soil available N, the dominant bacterial populations changed under the appropriate water condition. Soil carbon-N cycle is supposed to tend toward stability with the increased richness of the specific carbon assimilating bacteria. The results may provide a new insight for understanding the environment-driven mechanisms for soil carbon and N cycling functional microbes, in response to the different water and N managements in the protected vegetable filed.