Effects of different long-term fertilization on rhizosphere soil nitrogen mineralization and microbial community composition under the double-cropping rice field

ABSTRACT

Soil extracellular enzymes play an important role in regulating nitrogen (N) mineralization processes in paddy fields. Therefore, in this work, we determine the influence of a long-term fertilizer regime on rhizosphere soil N fertilization rates, soil enzymes, soil microbial community (bacterial ureolytic community (ureC), bacterial chitinolytic community (chiA)) under the double-cropping rice field in southern of China. The field experiment included the following fertilizer regimes: inorganic fertilizer alone (IF), rice straw and inorganic fertilizer (RF), 30% organic manure and 70% inorganic fertilizer (OM), without any fertilizer input as a control (CK). The results showed that rhizosphere soil N transformation rates in the paddy fields with OM and RF treatments were increased, compared with IF and CK treatments. Soil urease, β-glucosaminidase and arginase activities were significantly increased under OM and RF treatments. This result indicated that functional gene abundances of sub, npr and chiA were significantly greater under RF and OM treatments compared to IF and CK treatments. Soil bacterial ureolytic and chitinolytic communities were significantly changed by the different fertilization strategies. The practice of applying rice straw and organic manure seems beneficial for increasing rhizosphere soil N mineralization rates and microbial community diversity in the double-cropping rice fields.

KEYWORDS:

• Rice
• N fertilization rate
• soil microbial diversity
• soil enzyme activity
• gene abundance

Acknowledgments

This study was supported by the Hunan Provincial Natural Science Foundation of China (2022JJ30352), the National Natural Science Foundation of China (U21A20187), the National Key Research and Development Project of China (2023YFD2301403), and the Hunan science and technology talent lift project (2022TJ-N07).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Hunan Provincial Natural Science Foundation of China [2022JJ30352]; Hunan science and technology talent lift project [2022TJ-N07]; National Key Research and Development Project of China [2023YFD2301403]; National Natural Science Foundation of China [U21A20187].